•We prepare the ultrathin mesoporous ZnCo2O4 nanosheets (∼4.3 nm) via a facile hydrothermal approach.•The ultrathin ZnCo2O4 nanosheets present outstanding lithium-storage performance.•Even at 5 A g−1, the ZnCo2O4 nanosheet electrode still presents a relatively high specific capacity of 410 mAh g−1.Transition-metal oxides have been widely explored as the anode materials for lithium-ion batteries (LIBs) because of its low cost and high energy/power density. However, the electrode pulverization and capacity fading during cycling lead to poor cycling performance. Herein, ultrathin ZnCo2O4 nanosheets with desired mesoporosity and high surface area are prepared by a facile hydrothermal approach. Such ZnCo2O4 nanostructures show excellent lithium storage performance as anode materials for LIBs. At a current density of 1 A g−1, the ultrathin ZnCo2O4 nanosheets present an initial specific capacity of 1251 mAh g−1 and the specific capacity remains at ∼810 mAh g−1 even after 200 discharge–charge cycles.Ultrathin ZnCo2O4 nanosheets with desired mesoporosity and high surface area are prepared by a facile hydrothermal approach. Such ZnCo2O4 nanostructures show excellent lithium storage performance as anode materials for LIBs. At a current density of 1 A g−1, the ultrathin ZnCo2O4 nanosheets present an initial specific capacity of 1251 mAh g−1 and the specific capacity remains at ∼810 mAh g−1 even after 200 discharge–charge cycles.Download high-res image (290KB)Download full-size image

The catalytic activity of counter electrodes (CEs) severely restricts the photovoltaic conversion efficiency of dye-sensitized solar cells. However, electrons trapped by bulk defects greatly reduce the catalytic activity of the CE. In this study, we report a novel In2S3–C–Au hybrid structure designed by simply decorating Au particles on the surface of carbon-coated hierarchical In2S3 flower-like architectures, which could avoid the abovementioned problems. This effect can be attributed to the unique contribution of indium sulfide, carbon, and Au from the hybrid structure, as well as to their synergy. Electrochemical measurements revealed that the hybrid structure possessed high catalytic activity and electrochemical stability for the interconversion of the redox couple I3−/I−. Moreover, this superior performance can be incorporated into the dye-sensitized solar cells system. We used this hybrid structure as a counter electrode by casting it on an FTO substrate to form a film, which displayed better photovoltaic conversion efficiency (8.91%) than the commercial Pt counterpart (7.67%).

•The Bi2MoO6 hollow mesoporous nanostructured have been successfully synthesized by a template-free solvothermal process.•The Bi2MoO6 hollow mesoporous spheres exhibited greatly photocatalytic activity for photodegradation of tetracycline (TC).•The Bi2MoO6 hollow mesoporous spheres photocatalytic superiority would be applied in the fields of photocatalytic degradation hazardous pollutants.The Bi2MoO6 hollow mesoporous nanostructured have been successfully synthesized by a template-free solvothermal process. The structural and morphological of Bi2MoO6 was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The obtained Bi2MoO6 hollow mesoporous spheres exhibited greatly photocatalytic activity for photodegradation of tetracycline (TC) aqueous solution, which could be attributed to the synergistic effect of catalysts structure including large surface area, the energy band structures, porous hollow sphere structure and light absorbance. The Bi2MoO6 hollow mesoporous spheres photocatalytic superiority would be practicable for the application in the fields of photocatalytic degradation hazard pollutants.The highly crystalline and high-performance of the Bi2MoO6 hollow mesoporous spheres materials prepared via simple hydrothermal reaction. The obtained Bi2MoO6 hollow mesoporous spheres performed high photocatalytic activities for the TC under irradiation due to the Bi2MoO6 hollow mesoporous spheres owns higher surface area and hollow porous spheres structure. The study provides a general and effctive method in the fabrication of hollow mesoporous spheres that may show a variety of applications for environmental treatment.Download high-res image (127KB)Download full-size image

Responsible development of nanotechnology calls for improved understanding of how nanomaterial surface energy and reactivity affect potential toxicity. Here, we challenge the paradigm that cytotoxicity increases with nanoparticle reactivity. Higher-surface-energy {001}-faceted CdS nanorods (CdS-H) were less toxic to Saccharomyces cerevisiae than lower-energy ({101}-faceted) nanorods (CdS-L) of similar morphology, aggregate size, and charge. CdS-H adsorbed to the yeast’s cell wall to a greater extent than CdS-L, which decreased endocytosis and cytotoxicity. Higher uptake of CdS-L decreased cell viability and increased endoplasmatic reticulum stress despite lower release of toxic Cd2+ ions. Higher toxicity of CdS-L was confirmed with five different unicellular microorganisms. Overall, higher-energy nanocrystals may exhibit greater propensity to adsorb to or react with biological protective barriers and/or background constituents, which passivates their reactivity and reduces their bioavailability and cytotoxicity.

