ZnO, ZrO2, Fe2O3 and SnO2 are all typical metal oxide semiconductors that can be used as photocatalysts for the degradation of organic pollutants in water. In this contribution, we applied the technology of ultrasonic irradiation to modify the nanocrystals (NCs) of these metal oxide semiconductors, which facilitated the hydrolysis as well as the hydroxyl injection of these NCs, resulting in the disorder engineering around their crystal lattice. The disorder modification induced band gap narrowing, the enhancement of optical absorption and inhibited recombination of photo-generated charge carriers of each metal oxide semiconductor NC, through which was eventually achieved the better performance in photocatalysis of all these materials.

Through thermal decomposition of hybrid carbonate (Cu, Co)2(OH)2CO3 precursors synthesized by a simple carbonate-assisted hydrothermal method, porous hierarchical Co3O4/CuO composites with different ratios of Co to Cu were successfully fabricated. A cooperative self-assembly effect of different carbonates has been proposed to explain the formation of nanosheets assembled hierarchical (Cu, Co)2(OH)2CO3 precursor. Electrochemical lithium storage properties of all the composites are evaluated as anode materials for lithium-ion batteries. It is found that the ratio of Co to Cu plays a vital role in affecting the morphology, structure and subsequent electrochemical performance of the Co3O4/CuO composites. Owing to the superior porous hierarchical structure and synergistic lithium storage effect of both active electrode materials, the Co3O4/CuO composites demonstrate higher capacities and enhanced cycling stability compared to pure Co3O4 or CuO electrodes. The Co3O4/CuO composite (Co: Cu = 6: 1) electrode delivers a high reversible capacity of 1056 mAh g−1 at a current density of 200 mA g−1 for 500 cycles. With the superior electrochemical performance and easy preparation, the porous hierarchical Co3O4/CuO composites demonstrate promising application potential as anode materials for next generation high performance LIBs.

Disorder engineering on TiO2 nanocrystals (NCs) generates a nanocomposite with core–shell structure, which has been proven to achieve higher photocatalytic activity than the original TiO2 NCs. In this contribution, we engineered disorder layers around hydrothermally synthesized anatase NCs using the method of ultrasonic irradiation, obtaining anatase@amorphous TiO2 core–shell structure nanocomposites. The proportion of two phases (amorphism/anatase) in the nanocomposites was regulated by controlling the average diameter of the anatase NCs and the properties of the nanocomposites would change accordingly. The structure and photocatalytic activity of each sample were carefully compared to find out the appropriate synthesis conditions to obtain the optimal nanocomposite.

Hollow TiO2 microspheres (HTS) were synthesized via a new one-pot template-free method, which exhibited amazing structure stability even at high temperature calcinations of 800 °C. The formation mechanism study indicates that the growth of HTS is like the inside-out Ostwald ripening process. The resultant HTS possess a fine porous structure and the surface area is high up to 86.5 m2 g−1. As a new functional material in the DSSC application, HTS simultaneously offer incompatible features such as a high specific surface area and a pronounced light-scattering effect, and hence an energy conversion efficiency of 6.3% can be archived directly utilizing HTS as photo-anodes. If fabricated into the bilayer structure by introducing HTS as the light scattering layer, the overall conversion efficiency can be further improved to 7.3%. The successful synthesis of these novel photo-anodes opens up a new way to improve the performance of DSSCs.

Porous, hierarchical CuO microspheres (MSs) have been successfully synthesized through a facile, surfactant-free carbonate-assisted hydrothermal method. A growth mechanism based on self-aggregation and decomposition of precursor Cu2(OH)2CO3 nanoparticles and Ostwald ripening under hydrothermal conditions is proposed to explain the formation of CuO MSs. Then the CuO MSs are encapsulated with GO through engineering the ionic strength in solution and applied as anode materials for lithium ion batteries, which demonstrates that CuO/GO exhibits significant improvements over the bare CuO MSs. It can deliver a high reversible capacity of 500 mA h g−1 after 500 cycles, with 80% capacity retention of the second reversible capacity (625.8 mA h g−1) at a current density of 0.5C. This is much higher than 233.5 mA h g−1 of the bare CuO MSs at the same rate. Such significantly enhanced electrochemical performance of the CuO/GO hybrid can be attributed to the synergistic effect of successful integration of the CuO MSs with the highly conductive and flexible GO sheets. This study demonstrates that facile structural tuning of the metal oxide in combination with advantageous carbon materials is a promising way to fabricate anodes for high-performance lithium-ion batteries.

