[en] Highlights: • The ZnO/CdSe based sensors worked in low temperature. • The optimum operating temperature of 160 °C is 100 °C lower than that of ZnO. • The sensitivity was 20-fold higher in dark than that of ZnO. • The sensitivity was 3-fold higher under illumination than that of ZnO. - Abstract: 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.

[en] The high-performance catalytic electrodes are always required in industrial water electrolysis for enhancing the efficiency of energy conversion. In this paper, we utilized a simple electroless deposition method to deposit Co-W-P on carbon cloth (CC), to construct a bifunctional Co-W-P/CC self-supported electrode for electrochemical water splitting in 1.0 M KOH. The Co-W-P on CC is amorphous and displays nodular structure. The molar ratio of Co²⁺/WO₄ ²⁻ in the synthesis process makes remarkable influence on the catalytic activity of Co-W-P/CC. For optimized Co-W-P/CC-3 (Co²⁺/WO₄ ²⁻ molar ratio about 6:1), an overpotential of 150 mV at −10 mA·cm⁻² is required with a Tafel slope of 137.3 mV·dec⁻¹ toward hydrogen evolution reaction (HER), and an overpotential of 350 mV at 10 mA·cm⁻² is required with a Tafel slope of 113.2 mV·dec⁻¹ toward oxygen evolution reaction (OER). Furthermore, when functioned as a bifunctional electrode for overall water splitting, the electrolyzer of Co-W-P/CC (−)//Co-W-P/CC (+) shows the cell voltage of 1.74 V at 10 mA·cm⁻², as well as superior stability with negligible increase of cell voltage (0.05 V) over 20 h. The work provides an efficient and inexpensive electrode material, which can be used to replace the noble metal-based catalysts for electrochemical water splitting. (paper)

[en] The Fe-doped CdWO₄ nanoparticles were successfully synthesized via a hydrothermal method. The morphology, crystal structure and photocatalytic activity of the products were characterized and investigated. The results show that the Fe-doping can enhance the photocatalytic efficiency of CdWO₄ for degradation of methyl orange toxic dye. The optimal Fe/Cd atomic ratio of Fe-doped CdWO₄ is identified to be 0.10. The high activity of the Fe-doped CdWO₄ catalyst would be attributed to the decrease of grain size and the doped Fe ions can trap and transfer the electron–hole pairs. (paper)

[en] MoO₂ nanospheres are successfully synthesized by a simple ethylene glycol-assisted hydrothermal route. The formation process is associated with the dissolution-recrystallization mechanism under the ethylene glycol reduction, resulting in a unique structure of that solid MoO₂ nanospheres assembled by many ultrafine primary nanoparticles. Benefiting from the hierarchical structural features, the MoO₂ nanospheres electrode displays a higher specific capacitance (204.7 and 197.4 Fg⁻¹ at 1 and 6 A g⁻¹, respectively) and exhibits a significant superior cycling stability (the specific capacitance maintains 90.6% after 1000 cycles at 1 A g⁻¹). (paper)