AEROSOL METHOD FOR OBTAINING THIN FILMS OF DOPED BISMUTH VANADATE FOR WATER PHOTOLYSIS
Ключевые слова:photocurrent, molybdenum, bismuth vanadate, alloying, sacrificial electrolyte, flat zone potential
The article presents the results of research of obtaining bismuth vanadate films for processes of water photolysis by simple and reliable method of aerosol spraying of water solutions. Films of bismuth vanadate doped with molybdenum were obtained on the surface of conducting glasses. For hydrogen production systems, this is a compact, inexpensive and fast method/ At that photocurrents at a level of 1.5 mA to silver chloride reference electrode were obtained in the phosphate electrolyte with an external bias of 1.5 V, and up to 3.5 mA with addition of sulfite electrolyte. It is shown that molybdenum addition leads to an insignificant expansion and enhancement of the band in the region of 350-550 nm, and in general the system spectral characteristics are insignificant, while the system current characteristics increase significantly, 6-7 times. This is explained by increase in the mobility of electrons and holes, or by increased concentration of charge carriers caused by electron- donor elements, in particular, molybdenum. On the other hand, we associate this with the hypothesis that Mo (VI) replaces V (V) in the monoclinic main lattice of BiVO4 of scheelite type ; i.e. inclusion of Mo into BiVO4 leads to the stabilization of the tetragonal scheelite type in solid solutions in rather narrow range of compositions, which leads to a significant decrease in the current load in the system.