We successfully synthesized sulfur particles with a bowl-like structure and wrapped them in graphene oxide (GO) via a simple method. The GO-wrapped bowl-like sulfur composite (GO-BS) with void space inside was used as cathode material of Li–S batteries, which realized the protection of active material and tolerance of volumetric expansion.

In this study, we have demonstrated coordination-driven self-assembly between Fe3O4 and graphene sheets under a hydrothermal condition for the simple in situ synthesis of a 3D Fe3O4–graphene hybrid architecture (Fe3O4/G). Fine hierarchical Fe3O4 spheres were homogeneously dispersed and embedded in an interconnected mesoporous framework of graphene sheets. It can be noted that the critical concentration of GO assembly decreased dramatically during the self-assembly of Fe3O4, indicating the coordination-driven self-assembly between Fe3O4 and GO. When evaluated as an anode material for LIBs, the Fe3O4/G hybrid framework demonstrates a high reversible capacity of 1164 mA h g−1 over 500 cycles at a current density of 500 mA g−1 and a remarkable rate capability. The superior electrochemical performance is attributed to a strong adhesion force and synergistic effect between Fe3O4 and graphene sheets as well as formation of a 3D interconnected hybrid framework, which offers enhanced kinetics towards electrochemical reactions with lithium ions and provides space for alleviating the huge volume expansion that occurs during charge–discharge cycles.

Different CuO nanostructures have been successfully synthesized through changing the drying medium of Cu(OH)2 nanorods precursors. Herein, Cu(OH)2 nanorods precursors were first prepared through a simple precipitation method. When H2O was chosen as the drying medium at 80 °C, 2D leaf-like CuO nanostructures were obtained. While dried in ethanol 1D Cu(OH)2 nanorods were obtained. With post-annealing, porous CuO nanoleaves and nanocrystalline-assembled CuO nanorods were successfully synthesized, respectively, which have been applied to lithium batteries as anode materials and influence of different nanostructures on the electrochemical properties have been investigated. Fortunately, both novel nanostructured CuO successfully displayed high capacity and excellent cycling stability, and porous CuO nanoleaves can exhibit a reversible capacity of 633 mA h g−1 and 576 mA h g−1 after 100 and 150 discharge–charge cycles at 67.4 mA g−1, which is superior to that of CuO nanoleaves without post-annealing. These results may provide valuable insights for the industrialization and development of new nanostructured anodes for next-generation high-performance lithium-ion batteries.

In this article, we report a new route to synthesize octahedral anatase mesocrystals (MCs), polycrystals (PCs) and single crystals (SCs) in the TiCl4–CH3COOH system just by tuning the reaction time and Ti-source concentration. Owing to the unique structures constructed from crystallographically oriented nanocrystals, MCs offer larger specific surface area than SCs and more effective electron transport compared with PCs. As anticipated, MCs show the highest photocatalytic activity in the degradation of methylene blue. MCs also demonstrate excellent cycle stability and renewable capability, and the photocatalytic efficiency still remains up to 90% even after five cycles. The designed fabrication of mesocrystals provides an attractive and effective route for improving the performances of semiconductor photocatalysts.

•Colloid chemistry method is used to prepare hydrated Na2O–B2O3–SiO2 glass.•Sodium silicate solution and H3BO3 used as precursor and the source of boron•The hydrated Na2O–B2O3–SiO2 glass has a relatively good chemical durability.•Tg of the hydrated glass increases with the decrease of the water content.•The hydrated glass powder can be transformed into a lightweight insulating board.In this paper, the hydrated Na2O–B2O3–SiO2 glass was prepared by colloid chemistry method, sodium silicate solution and boric acid as raw materials. The high viscosity transparent Na2O–B2O3–SiO2 colloid was drawn from the solution in the course of mixing, after drying in the oven at 60–200 °C for 24 h, the hard and transparent hydrated glass was obtained. The effect of drying temperature and B2O3 content was studied. The phase composition and thermal parameters were characterized by means of X-ray diffraction and thermal analysis. It was found that the temperature of glass transition (Tg) of this kind of glass increased along with the increase of the drying temperature and the durability of this glass increased with B2O3 content. The hydrated Na2O–B2O3–SiO2 glass could be dried to give amorphous solids, so it might have broad application prospects in the lightweight thermal insulation material field.

