There is a growing body of antibiotics which are accumulated after usage by humans and animals for health reasons in the environment. Here, a 3D CeO2/RGO composite was obtained by using hydrothermal self-assembly synthesis method and in-situ deposition method. 3D CeO2/RGO composite was used firstly as cathode for efficient degradation of antimicrobial agent ciprofloxacin (CIP) in electro-Fenton system. The obtained composite was characterized by XRD, SEM, BET, TEM, HPLC-MS, CV and EIS. Synergistic effects from the electrosorption property of CIP on 3D CeO2/RGO and the electrocatalytic activity of CeO2 and the strong oxidizing property of hydroxyl radical (·OH) from electro-generated H2O2 in situ promote to reach about 100% efficient degradation of CIP. With the hydrothermal reaction time of 8 h and a current of 400 mA, about 100% antibiotics can be cleaned, and 91% TOC can be removed after 6.5 h at the experiment condition of pH = 3 and 0.1 mmol·L− 1 Fe2 + in 0.05 mol·L− 1 Na2SO4 solution. 3D CeO2/RGO composite can be used effectively as cathode in the electro-Fenton treatment for the deep degradation of CIP.

•Mo modified Mo(x)-MnOx catalysts were prepared for NH3-SCR removal of NOx.•Mo(2)-MnOx exhibited nearly 100% NOx conversion from 150 °C to 350 °C.•They have more Mn4+, surface adsorbed oxygen and Brønsted acid sitesA series of novel Mo modified Mo(x)-MnOx catalysts were prepared by co-precipitation and used for NH3-SCR removal of NOx at low temperatures, which were characterized by XRD, BET, TEM, H2-TPR, NH3-TPD, XPS and in situ DRIFT. It can be found that the addition of Mo species could induce the granular crystals transformed to the oblong-shaped nanorods, then BET surface area was obviously increased. Among the tested catalysts with different doping ratio, Mo(2)-MnOx exhibited nearly 100% NOx conversion from 150 °C to 350 °C with a gas hourly space velocity of 50000 h−1, meanwhile, better H2O resistance performance could also be found on Mo(2)-MnOx catalyst. These were due to its higher Mn4+ content, abundant surface adsorbed oxygen (Oα) and more acid sites based on H2-TPR, NH3-TPD, XPS and in situ DRIFT. Moreover, these preferable features could be correlated with the addition of Mo species by contrast with pure MnOx.Download high-res image (302KB)Download full-size image

Carbon felt (CF) was modified by CexA1−xO2 (A = Zr, Cu and Ni) and the role of these CexA1−xO2/CF (A = Zr, Cu and Ni) cathode materials in the oxidative degradation of antibiotic ciprofloxacin (CIP) was investigated in the electro-Fenton system. SEM, BET, TEM, XPS, TOC, HPLC-MS, CV and EIS were used to understand the characteristics of these cathode materials. The CIP degradation efficiency of the CexA1−xO2/CF (A = Zr, Cu and Ni) cathode was better than that of pure CF, and 2.0 wt% Ce0.75Zr0.25O2/CF was the most effective cathode material for degradation of CIP. It reached 100% degradation efficiency of CIP after 1 h and almost total mineralization (97.45%) after 6 h, owing to synergistic effects from the predominant role of homogeneous ˙OH produced electrocatalytically through the Fenton reaction of Fe2+ and H2O2 and heterogeneous ˙OH produced via the Fenton-like reaction of Ce3+ and H2O2 and the electrocatalytic activity of Ce0.75Zr0.25O2 composite and the strong electrosorption of carbon felt. A possible path of CIP degradation was proposed in the paper.

