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Metallic molybdenum sulfide (1T-MoS2) is considered as the most promising electrocatalyst for the acidic hydrogen evolution reaction (HER). Nevertheless, exploring a facile and effective approach for achieving high-purity 1T-MoS2 is still full of challenges. Herein, we demonstrate a two-dimensional material-assisted confined synthetic strategy, as an available method to construct and stabilize 1T-MoS2. During the hydrothermal process, the interaction between the N source and MoS2 is largely enhanced in a two-dimensional confined reactor, formed by reduced graphene oxides, successfully obtaining a high concentration of 90.1% of 1T-MoS2, named N-MoS2/rGO. The optimal N-MoS2/rGO nanosheets require a low overpotential (130 mV) to reach a current density of 10 mA·cm–2 and a low Tafel slope of 46.5 mV·dec–1. Additionally, they also exhibit high stability for at least 12 h in an acidic electrolyte maintaining 84.2% of the 1T-MoS2 phase. This work opens up an avenue to construct two-dimensional metastable materials for advanced catalysis. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: Ethanol is considered a better fuel than methanol in direct alcohol fuel cells because of the high energy density and low toxicity. Compared with noble metal catalysts, nickel‐based catalysts are much cheaper in price. However, present nickel‐based catalysts still surfer from some disadvantages such as low activity and high overpotential. In this paper, we show a new and high efficient nickel‐ based catalyst for ethanol oxidation. A layer of anodized nickel passivation film (Ni‐APF) was formed on the surface of nickel sheet by anodic oxidation method with carbon dots (CDs) as co‐catalyst. At the current density of 110 mA·cm−2, the potential for Ni‐APF/CDs was only 0.541 V (vs. Ag/AgCl), which was 18.8% lower than that of Ni‐APF. Low overpotential could reduce electrode thermal loss and increase output energy. Ni‐APF/CDs showed 144.4 mA∙cm−2 peak current density at peak potential 0.662 V (vs. Ag/AgCl), which was 31% higher than that of Ni‐APF (110.3 mA∙cm−2). In this system, CDs mainly function in the increase of charge‐transfer capacity and the promotion oxidation of carbonaceous intermediates. [ABSTRACT FROM AUTHOR]

Three technologies including carbon decomposition, seed decomposition and their combination are used for spent aluminum air battery electrolyte decomposition, and the particle size of aluminum hydroxide after decomposed phase, poor differential thermal weight change and surface morphology were analysized. The results show that the aluminum hydroxide produced by the carbon decomposition process has a large particle size and coarse particles and cannot be used as a flame retardant; The particle size and morphology of aluminum hydroxide prepared by the combined process of seed decomposition and seed decomposition and carbon separation meet the requirements of flame retardant aluminum hydroxide. In the preparation of aluminum hydroxide by the combination decomposition of seed and carbon, the decomposition rate was more than 90%, which was much higher than that of the seed and carbon separation process. [ABSTRACT FROM AUTHOR]

Thisstudy investigated how a natural sphalerite (NS) photocatalyst,under visible light irradiation, supports photocatalytic bacterialinactivation. This was done by comparing parent E.coliBW25113, and its two isogenic single-gene knock-outmutants, E. coliJW0797-1 (dps–mutant) and JW1721-1 (katE–mutant), where both dpsand KatEgenes are likely related to H2O2production. NS could inactivate approximately 5-, 7- and 7-log of E. coliBW25113, JW0797-1, and JW1721-1 within 6h irradiation, respectively. The two isogenic mutants were more susceptibleto photocatalysis than the parental strain because of their lack ofa defense system against H2O2oxidative stress.The ability of in situresultant H2O2to serve as a defense against photocatalytic inactivationwas also confirmed using scavenging experiments and partition systemexperiments. Studying catalase activity further revealed that in situH2O2played an important rolein these inactivation processes. The destruction of bacterial cellsfrom the cell envelope to the intracellular components was also observedusing field emission-scanning electron microscopy. Moreover, FT-IRwas used to monitor bacterial cell decomposition, key functional groupevolution, and bacterial cell structures. This is the first studyto investigate the photocatalytic inactivation mechanism of E. coliusing single-gene deletion mutants undervisible light irradiation. [ABSTRACT FROM AUTHOR]