The hydrogenation on unmodified TiO2 to create disordered layers on the surface of anatase nanocrystals (NCs) in order to enhance the photocatalytic activity of TiO2 has been widely investigated in recent years. In this contribution, we prepared hydroxylated and N-doped anatase by controlling the degree of disorder of TiO2 derived from amorphous hydrate through a traditional pathway of heat treatment, which induced various colours in appearance and outstanding photocatalytic activities. The traditional method by heating to prepare hydroxylated TiO2 in this work is a reverse route compared to the pathway by hydrogenation, which opens opportunites for the modification of nano-dimension semiconductors derived from amorphous hydrates.

•A novel architecture of 3D carbon framework to encapsulate ZnO nanocrystals was prepared.•The ZnO@C exhibits ultralong cycle life and high specific capacity when was used as anode.•The in situ carbonization leads to a strong connection between the carbon and ZnO.In this paper we report a novel architecture of three-dimension (3D) carbon framework to encapsulate tetrahedron ZnO nanocrystals that serves as an anode material for lithium-ion batteries (LIBs). The ZnO@C composites are prepared via a simple internal-reflux method combined with subsequent calcination in argon. The amorphous carbon is formed on the surface of the ZnO crystals by in situ carbonization of the surfactant, which leads to a strong connection between the carbon framework and the active materials and guarantees faster charge transfer on the electrode. The ZnO crystal calcined at 500°C (ZnO@C-5) possesses regular tetrahedron shape with a side length of 150-200 nm and all of them are uniformly anchored among the network of amorphous carbon. The developed ZnO@C structures not only improve the electronic conductivity of the electrode, but they also offer a larger volume expansion of ZnO during cycling. As a result, the ZnO@C-5 demonstrates a higher reversible capacity, ultralong cycle life and better rate capability than that of the ZnO@C-7 and pure ZnO crystals. After 300 cycles, the ZnO@C-5 demonstrates a high capacity of 518 mAhg−1 at a current density of 110.7 mAg−1. Moreover, this simple approach prepared the 3D composites architecture could shed light on the design and synthesis of other transition metal oxides for energy storage.

A hydrothermal precursor was first obtained by isopropyl titanate reacting with tetramethylammonium hydroxide (TMAOH), which acts as a source of nitrogen and carbon. A facile post-thermal treatment was employed to enhance the crystallinity and visible light photocatalytic activity of the as-prepared precursor. The resulting products of post-thermal treatment between 200 °C and 700 °C display different colours from brown to white. Black N-doped TiO2 nanoparticles modified with carbon (denoted as N-TiO2/C) were obtained at 300 °C, while yellow N-doped TiO2 nanoparticles (denoted as N-TiO2) were obtained at 500 °C. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) were applied to characterize N-TiO2/C, N-TiO2 and the evolution process during thermal treatment. The results show that for both N-TiO2/C and N-TiO2, nitrogen was doped into the lattice, thus narrowing the band gap and increasing the absorption in the visible light region. Moreover, for N-TiO2/C, the carbon species modified on the surface and between the nanocrystals enhanced the visible light harvesting and increased the adsorption of the dye in the photodegradation measurement. The photocatalytic performance under visible light irradiation is N-TiO2/C > N-TiO2 > undoped TiO2.

Oriented attachment, as aggregation based crystallization, is one of the most promising approaches in designing novel nanostructures. A two-step solvothermal method is reported in this work to synthesize TiO2 nanochains with one-dimensional single-crystalline nature, which is formed by oriented attachment and with tunable length. We achieved selectively reducing the stereo-hindrance effect at (001) surfaces and making the processes of Ostwald ripening and oriented attachment asynchronous. By virtue of the 1D single crystalline nature, the conversion efficiency of dye-sensitized solar cell was improved. This approach opens the door for controllable oriented attachment, and it is meaningful for designing novel nanoarchitectures.