Hollow and hybrid nanomaterials are excellent electrocatalysts on account of their novel electrocatalytic properties compared with homogeneous solid nanostructures. In this report, NiSe-Ni3Se2 hybrid nanostructure with morphology of hollow hexagonal nanodisk was synthesized in situ on graphene. A series of NiSe-Ni3Se2/RGO with different phase constitutions and nanostructures were obtained by controlling the durations of solvothermal treatment. Because of their unique hollow and hybrid structure, NiSe-Ni3Se2/RGO hollow nanodisks exhibited higher electrocatalytic performance than NiSe/RGO and solid NiSe-Ni3Se2/RGO nanostructure for reducing I3– as counter cell (CE) of dye-sensitized solar cells (DSSCs). Additionally, NiSe-Ni3Se2/RGO hollow nanodisks achieved much lower charge transfer resistance (Rct = 0.68 Ω) and higher power conversion efficiency (PCE) (7.87%) than those of Pt (Rct = 1.41 Ω, PCE = 7.28%).

Novel bi-component-active hierarchical ZnO/ZnCo2O4 (ZZCO) nanosheets with mesostructures are successfully prepared through a convenient and practical hydrothermal route followed by a calcination process. When evaluated as anode materials for lithium-ion batteries (LIBs), the bi-component-active hierarchical ZZCO nanosheets with mesostructures exhibit highly reversible lithium storage capacity, and strong cycling stability at the 500 mA g−1 rate for 150 cycles. More significantly, the hybrid ZZCO presents an exceptionally high rate capability up to the 2 A g−1 rate.

Transition metal chalcogenides with mesoporous structure are of special interest for application in electrocatalytic reactions due to their ample unique properties and functionalities. Nevertheless, relevant research on mesoporous Ni0.85Se applied as electrocatalysts is rare. In this contribution, mesoporous Ni0.85Se spheres consisting of numerous primary particles are synthesized via a facile self-assembly route. Mesoporous Ni0.85Se spheres exhibit higher electrocatalytic activity (PCE = 7.24%) for the reduction of triiodide to iodide and lower charge-transfer resistance (Rct = 2.40 Ω) than Ni0.85Se nanoparticles (PCE = 6.73%, Rct = 3.46 Ω) at the electrolyte–electrode interface in dye-sensitized solar cells (DSSCs). In order to further enhance the overall electrocatalytic performance of mesoporous Ni0.85Se spheres, reduced graphene oxide (RGO) and single wall carbon nanotubes (SWCNTs) are introduced by facile physical mixing. RGO and SWCNT not only improved the charge transfer ability, but also yielded favorable synergistic catalytic effects with mesoporous Ni0.85Se spheres. Simultaneously, the PCE values of Ni0.85Se + 6 wt% RGO and Ni0.85Se + 9 wt% SWCNT reach 7.87% and 7.74%, respectively, which are both higher than Pt (7.56%).

•Through a simple and low-cost route to prepare ultrathin Mn3O4 nanosheets.•The ultrathin Mn3O4 nanosheets exhibit a higher reversible capacity and stronger cycling stability.•This work is favorable to explore advanced ultrathin nanosheets structure as anode materials for LIBs.We use deionized water and ethanolamine as solvent and manganese chloride as Mn sources under stirring to successfully prepare the ultrathin two-dimensional (2D) graphene-like nanosheet materials. The as-obtained ultrathin Mn3O4 nanosheets own high surface area (192.46 m2 g−1) through a simple and low-cost route at room-temperature. Importantly, the ultrathin Mn3O4 nanosheets exhibit a higher reversible capacity and stronger cycling stability (~520 mAh g−1 at 200 mA g−1 after 300 cycles) as anode materials for LIBs.The ultrathin Mn3O4 nanosheets exhibit a higher reversible capacity and stronger cycling stability as anode materials for LIBs.

