Authors: Mansour, S; Akkari, R; Soto, E; Ben Chaabene, S; Mota, N; Yerga, RNM; Fierro, JLG; Zina, MS
New J. Chem.. vol: 45. page: 1144-0546.
Date: mar-07. 2021.
A series of BiVO4/TiO2 nanocomposites with high surface area have been synthesized by a sol-gel method combined with supercritical drying. BiVO4/TiO2 samples with different BiVO4 loadings were synthesized in order to study the effect of this variable on the structuration and development of BiVO4/TiO2 heterojunctions. Bare BiVO4/TiO2 composites are practically inactive for the photoproduction of hydrogen from ethanol under simulated solar light but their photoactivity notably improves after platinum (Pt) deposition. The photocatalytic activity of the Pt-BiVO4/TiO2 composites was determined by the BiVO4/TiO2 ratio that modifies the interfacial charge transfer efficiency between BiVO4 and TiO2 and also by the Pt loading that controls the dispersion and contact of the Pt particles with the composites. In particular, the composite with 0.5 wt% of Pt attained the optimal H-2 evolution rate, which is more than 100 times higher than that of the pristine BiVO4/TiO2 composite. The photoactivity of the Pt-BiVO4/TiO2 composites was explained according to the Z-scheme mechanism in which the electrons from the CB of TiO2 reduced H+ to form H-2 through the Pt particles preferentially deposited on it..