In this article, TiO2 has been successfully fa in the Ti(SO4)2–CH3COOH system via a simple hydrothermal method. The formation mechanism of the TiO2 hierarchical nanostructures was also investigated in detail, which involved the complex reaction between Ti(SO4)2 and CH3COOH, hydrolysis of the complex, nucleation and self-assembly of TiO2 nanocrystals and anisotropic growth of these subunits. SO42− plays an important role in the self-assembly of subunits. In addition, controllable synthesis of TiO2 hierarchical nanostructures with tunable size can be realized just by changing experimental parameters, such as reaction time or Ti(SO4)2 concentration. When used as the anode in lithium ion batteries, these TiO2 hierarchical nanostructures present much higher specific capacity and better rate performances than TiO2 nanoparticles, which are attributed to the stability of the secondary-structure during the charge and discharge processes.

Hierarchical TiO2 sub-microspheres (SMSs) constructed from anatase TiO2 nanorods (NRs) are prepared by a simple bottom-up self-assembly approach. The assembly process is achieved by dissolving the oleic acid-coated NRs into cyclohexane solution and refluxing at 80 °C without any other surfactants or complex steps. The TiO2–C nanocomposite is synthesized by carbonization and the amorphous carbon layer is formed in situ on the surface of the nanorods, which could improve the conductivity of the electrode. The hierarchical structures of TiO2–C SMSs are verified by BET test results, which shows a typical type-IV isotherm curve and the pore volume of the SMSs is approximately three times that of the NRs, indicating the formation of three-dimensional mesoporous networks. As a Li-ion battery anode material, the assembled TiO2–C SMSs exhibit better electrochemical performance with enhanced capacity, greater cyclic stability and better rate performance compared to those of unassembled NRs or P25. Moreover, any other oleic acid-coated nanocrystals could be prepared by adopting this bottom-up strategy.

We report a room-temperature, facile and scalable strategy for the synthesis of Mn3O4 nanosheet/graphene nanocomposites. An important characteristic of these Mn3O4 nanosheets is their mesoporous nature and they have mesopores which are ∼4 nm in size. Such nanocomposites exhibit a high performance in lithium-ion batteries by virtue of this advantageous structural feature.

Spherical anatase mesocrystals have been successfully prepared in an acetic acid–tetrabutyl titanate–benzoic acid system via a facile solvothermal method. Based on the results of time-dependent experiments, a growth process is proposed for the spherical mesocrystals, which includes the formation of flower-like intermediates, the hydrolysis of these intermediates, and the precipitation and self-assembly of TiO2 nanocrystals. Benzoic acid plays an important role in the formation of the spherical morphology. Well-defined spherical anatase mesocrystals can be obtained only when the benzoic acid content is >4.5 g. As a result of their unique architecture (high crystallinity and a large specific surface area), the Li ion storage capabilities of these spherical mesocrystals were also investigated. The first discharge capacity is 314.5 mA h g−1 and the corresponding charge capacity is 224.3 mA h g−1, leading to a Coulombic efficiency of 71.3% at 0.2 C. Even under high current densities, such as 2 and 5 C, this anode material retains a good cycling stability and very high specific capacity.

•Anatase TiO2 nanorods were prepared via a soft internal-reflux approach.•The TiO2/C composites with high surface area and mesoporous structure were formed by in situ carbonization of the surfactant.•The TiO2/C nanorods exhibited a high reversible capacity and improved capacity retention.Anatase TiO2/C composites nanorods were prepared via a simple internal-reflux approach under atmospheric pressure and subsequent carbonization. The oleic acid, which was used as the surfactant and carbon source, played an important role in synthesis and carbonization process. The TiO2/C nanorods prepared have high surface area and mesoporous structure, which are ascribed to the small diameter (2–4 nm) of nanorods and in situ formation of amorphous carbon, and both of those characters can improve the electrochemical property of TiO2/C electrode. The nanorods exhibit a high reversible capacity and improved capacity retention. The initial discharge capacity of TiO2/C composites is 411 mAhg−1 and still remains about 164.2 mAhg−1 after 50 cycles at a current of 177 mAg−1, when used as anode materials for lithium ion batteries.