BACKGROUND In this study, highly ordered titanium dioxide ( TiO2) nanotube arrays with tunable inner-diameter and morphology were synthesized by an anodizing method from titanium (Ti) foil by optimizing different preparation parameters, and acyclovir was degraded to test the photoelectrocatalytic activity of prepared nanotubes in a thin layer reactor. RESULTS The results indicated that anodization time, the concentrations of NH4F and HAc had significant effect on the surface morphology and inner-diameter of TiO2 nanotubes. Various morphologies including honeycomb films and nanotube arrays were obtained under given conditions. Photoelectrocatalysis showed higher degradation efficiency than that of photocatalysis or electrolysis due to TiO2 nanotubes regular nanotubular effectively reducing the recombination of photo-generated electron-hole pairs. The photoelectrochemical responses and degradation efficiencies of acyclovir were well related to the TiO2 crystallinity and morphology of TiO2 nanotube photoanodes. Regular nanotube array photoanodes displayed better crystallinity, higher photoelectrochemical response and higher photoelectrocatalytic activity than those of nanopore photoanodes. The best TiO2 nanotube photoanode was prepared at 30 V for 24 h in the ethylene glycol solution containing 0.20 mol L−1 NH4F and 0.50 mol L−1 HAc. CONCLUSION TiO2 nanotube photoelectrocatalysis technology is an effective way to decontaminate organic contaminants in water. © 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: Nano-scale TiO2 photocatalysts co-doped by rare earth ions (La3+, Ce3+) and heteropolyacids were designed and prepared by sol–gel method to probe synergistic effect on photocatalytic elimination of organic compounds, and their physicochemical properties were characterized by X-ray diffraction (XRD), specific surface area and porosity (BET and BJH), high resolution transmission electron microscopy (HRTEM), UV–vis diffuse reflectance spectroscopy (UV–vis DRS), and X-ray photoelectron spectroscopy (XPS) as well as Raman spectroscopy. The photocatalytic activity of prepared catalysts was evaluated by the degradation of methylene blue (MB) in water under UV-light irradiation. The results showed that the co-doping of the rare earth ions and heteropolyacids can significantly improve the photocatalytic activity of prepared composite photocatalysts due to the efficient inhibition of the recombination of photogenerated electron–hole pairs. The enhancement mechanism of co-doping of the rare earth ions and heteropolyacids on TiO2 is also discussed. [Copyright &y& Elsevier]

Er3+, montmorillonite (MMT) and H3PWl2O40 co-doped TiO2 photocatalyst (Er-H3PWl2O40-MMT/TiO2) was prepared by sol-gel method, and characterized by X-ray diffraction (XRD), specific surface area and porosity (BET and BJH), high resolution transmission electron microscopy (HRTEM) and Raman spectrum. The photocatalytic activity of the Er-H3PWl2O40-MMT/TiO2 was evaluated by the degradation of methylene blue (MB) under UV light irradiation. The experimental results of MB degradation demonstrated that the photocatalytic activity of Er-H3PWl2O40-MMT/TiO2 was significantly enhanced due to better separation of photogenerated electron-hole pairs, and its activity was absolutely higher than P-25 TiO2. [ABSTRACT FROM AUTHOR]

Highlight: [•] TiO2 hollow sphere multimer was obtained by etching Ti plate in NH4F solution. [•] The photocatalysts showed better degradation ability to gaseous styrene than P25. [•] Formation process includes multimer formed on Ti plate and hollowed in solution. [Copyright &y& Elsevier]

Main observation and conclusion: Ethanol is considered a better fuel than methanol in direct alcohol fuel cells because of the high energy density and low toxicity. Compared with noble metal catalysts, nickel‐based catalysts are much cheaper in price. However, present nickel‐based catalysts still surfer from some disadvantages such as low activity and high overpotential. In this paper, we show a new and high efficient nickel‐ based catalyst for ethanol oxidation. A layer of anodized nickel passivation film (Ni‐APF) was formed on the surface of nickel sheet by anodic oxidation method with carbon dots (CDs) as co‐catalyst. At the current density of 110 mA·cm−2, the potential for Ni‐APF/CDs was only 0.541 V (vs. Ag/AgCl), which was 18.8% lower than that of Ni‐APF. Low overpotential could reduce electrode thermal loss and increase output energy. Ni‐APF/CDs showed 144.4 mA∙cm−2 peak current density at peak potential 0.662 V (vs. Ag/AgCl), which was 31% higher than that of Ni‐APF (110.3 mA∙cm−2). In this system, CDs mainly function in the increase of charge‐transfer capacity and the promotion oxidation of carbonaceous intermediates. [ABSTRACT FROM AUTHOR]