Photoelectrochemical performance and photoelectrocatalytic degradation of organic compounds using Ga:WO 3 thin films

Abstract

Abstract Polycrystalline WO3 and Ga:WO3 thin films are synthesized by spray pyrolysis technique. The photoelectrochemical (PEC) performance of PEC cell composed with WO3 and Ga:WO3 films are tested in 0.01 M HClO4. Optimized 2 at.% Ga:WO3 photoelectrode exhibits a high photocurrent density (Iph = 1.251 mA/cm2 at 1.5 V/SCE) which is 1.97 times greater than that of WO3 thin film. X-ray diffraction (XRD) and FT-Raman spectroscopy studies indicate that the films have a monoclinic crystal structure. The energy dispersive X-ray analysis of typical 2 at.% Ga:WO3 film confirms the incorporation of Ga element into WO3 film. The morphological analysis reveals that the porous microstructure of 2 at.% Ga:WO3 film. It shows remarkable enhancement in photoelectrochemical performance as compared to WO3 (petal like microstructure) and which is used for photoelectrocatalytic applications. The photoelectrocatalytic activity (with bias) is significantly higher than that of photocatalytic activity (without bias). It is interconnected with the separation of photogenerated electron-hole pairs under bias condition. Further, photoelectrocatalytic process is employed for degradation of organic compounds such as benzoic acid (BA) and salicylic acid (SA) in aqueous water using 2 at.% Ga:WO3 photocatalyst. The degradation of organic compounds in an aqueous solution of BA and SA are studied by measuring chemical oxygen demand (COD) values.