Mesoporous Ni0.85Se nanospheres grown on graphene were synthesized via the hydrothermal approach. Because of the exceptional electron-transfer pathway of graphene and the excellent catalytic ability of the mesoporous Ni0.85Se nanospheres, the nanocomposites exhibited excellent electrocatalytic property as the counter electrode (CE) of dye-sensitized solar cells. More catalytic active sites, better charge-transfer ability and faster reaction velocity of Ni0.85Se@RGO (RGO = reduced graphene oxide) CE led to faster and more complete I3– reduction than Pt, Ni0.85Se, and RGO CEs. Furthermore, the power conversion efficiency of Ni0.85Se@RGO CE reached 7.82%, which is higher than that of Pt CE (7.54%). Electrochemical impedance spectra, cyclic voltammetry, and Tafel polarization were obtained to demonstrate positive synergetic effect between Ni0.85Se and RGO, as well as the higher catalytic activity and the better charge-transfer ability of Ni0.85Se@RGO compared with Pt CE.Keywords: DSSCs; graphene; mesoporous nanospheres; Ni0.85Se;

Ultralong one-dimensional (1D) nanostructures including nanowires or nanotubes have been extensively studied because of their widespread applications in many fields. Although a lot of methods have been reported to prepare In2S3 nanotubes, approaching these nanotubes through one-pot solution synthesis is still extremely difficult, probably because of the intrinsic isotropic crystal growth characteristic of In2S3. In this article, we demonstrated a self-assembly approach for hydrothermal synthesis of In2S3 nanotubes/graphene composites, which contain ultralong (up to 10 μm) In2S3 nanotubes on graphene substrate. The influence of several important synthetic parameters on the final products has been systematically investigated. Importantly, the as-prepared In2S3 nanotubes/graphene composites can be easily cast on FTO to form a film, which can be used as a counter electrode. Our research indicates that the as-fabricated counter electrode exhibits excellent electrocatalytic activity toward the iodide species (I–/I3–) reduction reaction and very high energy conversion efficiency (8.01%) in dye-sensitized solar cells.Keywords: dye-sensitized solar cells; electrocatalytic activity; graphene; In2S3; nanotube

Composites of TiO2–B nanorods and reduced graphene oxide (RGO) were prepared through a simple two-step hydrothermal process followed by subsequent heat treatment in argon. The obtained TiO2–B nanorods had a small size (∼10 nm diameter of the nanorod) and a uniform morphology. Importantly, the synergistic effect of RGO nanosheets and nanostructured TiO2—B leads to electrodes composed of the TiO2–B–RGO nanocomposites which exhibit excellent cycling stability and rate capability (260 mA h g−1 at 1 C and 200 mA h g−1 at 2 C after 300 cycles and 140 mA h g−1 at 20 C).

Hierarchical flower-like Nb2O5 microspheres have been prepared via a facile hydrothermal approach without any additives. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were employed to clarify the structure and morphology of the Nb2O5 microspheres. Structure and morphology evolution mechanisms have been proposed for the hierarchical structure in detail. During the symmetric Ostwald ripening, the resultants formed aggregates composed of two-dimensional nanoflakes as building blocks. Photocatalytic activity of the as-prepared Nb2O5 microspheres was evaluated by the photodegradation of Rhodamine B (RhB), and over 90% of RhB was degraded within 30 min under the irradiation of UV light. The as-prepared Nb2O5 exhibits higher photocatalytic activity than commercial Degussa P25. Moreover, Nb2O5 was tested as an anode material of lithium-ion batteries, which displayed high reversibility and excellent rate stability at a current density of 50 mA g−1.

A simple and steerable method was adopted to synthesize well-distributed rutile TiO2 nanobundles on reduced graphene oxides through two-step hydrothermal methods. The rutile TiO2–RGO composites were used as the anode materials in lithium ion batteries for investigation, which had an original morphology and a reversible capacity of 300 mA h g−1 at 0.6 C and 200 mA h g−1 at 1.2 C after 500 cycles.

3D mesoporous BiOBr microspheres via a one-step solvothermal process without templates were synthesized. The as-synthesized material was characterized by XRD, XPS, FESEM, TEM, UV-Vis and nitrogen adsorption techniques. The photodegradation behavior of the non-steroid anti-inflammatory drug (NSAID) ibuprofen (IBP) in aqueous BiOBr suspension was investigated under simulated solar light irradiation. The photocatalytic activity of the as-prepared 3D mesoporous BiOBr microspheres was excellent. IBP photodegradation intermediates were detected by GC/MS analyses, and a detailed reaction pathway was proposed. Luminous bacteria (Vibrio qinghaiensis) toxicity evaluation showed the decrease of the toxicity of the photodegradation intermediates. Based on the results, 3D BiOBr could be a promising catalyst on irradiation by visible light, and even under sunlight.