Introduced by sodium fluoride, we employed fluorine ions as novel morphology control agents and synthesized highly crystalline TiO2 truncated tetragonal nanobipyramids enclosed by {001} and {101} facets via a facile microemulsion method. By investigating the influence of halogens ions such as fluorine, chloride, and bromine on the morphology of TiO2 nanocrystals, we demonstrate that the rate of crystal growth could be promoted by fluorine and that the selective absorption of fluorine onto the surface of nanoparticles would alter the relative surface free energies of {001} and {101}, eventually controlling the ration of {001} facets to total surface area. Additionally, chainlike 1-D TiO2 nanostructures aligned from nanobipyramids were generated via the mechanism of oriented attachment at a relatively high temperature. The driving force for shape evolution is reducing the high surface free energy. The photocatalytic properties were performance by the photodegradation of methylene blue. This “greener” and versatile synthetic strategy may provide an attractive and effective route for shape-controlling of inorganic nanoparticles.

Nano-structured cubic SnO2 crystalines were successfully synthesized through solvothermal route. The obtained products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and high resolution TEM (HRTEM). The study showed that, the SnO2 particles were rutile structured and almost uniformly cube shaped crystals in quantum size (3–8 nm). Self-assembly behavior of the cubic SnO2 quantum dots was also observed. The synthesis process can be defined as an nonhydrolysis (NH) hydroxylation reaction provided by the amide elimination of carboxylated precursors. The formation of cubic morphology of SnO2 can be ascribed to the mild reaction featured by high nucleation rate and low growth rate, surface energy difference of the crystallographic facets of SnO2 and the passivation effect of the starting material-dodecylamine which drastically reduced the dipole interation. The selfassembly of the cubic SnO2 quantum dots was driven by van der Waals force and capillary force.

Highly crystalline orthorhombic Bi2WO6 powders were hydrothermally synthesized from aqueous solutions of Na2WO4 · 2H2O and Bi (NO3)3 · 5H2O over a wide range of pH. The effect of pH on morphologies, sizes and properties of the Bi2WO6 crystals was investigated. The band gaps of the as-prepared Bi2WO6 were determined from the onset of the absorption edge of UV-vis diffuse reflectance spectra. The methyl orange photodegradation was employed as a probe reaction to test the photocatalytic activity of the as-prepared samples under visible light irradiation. The photocatalytic activities of methyl orange degradation under visible light irradiation are strongly dependent on the pH used in the synthesis. The highest efficiency is observed at pH=7.

A push-pull thiazolylazo chromophore and alkoxysilane-terminated chromophore have been synthesized. Their structures were verified by elemental analysis, FTIR, UV–Visible spectra and 1H NMR. Followed by a hydrolysis and copolymerization process of the alkoxysilane with poly(3-(trimethoxysilyl)propyl methacrylate) (PTMSPM), transparent hybrid films were obtained by spin-coating. From TGA thermogram the initial decomposition temperature of the hybrid film was determined to be 231 °C. The molecular hyperpolarizability of thiazolylazo chromophore was evaluated by solvatochromic method and the nonlinear optical coefficient value of the hybrid film was also calculated to be 56.8 pm/V by second harmonic generation (SHG) measurements. The poled film exhibits fairly high stability of optical nonlinearity in depoling experiment, implying its suitability for device applications.

The Eu2+ and Dy3+ co-activated Ca–Sr feldspar solid solution compounds, (Ca0.98−xSrx)Al2Si2O8:Eu0.01,Dy0.01 (x=0–0.98x=0–0.98), have been prepared by solid-state reaction in weak reductive atmosphere. The fluorescence spectra showed that the emission peaks of these phosphors shifts to shorter wavelength with an increase of Sr2+ solid solution quantity and correspondingly the afterglow color changes from blue to purple. All the changes can be attributed to the various crystal fields around Eu2+ ions. The afterglow with special short wavelength in near ultraviolet region can be obtained by adjusting the host chemical composition.

