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Abstract: In this paper, nano-SiO2 was used as an accelerator for improving the microstructure and the corrosion resistance of phosphate coating on carbon steel. The chemical composition and microstructure of the coatings were analyzed by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The effects of nano-SiO2 on weight, roughness and corrosion resistance of the phosphate coatings were also investigated. Results show that the compositions of phosphate coating were Zn3(PO4)2·4H2O (hopeite), and Zn2Fe(PO4)2·4H2O (phosphophylite). The phosphate coatings became denser due to the addition of nano-SiO2 which reduced the size of the crystal clusters. The average weight of phosphate coatings approximately linearly increased with the nano-SiO2 content in the bath from 0 to 4g/L, and the phosphate coatings formed in bath containing 2g/L nano-SiO2 showed the highest corrosion resistance in 5wt.% sodium chloride solution at ambient temperature. Nano-SiO2 would be widely utilized as a phosphating additive to replace the traditional nitrite, due to its less pollutant and its better quality of the coating. [Copyright &y& Elsevier]

Abstract: In this paper, ultrasonic irradiation was utilized for improving the corrosion resistance of phosphate coatings on aluminum alloys. The chemical composition and morphology of the coatings were analyzed by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The effect of ultrasonic irradiation on the corrosion resistance of phosphate coatings was investigated by polarization curves and electrochemical impedance spectroscopy (EIS). Various effects of the addition of Nd2O3 in phosphating bath on the performance of the coatings were also investigated. Results show that the composition of phosphate coating were Zn3(PO4)2 ·4H2O(hopeite) and Zn crystals. The phosphate coatings became denser with fewer microscopic holes by utilizing ultrasonic irradiation treatment. The addition of Nd2O3 reduced the crystallinity of the coatings, with the additional result that the crystallites were increasingly nubby and spherical. The corrosion resistance of the coatings was also significantly improved by ultrasonic irradiation treatment; both the anodic and cathodic processes of corrosion taking place on the aluminum alloy substrate were suppressed consequently. In addition, the electrochemical impedance of the coatings was also increased by utilizing ultrasonic irradiation treatment compared with traditional treatment. [Copyright &y& Elsevier]

The CoWO 4 /CoP 2 nanoflakes grown on carbon nanotube film (CTCP/CNTF) was synthesized via hydrothermal method and can serve as an efficient bifunctional electrocatalyst for water splitting in alkaline media. • The CoWO 4 /CoP 2 nanoflakes grown on carbon nanotube film (CTCP/CNTF) was synthesized via hydrothermal method. • The CTCP/CNTF self-supported electrode exhibits excellent activity and stability for OER and HER. • The CTCP/CNTF(−) // CTCP/CNTF(+) presents particularly close activity to that of Pt/C(−) // RuO 2 (+). Tremendous efforts have been investigated in enhancing the catalytic activity of 3d-transition metal based materials (especially cobalt-based catalysts), which are regarded as promising candidates for non-noble catalysts in electrocatalytic water splitting. Herein, a facile one-step hydrothermal method is utilized to fabricate CoWO 4 /CoP 2 nanoflakes (CTCP) on carbon nanotube film (CNTF), which constructs self-supported CTCP/CNTF composite electrocatalyst for water splitting. Benefitting from the well-configured structure, CTCP/CNTF possesses more active sites for reactions along with quicker interfacial charge transfer and better electrical conductivity. Meanwhile, embedding CoP 2 in CoWO 4 yields obvious synergistic effect to improve the intrinsic catalytic activity for OER and HER. In 1.0 M KOH, the optimized CTCP/CNTF-3 electrode requires a low overpotential of 252 mV at 10 mA cm−2 (anodic current density) for OER, and 133 mV at −10 mA cm−2 (cathodic current density) for HER. When employing CTCP/CNTF as both anode and cathode, the cell voltage for overall water splitting is only 1.605 V at j cell = 10 mA cm−2, which value is extremely close to that of Pt/C/CNTF (−) // RuO 2 /CNTF (+). Remarkably, the electrolyzer (CTCP/CNTF(−) // CTCP/CNTF(+)) shows better stability for water splitting than Pt/C/CNTF (−) // RuO 2 /CNTF (+) over a duration of 32 h at j cell = 10 mA cm−2. [ABSTRACT FROM AUTHOR]

Three-dimensional ZnO/CdSe heterostructure (ZnO/CdSe HS) was fabricated with large scale and its gas-sensing application with low operating temperature was explored. Combining cost-effective chemical vapor deposition with solution growth methods, ZnO nanorods were grown on the surface of CdSe nanoribbons. Scanning electron microscopy, X-ray diffraction and transmission electron microscopy were employed to confirm the formation of ZnO/CdSe HS. The ZnO/CdSe HSs were fabricated as gas sensors in the detection of ethanol at the optimum operating temperature of 160 °C. Compared with ZnO-based gas sensors, the optimum operating temperature of the ZnO/CdSe HS-based sensor was approximately 100 °C lower, while the sensitivity was 20-fold higher in the dark and 3-fold higher under visible light illumination condition. The enhancement of sensing properties was attributed to the advanced heterostructure and visible light activated CdSe. [ABSTRACT FROM AUTHOR]

Cost-effective electrodes with high activity for hydrogen evolution reaction (HER) and durability are required to develop clean and renewable hydrogen energy. In this work, a porous Cu supported Ni-P/CeO 2 composite coating was fabricated by a facile electrodeposition technique. Owing to the contribution from the 3D porous Cu support and the incorporating agglomeration-free and uniformly distributed CeO 2 particles into the Ni-P matrix, the optimal composite coating (porous Cu supported Ni-P/CeO 2 (20 g L-1)) exhibits outstanding electrocatalytic performance with small overpotentials (η) of 118 and 320 mV at a cathodic current density of 10 and 100 mA cm2. Moreover, the composite electrode also presents excellent electrochemical stability in the alkaline solution. This work provides a feasible option to fabricate composite electrodes that may have desirable electrochemical properties for HER. [ABSTRACT FROM AUTHOR]