3D cubic microporous In2O3 has been successfully obtained by calcining the as-synthesized cube In(OH)3–InOOH precursor at 300 °C for 2 hours. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were employed to clarify the structures and morphologies of both the cubic In(OH)3–InOOH precursor and cubic In2O3. The formation mechanisms of the In(OH)3–InOOH precursor and cubic In2O3 were investigated. As an important semiconductor photocatalytic material, its photocatalytic properties have been tested. Under the irradiation of UV light, the cubic microporous In2O3 exhibits excellent photocatalytic properties to degrade eosin B (EB), which presents ∼95% degradation of EB after 3 hours and the degradation rates is 10.5 times that of commercial In2O3 powder. The high separation efficiency of electron–hole pairs results in high photocatalytic activity. Furthermore, the photoluminescent properties of the cubic microporous In2O3 have been investigated as well.

We synthesized two kinds of NiSe2 crystalline material grown on graphene (microsphere NiSe2/RGO and octahedron NiSe2/RGO) through a facile hydrothermal route. Their catalytic activities as the counter electrodes (CEs) in dye-sensitized solar cells (DSSCs) were investigated through I–V curves and conversion efficiency tests. Attributed to the outstanding carrier transfer properties of graphene nanosheets, the NiSe2/graphene materials exhibited an excellent electrochemical performance, and microsphere NiSe2/RGO showed a better electrocatalytic performance as the CE for the reduction of triiodide than that of Pt. Furthermore, Tafel polarization and electrical impedance spectroscopy (EIS) were performed to evaluate the electrocatalytic activity of the as-prepared CEs.

As nano-materials (NMs) are incorporated into ecosystems in increasing amounts, it is urgent to understand the impact of these materials on various biological populations. Lead sulfide (PbS) NMs, such as PbS nano-dendrites and nanoparticles, are important semiconductor materials. While PbS nanoparticles have been implicated to be a risk to organisms, the toxicity of PbS nano-dendrites remains unknown. In this study, we tested the toxicity and related mechanisms of two synthesized PbS nano-dendrites to the model organism Saccharomyce cerevisiae. The results demonstrated that the dendrites may interact with the yeast cells, resulting in the degradation of these dendrites and consequent production of nanoparticles. Moreover, this interaction led to severe damage to the yeast cell wall and intracellular reactive oxygen species (ROS) accumulation, which contribute to the toxicity of the dendrites. These results indicated that the interaction between NMs and the organisms should be included in the studies of nanotoxicity.

A relatively green hydrothermal route was employed to successfully synthesize Bi2WO6 hierarchical microspheres assembled by nanosheets. As-synthesized Bi2WO6 was characterized by X-ray diffraction, Raman spectra, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption and desorption isotherms and UV–vis diffuse reflectance spectroscopy. In acidic and neutral solutions, Bi2WO6 hierarchical microspheres exhibited excellent photocatalytic performance for Rhodamine B (RhB) degradation under simulated sunlight irradiation. Bi2WO6 microspheres could keep stable in acidic and basic solutions. The photodegradation of RhB was achieved by holes and O2− radicals attack in the Bi2WO6 microspheres suspension.

Through first-principles computations, we compared the photocatalytic properties of (102) and (001) facets within BiOBr. Due to the surface states, the (102) facets of BiOBr have lower conduction band minimum and higher valence band maximum, compared with the (001) facets. Therefore, the (102) facets have more efficient electron injection, higher redox potential of photoinduced hole, and smaller band gap, which may result in better photocatalytic performances. Also, we prepared BiOBr-102 and BiOBr-001 samples with dominantly exposed (102) and (001) facets, respectively, and found red-shift absorption, and enhanced photodegradation rate of Rhodamine B in BiOBr-102, which agree well with the computations. Therefore, BiOBr samples with dominantly exposed (102) facets are superior in photocatalysis, and the results demonstrate the critical role of facet orientation in photocatalyst design.

Through hybrid density functional theory, we computationally designed two-dimensional ZnO–GaN heterostructured nanosheets, and investigated their structural, electronic and optical properties. As a result of the type-II band alignment of ZnO and GaN, both bare (ZnO)m(GaN)n and hydrogenated H-(ZnO)m(GaN)n (m, n ≥ 3) nanosheets have band gaps below 3.0 eV with visible-light absorption accordingly, which is confirmed by computed optical properties. Also, photo-induced electrons and holes are directly separated and spatially confined in the ZnO and GaN regions, respectively, which is preferable for restraining ultrafast recombination of photo-excited e−–h+ pairs. Moreover, due to the perfect lattice matching of ZnO and GaN crystals, the heterostructured ZnO–GaN nanosheets have few crystal defects at the interfaces, which act as excitons' recombination centres. ZnO–GaN heterostructured nanosheets are promising high-performance materials for solar harvesting.