Various coumarin dyes are co-doped with perylene red (P-red) and pyrromethene 567 (PM567) into vinyltriethoxysilane-derived solid media, respectively. Energy transfer among laser dyes has been observed, and the effect of coumarin dye concentration on the laser properties has been investigated. With the presence of coumarin dye and pyrromethene 567, enhanced laser performances based on energy transfer of perylene red have been exhibited. The laser efficiency can be improved by two-fold and broad tunable range as wide as 80 nm can be achieved. At the pump intensity of 1.0 J/cm2, the laser output of co-doping perylene red decreases less than 30% after 30,000 pulses.

Eu2+ and Dy3+ co-activated CaAl2Si2O8-based long afterglow phosphor was firstly synthesized by solid state reaction. The phosphor emits a visible blue light under UV excitation and the blue afterglow lasts about 1 h in the dark. The phase-forming process of the phosphor was studied by means of differential thermal analysis (DTA) and X-ray diffraction (XRD) methods. The phosphor forms the final anorthite single-phase at about 1200 °C. The fluorescence spectra show that the excitation and emission spectra are both broadband and the emission peak is at 440 nm ascribed to the typical 4f7→4f 65d transition of Eu2+. The decay curves of afterglow indicate that the phosphor has a long afterglow feature and Dy3+ ions play an important role in prolonging the afterglow.

•Disorder modification on TiO2 nanocrystals through ultrasonic irradiation.•The theory of this method was hydroxyl injection into crystal lattices.•Degree of disorder could be controlled by ultrasonic time and pH value.•Optical absorption improvement and band-gap narrowing were achieved.•Photocatalytic activity of disordered TiO2 could be 2.33 times than P25 NCs.Disorder modification of TiO2 nanocrystals (NCs) has been proved to enhance the photocatalytic activity through surface defects and band-gap narrowing. In this contribution, we used a facile way of ultrasonic irradiation to induce the hydroxyls injection into TiO2 (P25) crystal lattice, which obtained disordered TiO2 NCs. In order to improve the degree of ultrasonic-induced disorder, extension of ultrasonic time or increasing alkalinity was necessary, which continuously regulated the energy band structure of TiO2 and could at most improve the solar-driven photocatalytic activity for 2.33 times than original P25 NCs.Ultrasonic irradiation induced disorder modification on TiO2 nanocrystals through hydroxyls injection, which caused the band-gap narrowing and the optical absorption improvement, resulting in the deeper color in appearance and the enhancement of solar-driven photocatalytic activity. The extension of ultrasonic time and increasing of pH value in reaction was more beneficial to the properties of disordered TiO2 NCs.

The hydrogenation on unmodified TiO2 to create disordered layers on the surface of anatase nanocrystals (NCs) in order to enhance the photocatalytic activity of TiO2 has been widely investigated in recent years. In this contribution, we prepared hydroxylated and N-doped anatase by controlling the degree of disorder of TiO2 derived from amorphous hydrate through a traditional pathway of heat treatment, which induced various colours in appearance and outstanding photocatalytic activities. The traditional method by heating to prepare hydroxylated TiO2 in this work is a reverse route compared to the pathway by hydrogenation, which opens opportunites for the modification of nano-dimension semiconductors derived from amorphous hydrates.

A hydrothermal precursor was first obtained by isopropyl titanate reacting with tetramethylammonium hydroxide (TMAOH), which acts as a source of nitrogen and carbon. A facile post-thermal treatment was employed to enhance the crystallinity and visible light photocatalytic activity of the as-prepared precursor. The resulting products of post-thermal treatment between 200 °C and 700 °C display different colours from brown to white. Black N-doped TiO2 nanoparticles modified with carbon (denoted as N-TiO2/C) were obtained at 300 °C, while yellow N-doped TiO2 nanoparticles (denoted as N-TiO2) were obtained at 500 °C. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) were applied to characterize N-TiO2/C, N-TiO2 and the evolution process during thermal treatment. The results show that for both N-TiO2/C and N-TiO2, nitrogen was doped into the lattice, thus narrowing the band gap and increasing the absorption in the visible light region. Moreover, for N-TiO2/C, the carbon species modified on the surface and between the nanocrystals enhanced the visible light harvesting and increased the adsorption of the dye in the photodegradation measurement. The photocatalytic performance under visible light irradiation is N-TiO2/C > N-TiO2 > undoped TiO2.