•The synthesized photocatalysts exhibited outstandingly enhanced photocatalytic disinfection efficiency.•A number of live bacteria could be completely inactivated with Ag2WO4(5%)/g-C3N4 (100 μg/mL) after 90 min.•The high disinfection efficiency is due to the synergetic effect between g-C3N4 and Ag2WO4.Ag2WO4/g-C3N4 composite photocatalyst was synthesized by polymerization of thiourea and ammonia chloride combined with the deposition-precipitation method, which was applied as an efficient visible-light driven photocatalyst for inactivating Escherichia coli (E. coli). The physicochemical properties of these photocatalysts were systematically characterized by various techniques such as SEM, TEM, XRD, FT-IR, BET, UV–vis DRS and PL. The synthesized photocatalysts exhibited outstandingly enhanced photocatalytic disinfection efficiency compared with that of pure g-C3N4 and Ag2WO4 under visible light. Furthermore, the optimal mass ratio of the Ag2WO4 to g-C3N4 was 5 wt%, and a number of live bacteria could be completely inactivated with Ag2WO4(5%)/g-C3N4 (100 μg/mL) after 90 min under visible light irradiation. The high disinfection efficiency is due to the synergetic effect between g-C3N4 and Ag2WO4, including a good distribution of Ag2WO4 particles on the surface of g-C3N4 and an improved separation rate of photogenerated electron-hole pairs. The enhanced disinfection mechanism was also investigated using photogenerated current densities and electrochemical impedance spectroscopy (EIS). Considering the bulk availability and excellent disinfection activity of Ag2WO4/g-C3N4 composite, it is a promising solar-driven photocatalyst for cleaning the microbial contaminated water.Download high-res image (121KB)Download full-size image

Mn2O3-doped Fe2O3 hexagonal microsheets were prepared for the low-temperature selective catalytic reduction (SCR) of NO with NH3. These hexagonal microsheets were characterized by SEM, TEM, XRD, BET, XPS, NH3-TPD, H2-TPR, and in situ DRIFT and were shown to exhibit a considerable uniform hexagonal microsheet structure and excellent low temperature SCR efficiency. When doped with different Mn molar ratios, Mn2O3 was detected in the Fe2O3 hexagonal microsheets based on the XRD results without the presence of other MnOX species. In addition, the hexagonal microsheets with a Mn/Fe molar ratio of 0.2 showed the best SCR removal performance among the materials, where a 98% NO conversion ratio at 200 °C at a space velocity of 30 000 h–1 was obtained. Meanwhile, excellent tolerances to H2O and SO2, as well as high thermal stability, were obtained in Mn2O3-doped Fe2O3 hexagonal microsheets. Moreover, on the basis of the XPS and in situ DRIFT results, it can be suggested that coupled Mn2O3 nanocrystals played a key role at low temperatures and produced a possible redox reaction mechanism in the SCR process.Keywords: hexagonal microsheets; low temperature; mechanism; Mn2O3-doped Fe2O3; SCR

A series of novel Mo doped CeO2 hollow microspheres have been successfully synthesized using carbon microspheres as templates, which were characterized by XRD, SEM, TEM, BET and used to selective catalytic reduction (SCR) of NOx with ammonia at lower temperature. Compared with pure CeO2 hollow microspheres, Mo doped CeO2 hollow microspheres showed a better catalytic performance from 200–400 °C. The optimal molar ratios of Mo/Ce and surface active sites to remove NOx were also investigated, which can significantly affect the catalytic performances. Among all the hollow microspheres with different molybdenum doping ratios, the obtained CeMo(0.3) hollow microspheres showed not only the best SCR performance at lower temperature but also excellent stability and H2O resistance, which was attributed to the higher Brønsted acid sites and reasonable Ce3+ content and chemisorbed oxygen species, and the synergic effect between CeO2 and MoO3 based on the XPS, NH3-TPD, H2-TPR and in situ DRIFTS results. Additionally, according to the reactivity of adsorbed NH3 and NOx species based on in situ DRIFTS, the excellent low-temperature NH3-SCR activity of CeMo(0.3) hollow microspheres was resulted from the reactivity of the more active NH4+ ions with gaseous NO2 molecules (i.e., the “fast SCR” reaction).

A series of MnO2 doped Fe2O3 hollow nanofibers with different Mn/Fe molar ratios were successfully synthesized by the electrospinning method for the low temperature selective catalytic reduction (SCR) of NO with NH3 in the presence of excess O2. The SEM and TEM images showed obvious hollow tubular structure of electrospun nanofibers. The hollow nanofibers with Mn/Fe molar ratio of 0.15 exhibited the highest catalytic activity, nearly 100% of NO conversion from 150 to 300 °C, among the catalysts investigated. The TPR, XPS and in situ FTIR results revealed that Mn4+ was the main active species for SCR reaction, and the addition of Mn species enhanced the surface concentration and acidity of Lewis acid sites.

