Effect of Vanadium Doping on the Catalytic Activity of MoO2 Thin Films in Hydrogen Evolution Reaction.

Recently, Mo-based materials have emerged as promising candidates to replace Pt catalysts for hydrogen evolution reaction. Among these, MoO2 holds a great promise due to its metallic conductivity. Here, we investigate the effect of V doping on the hydrogen evolution reaction activity of MoO2 thin films. V doped MoO2 thin films with different dopant concentrations were prepared on conductive Si substrates by co-sputtering followed by thermal sulfurization. The electrochemical measurements revealed that V doping has an adverse effect on the hydrogen evolution reaction performance of MoO2 films, attributed to the p-type doping nature of V. This study gives insight into the effect of dopant type on the catalytic activity of hydrogen evolution reaction catalysts and provides a hint for the correct selection of dopant elements to enhance the activity of the existing catalyst materials.

Synthesis of ZnO, SnO2 nanoparticles and preparation of ZnO-SnO2 nanocomposites.

This article reports the preparation of ZnO-SnO2 nanocomposites from ZnO and SnO2 nanoparticles produced by homogenous precipitation route. Zinc acetate dihydrate (Zn(CH3COO)2 x 2H2O) and tin(II) chloride dehydrates (SnCl2. 2H2O) have been used as precursors. Distilled water was used as a solvent, monoethanolamine (MEA) is used as sol stabilizer. Precursors individually dissolved and stirred at 60 degrees C for 1 h. Certain amount of MEA were added to solution and stirred for 2 h. Then solution was cooled to room temperature and gets precipitated. The collected nanosized precipitates were mixed together and deposited on glass substrates by drain coating and post-heated at different temperatures. X-ray diffractometer was used to determine preferred crystal orientation and particle size of the thin films. Morphologies of nanopowders were examined by scanning electron microscope (SEM).