Cu, Mo-doped and pristine-BiVO4 thin films prepared by rf sputtering process for photocatalytic applications

Cu, Mo-doped and pristine BiVO4 thin films were realized by coupling rf sputtering and mechanochemical synthesis technique. These monoclinic thin films were deposited over silicon substrate under the pure argon atmosphere (Ar: 72 sccm). The sputtering targets were prepared by the respective ball-milled powders hydraulically pressed at optimal conditions. XRD analysis shows that the as-deposited thin films are amorphous and the monoclinic structure is obtained with a post-annealing process in the air at 450 A degrees C for 2 h. Compositional, morphological and optical studies were thoroughly investigated by using FE-SEM, AFM and UV-Vis absorption spectroscopies respectively and discussed as a function of photocatalytic degradation of methyl orange organic dyes in solution. The pseudo first-order degradation rate constant values were estimated as 0.028, 0.031 and 0.022 min(-1) for Cu, Mo-doped and pristine BiVO4 thin films respectively. Degradation performances are correlated as a function of their structural, surface morphological and film thickness aspects as well as the role of doping agent. Mo-doped high crystalline BiVO4 thin films with thickness 130 nm and morphology of small nano-sized islands on the surface (RMS = 5.08 nm) contributed well to the amplification of photocatalytic performance and followed by Cu doped and pristine BiVO4 thin films.