Through density functional theory (DFT) computations and experimental tests, we investigated the catalytic properties of Sb2S3 crystals with different facets used as counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). The computations show that, compared with the (151) facet, the (211) facet has greater surface activity and better electrical conductivity but markedly lower band-edge levels, resulting in comparable catalytic activities for these two facets. To verify these predictions, we synthesized two Sb2S3 nanowire bundles, predominantly with exposed (151) and (211) facets, and found that DSSCs with these Sb2S3 CEs have similar I–V curves and conversion efficiencies, which confirms the computations and suggests that the surface activity, electrical conductivity, specific surroundings, and band-edge positions should all be considered in the design of semiconductor CEs for DSSCs.

Via density functional theory computation and experimental validation, we have compared the catalytic activities of different facets within Bi2S3, as counter-electrode (CE) materials for dye-sensitized solar cells (DSSCs). The (130) facet has the largest surface energy, the best electronic conductivity, and the highest position of conduction band minima, indicating the most effective electron transfer from CEs to I−3 and the highest catalytic activities of Bi2S3 with (130) facets. To testify the computations, we also synthesized flower-like Bi2S3 nanostructures with dominantly exposed (130) and (211) facets, respectively, and investigated their catalytic activities through impedance spectra, I–V curves and conversion efficiency tests. DSSCs with (130) and (211) faceted Bi2S3 CEs exhibited conversion efficiencies of 3.5% and 1.9%, respectively, which further confirmed the superiority of (130) facets within Bi2S3. The findings provide some clues for designing and applying low-cost Pt-free DSSC CE materials from inorganic nanostructures.

3D mesoporous BiOBr microspheres were fabricated via a facile, rapid and environmentally friendly one-step solvothermal process without using templates. The physiochemical properties of BiOBr were characterized by XRD, FESEM, TEM and nitrogen adsorption techniques. The photodegradation behaviors of bisphenol A (BPA) catalyzed by BiOBr were investigated under simulated solar light irradiation. The photocatalytic activities of the BiOBr were superior to that of commercial Degussa P25 TiO2. Particular attention was paid to the identification of intermediates and acute toxicity of photocatalytic degradation samples of BPA by GC–MS and bioluminescence bacteria, respectively. Deducing from the results, BiOBr can be a good kind of catalyst irradiated by visible light even under sunlight.

Sunlight-induced photodegradation of rhodamine B over Ag3PO4 has been observed. Nanosized Ag3PO4 was synthesized by a facile ion-exchange route. X-ray powder diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, the Brunauer–Emmett–Teller surface area, UV–vis diffuse reflectance spectroscopy and photoluminescence spectra were employed to investigate the phase structure, morphology and optical property of the Ag3PO4 product. Nearly 100% of rhodamine B was degraded after a very short irradiation time using simulated sunlight in Ag3PO4 suspension, and the total organic carbon measurement revealed that a high degree of mineralization was achieved in the present photocatalytic system. Ag3PO4 catalyst has an excellent photocatalytic performance due to the high separation efficiency of electron and hole pairs. In the neutral pH solution, Ag3PO4 catalyst exhibited the best photoactivity under simulated sunlight. The photoinduced holes were considered to be the dominant active species in the photodegradation process.

A simple template-free hydrothermal method was employed to synthesize flower-shaped single-crystal rutile TiO2 hierarchical nanostructures without calcination process. Scanning electron microscope and transmission electron microscope images show that rutile TiO2 nanostructures with diameters of 1–1.5 μm are composed of nanorods with a wimble shape. The band gap of the as-prepared rutile TiO2 is about 3.02 eV by ultraviolet–visible absorption spectrum. The photocatalytic performance of the as-obtained samples as catalysts for Rhodamine B (RhB) degradation under simulated solar light was greatly enhanced with the assistance of a small amount of H2O2. In the H2O2-containing system, the as-prepared rutile TiO2 photocatalyst was more efficient in the photodegradation of RhB than commercial P25. The stability and recycle of the rutile TiO2/H2O2 system were also investigated.