Reduced graphene oxide coated polyurethane (rGPU) sponges were fabricated by a facile method. The structure and properties of these rGPU sponges were characterized by Fourier transform infrared spectroscopy, thermal gravimetric analysis, X-ray diffraction, and scanning electron microscopy. The rGPU sponges are hydrophobic and oleophilic and show extremely high absorption for organic liquids. For all the organic liquids tested, the absorption capacities were higher than 80 g g–1 and 160 g g–1 (the highest value) was achieved for chloroform. In addition, the absorption capacity of the rGPU sponge did not deteriorate after it was reused 50 times, so the rGPU sponge has excellent recyclability.Keywords: hydrophobic; oil absorption; oleophilic; polyurethane sponge; recyclability; reduced graphene oxide;

Microelectrode is firstly introduced into the research of vesicle formation. Carbon fibers are firstly applied as electrodes to construct vesicles by using electroformation method. Based on the superior electrode characteristics of carbon fiber, giant vesicles (GVs) of egg phosphatidylcholine (EggPC) were rapidly constructed after applying an AC electric field for 15-20 min. Study found that the carbon fiber is an excellent and efficient electrode for the electroformation of GVs. GVs are good drug carriers and represent the simple model systems of biological membranes. Due to the minisize of the carbon fiber electrode, GVs can be electroformed in the environment of a living body, which is expected to be in situ construction of artificial cell, drug delivery, and controlling release.Highlights► Carbon fibers are firstly applied as electrodes to construct vesicles. ► Vesicles were rapidly constructed after applying AC electric field for 15–20 min. ► Liberate the formation of vesicles from the restriction of conventional electrode

Mesoporous Fe2O3-doped TiO2 nanostructured fibers were fabricated through electrospinning the relevant gel precursor. The prepared fibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and surface analysis, respectively. The photocatalytic activity of these mesoporous composite fibers was evaluated by photocatalytic degradation of methylene blue (MB) in water under UV irradiation. Compared with different types of photocatalysts, the 1% Fe2O3-doped TiO2 fibers exhibited super photocatalytic activity.Graphical abstractMesoporous Fe2O3-doped TiO2 nanostructured fibers were fabricated through electrospinning relevant gel precursors. Compared with different types of photocatalysts, the 1% Fe2O3-doped TiO2 fibers exhibited higher photocatalytic activity.Research highlights► Long mesoporous Fe2O3-doped TiO2 fibers with high surface areas were prepared by the sol–gel and electrospinning techniques. ► The mesoporous fibers were as long as 20 cm with diameters of 0.5–2 μm. ► N2 adsorption–desorption isotherms gave a BET surface area of 200–228 m2/g and average pore size of 6.5 nm. ► These mesoporous 1% Fe2O3-doped TiO2 fibers showed higher photocatalytic activity toward decomposition of MB than many other catalysts. ► In addition, the long composite fibers can be conveniently fixed and reclaimed so that they are good candidates for photocatalytic applications.

A typical salt-free zero-charged catanionic system was constructed by mixing C14H29N+(CH3)3OH-C14H29N+(CH3)3OH- (TTAOH) and lauric acid (LA). The electrochemical behaviors of K4[Fe(CN)6] in salt-free TTAOH/LA micelle phase and vesicle phase solutions at glassy carbon (GC) electrode at different scan rate were obtained. A pair of well-defined redox peaks of [Fe(CN)6]3-/4-[Fe(CN)6]3-/4- is observed in TTAOH/LA vesicular solution with ΔEp = 61 mV at the scan rate of 0.001 V/s. Compared to the electrochemistry of K4[Fe(CN)6] in aqueous solution and TTAOH/LA micellar aqueous solution, the reversibility of [Fe(CN)6]3-/4-[Fe(CN)6]3-/4- is significantly improved in TTAOH/LA vesicular aqueous solution.

A series of MnO2 doped Fe2O3 hollow nanofibers with different Mn/Fe molar ratios were successfully synthesized by the electrospinning method for the low temperature selective catalytic reduction (SCR) of NO with NH3 in the presence of excess O2. The SEM and TEM images showed obvious hollow tubular structure of electrospun nanofibers. The hollow nanofibers with Mn/Fe molar ratio of 0.15 exhibited the highest catalytic activity, nearly 100% of NO conversion from 150 to 300 °C, among the catalysts investigated. The TPR, XPS and in situ FTIR results revealed that Mn4+ was the main active species for SCR reaction, and the addition of Mn species enhanced the surface concentration and acidity of Lewis acid sites.