Mesoporous TiO2 microspheres were prepared by a hydrothermal reaction and are characterized in this paper. Decoloration and mineralization during photodegradation of Orange II by mesoporous TiO2 at different pH values, formation of sulfate, relative luminosity to luminous bacteria and recycling experiments of the catalyst were studied. The FTIR results further suggested that the novel mesoporous TiO2 can not only decolor and mineralize dyes completely but also can be effectively reused several times. On the basis of the research, mesoporous TiO2 would be a promising photocatalyst for practical use.

A series of mesoporous titanium dioxide microspheres were calcined at various temperatures to improve their photocatalytic activity. The prepared catalysts were characterized by XRD, SEM, TEM, TG-DTA, UV−vis, and N2 adsorption−desorption measurements, and their photocatalytic performances were investigated by photooxidation of gaseous toluene. As the results revealed, calcination temperatures obviously influenced the surface morphology and photocatalytic activity of the mesoporous TiO2 microspheres. The noncalcined samples had a mesoporous structure of the anatase phase. The sample calcined at 400 °C showed a superior photocatalytic performance, which had a reaction rate constant 2-fold higher than that of P25. The enhanced photoreactivity is possibly due to the synergetic effects of the mesoporous structure and light-transmittance ability of the catalysts. Two new reaction intermediates were discovered as well, and a tentative degradation pathway was proposed.Keywords: mechanism; mesoporous adjustment; photocatalysis; reaction intermediates; titanium dioxide microspheres

This paper describes the fabrication of two different 3D mesoporous TiO2 microspheres via one-step solvothermal process without templates using different titanium sources. The resulting materials were characterized by XRD, FESEM, TEM, and nitrogen adsorption techniques. Their photodegradation of bisphenol A [2,2-bis(4-hydroxyphenyl)propane, BPA] in aqueous suspension was investigated under UV irradiation. The experimental results revealed that the photocatalytic effect of the two 3D mesoporous TiO2 microspheres was superior to the commercial P25 TiO2, and as-prepared samples as catalysts demonstrated that the smaller pore size it is, the higher the effective degradation for BPA is. Particular attention was paid to the identification of intermediates and analysis of photocatalytic degradation mechanism of BPA by HPLC-MS and HPLC-MS-MS. Five main intermediates were formed during photocatalytic degradation, and their evolution was discussed. On the basis of the evidence of oxidative intermediate formation, a detailed degradation pathway of BPA degradation by two mesoporous TiO2 microspheres photocatalysts are proposed.

The photocatalytic degradation of 17β-estradiol (E2), by Fenton like reaction was investigated as a function of E2 concentrations, organic co-solvents and co-existing estrogens, humic acid (HA) and other background anions. E2 degradation was effectively achieved by hydroxyl radicals that were generated in the heterogeneous photo-Fenton process. The degradation kinetics were fitted to Langmuir–Hinshelwood model with kr = 0.3140 µM/h and Kads = 2.2146L/µmol. The removal kinetics of E2 were initiated by a rapid decay and then followed by a much slower one in acetonitrile–water solutions while in methanol–water solutions they followed the first-kinetic model for the diffusion-control of hydroxyl radicals and competition between E2 and co-solvents. In addition, the lower level of co-existing substances did not significantly influence the oxidation efficiency of E2. The degradation rates of E2 were found to depend not only on the concentrations of hydrogen peroxide and iron content as reported before but also on pH, E2 concentrations and composition of co-solvents. Thus it is very important to look for the optimum conditions for the purpose of most efficiently eliminating E2 from drinking water.

Two-dimensional (2D) nanosheets directly grew into three-dimensional (3D) microspheres through a one-step solvothermal route under controlled conditions; during this procedure the decomposition of hexamethylenetetramine at temperatures higher than 120 °C provided OH− at the rate of good diffusion, and surfactants were used as templates to provide the growth sites and control the crystalline growth direction. By means of the Ostwald ripening process, precursor microspheres formed with narrowly distributed diameters, and then NiO 3D microspheres were obtained with further calcination at 300 °C for 2 h. NiO microspheres presented a high initial discharge capacity as anode materials in Li ion batteries, but degraded quickly during subsequent cycles, and further improvement in cyclic stability is still needed for practical application in Li ion batteries.

The morphology control of β-indium sulfide (β-In2S3) microspheres has been achieved through a one-step solvothermal route, by simply adjusting the combinations of two additives, n-butanol and Span80. The products show complex hierarchical structures assembled from nanoscaled building blocks. The morphology evolution can be realized on both outside (surface) and inside (hollow cavity) of the microsphere. Electrochemical measurements have shown that these In2S3 microspheres possess higher initial Li intercalation capacity than that of graphitic materials (372 mAh/g). It will be possible to improve the cyclic performances of the anode materials for their applications to practical batteries.

Nanostructured TiO2 with different hierarchical morphologies were synthesized via a warmly hydrothermal route. The properties of the products were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, N2 adsorption, UV–vis spectroscopy, etc. Two of the products, TiO2 1D nanorods (one-dimensional rutile TiO2 nanorods) and TiO2 3D0D microspheres (three-dimensional anatase TiO2 nanoparticle-assembled microspheres) exhibited superior photocatalytic effects on phenol degradation under UV illumination, compared with TiO2 3D1D microspheres (three-dimensional rutile TiO2 nanorods-assembled microspheres). Moreover, TiO2 3D0D was superior to TiO2 1D, as indicated by a 30% higher mineralization of dissolved phenol. Dihydroxybenze, 4,4′-dihydroxybiphenyl, benzoquinone, maleic anhydride, etc. were identified as the degradation intermediates. The excellent catalytic effect was attributed to the structural features of TiO2 1D nanorods and TiO2 3D0D microspheres, that is, a larger amount of surface active sites and a higher band gap energy resulted in more efficient decomposition of organic contaminants.

•Through a simple hydrothermal treatment to prepare mesoporous nanoplate TiO2/RGO composites.•The mesoporous nanoplate TiO2/RGO composites exhibit enhanced lithium storage properties.•This work is favorable to explore advanced TiO2-based nanocomposites as anode materials for LIBs with high power density.Mesoporous nanomaterial has been extensively studied in high-performance anode materials, because of their large electrolyte–electrode contact area, small volume change, high safety and enhanced specific capacity during discharge/charge process. Herein, we use titanium trichloride as Ti-sources and adjust the pH of solvent to successfully prepare mesoporous nanoplate TiO2 on reduced graphene oxide (RGO) nanosheets via two-step hydrothermal treatment. Benefiting from the unique structure, as-prepared mesoporous nanoplate TiO2/RGO composites present high reversible capacity and strong cycling stability (high capacity of ∼200 mA h g−1 at 1.2 C after 300 cycles) as anode materials for Li ion batteries (LIBs).

•Through a facile, room-temperature process to prepare NiSe2 nanoparticles.•NiSe2 nanoparticles exhibited good PCE as CEs for Pt-free DSSCs.•Grapheme as a dopant could promote the electrocatalytic activity of DSSCs.•NiSe2 + 6 wt% graphene CE exhibited better PCE compared with Pt CE.Metal selenides have been proposed as counter electrodes (CEs) to substitute for Pt in dye-sensitized solar cells (DSSCs) due to their good catalytic activity for the reduction of triiodide. In this paper, NiSe2 nanoparticles were synthesized by a facile, room-temperature process and used as the CEs. In order to further enhance the photovoltaic property, graphene was introduced by facile physical mixing. Eventually, with the assistance of graphene, NiSe2 + 6 wt% graphene CE exhibited better power conversion efficiency (PCE) compared with Pt CE.

Composites of TiO2–B nanorods and reduced graphene oxide (RGO) were prepared through a simple two-step hydrothermal process followed by subsequent heat treatment in argon. The obtained TiO2–B nanorods had a small size (∼10 nm diameter of the nanorod) and a uniform morphology. Importantly, the synergistic effect of RGO nanosheets and nanostructured TiO2—B leads to electrodes composed of the TiO2–B–RGO nanocomposites which exhibit excellent cycling stability and rate capability (260 mA h g−1 at 1 C and 200 mA h g−1 at 2 C after 300 cycles and 140 mA h g−1 at 20 C).

Through hybrid density functional theory, we computationally designed two-dimensional ZnO–GaN heterostructured nanosheets, and investigated their structural, electronic and optical properties. As a result of the type-II band alignment of ZnO and GaN, both bare (ZnO)m(GaN)n and hydrogenated H-(ZnO)m(GaN)n (m, n ≥ 3) nanosheets have band gaps below 3.0 eV with visible-light absorption accordingly, which is confirmed by computed optical properties. Also, photo-induced electrons and holes are directly separated and spatially confined in the ZnO and GaN regions, respectively, which is preferable for restraining ultrafast recombination of photo-excited e−–h+ pairs. Moreover, due to the perfect lattice matching of ZnO and GaN crystals, the heterostructured ZnO–GaN nanosheets have few crystal defects at the interfaces, which act as excitons' recombination centres. ZnO–GaN heterostructured nanosheets are promising high-performance materials for solar harvesting.

A simple and steerable method was adopted to synthesize well-distributed rutile TiO2 nanobundles on reduced graphene oxides through two-step hydrothermal methods. The rutile TiO2–RGO composites were used as the anode materials in lithium ion batteries for investigation, which had an original morphology and a reversible capacity of 300 mA h g−1 at 0.6 C and 200 mA h g−1 at 1.2 C after 500 cycles.

The photocatalytic degradation of 17β-estradiol (E2), by Fenton like reaction was investigated as a function of E2 concentrations, organic co-solvents and co-existing estrogens, humic acid (HA) and other background anions. E2 degradation was effectively achieved by hydroxyl radicals that were generated in the heterogeneous photo-Fenton process. The degradation kinetics were fitted to Langmuir–Hinshelwood model with kr = 0.3140 µM/h and Kads = 2.2146L/µmol. The removal kinetics of E2 were initiated by a rapid decay and then followed by a much slower one in acetonitrile–water solutions while in methanol–water solutions they followed the first-kinetic model for the diffusion-control of hydroxyl radicals and competition between E2 and co-solvents. In addition, the lower level of co-existing substances did not significantly influence the oxidation efficiency of E2. The degradation rates of E2 were found to depend not only on the concentrations of hydrogen peroxide and iron content as reported before but also on pH, E2 concentrations and composition of co-solvents. Thus it is very important to look for the optimum conditions for the purpose of most efficiently eliminating E2 from drinking water.

3D mesoporous BiOBr microspheres were fabricated via a facile, rapid and environmentally friendly one-step solvothermal process without using templates. The physiochemical properties of BiOBr were characterized by XRD, FESEM, TEM and nitrogen adsorption techniques. The photodegradation behaviors of bisphenol A (BPA) catalyzed by BiOBr were investigated under simulated solar light irradiation. The photocatalytic activities of the BiOBr were superior to that of commercial Degussa P25 TiO2. Particular attention was paid to the identification of intermediates and acute toxicity of photocatalytic degradation samples of BPA by GC–MS and bioluminescence bacteria, respectively. Deducing from the results, BiOBr can be a good kind of catalyst irradiated by visible light even under sunlight.

Hierarchical flower-like Nb2O5 microspheres have been prepared via a facile hydrothermal approach without any additives. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were employed to clarify the structure and morphology of the Nb2O5 microspheres. Structure and morphology evolution mechanisms have been proposed for the hierarchical structure in detail. During the symmetric Ostwald ripening, the resultants formed aggregates composed of two-dimensional nanoflakes as building blocks. Photocatalytic activity of the as-prepared Nb2O5 microspheres was evaluated by the photodegradation of Rhodamine B (RhB), and over 90% of RhB was degraded within 30 min under the irradiation of UV light. The as-prepared Nb2O5 exhibits higher photocatalytic activity than commercial Degussa P25. Moreover, Nb2O5 was tested as an anode material of lithium-ion batteries, which displayed high reversibility and excellent rate stability at a current density of 50 mA g−1.

Via density functional theory computation and experimental validation, we have compared the catalytic activities of different facets within Bi2S3, as counter-electrode (CE) materials for dye-sensitized solar cells (DSSCs). The (130) facet has the largest surface energy, the best electronic conductivity, and the highest position of conduction band minima, indicating the most effective electron transfer from CEs to I−3 and the highest catalytic activities of Bi2S3 with (130) facets. To testify the computations, we also synthesized flower-like Bi2S3 nanostructures with dominantly exposed (130) and (211) facets, respectively, and investigated their catalytic activities through impedance spectra, I–V curves and conversion efficiency tests. DSSCs with (130) and (211) faceted Bi2S3 CEs exhibited conversion efficiencies of 3.5% and 1.9%, respectively, which further confirmed the superiority of (130) facets within Bi2S3. The findings provide some clues for designing and applying low-cost Pt-free DSSC CE materials from inorganic nanostructures.

Mesoporous TiO2 microspheres were prepared by a hydrothermal reaction and are characterized in this paper. Decoloration and mineralization during photodegradation of Orange II by mesoporous TiO2 at different pH values, formation of sulfate, relative luminosity to luminous bacteria and recycling experiments of the catalyst were studied. The FTIR results further suggested that the novel mesoporous TiO2 can not only decolor and mineralize dyes completely but also can be effectively reused several times. On the basis of the research, mesoporous TiO2 would be a promising photocatalyst for practical use.