Optimization of In0.2Cd0.8 s-based Photocatalyst Arrays and Characterization of the Potential Photocatalysts

Abstract

In this study, a series of M-In0.2Cd0.8 s (M = La, Y, Ga, Bi, Pr, Nd and Gd) photocatalyst arrays was effectively screened with an optical fiber under UV–visible light illumination in 0.1 M Na2SO4/Na2SO3 solution by scanning electrochemical microscopy (SECM). The spot corresponding to the Ga0.3(In0.2Cd0.8)0.7 s photocatalyst displayed the highest photocatalytic activity among the photocatalyst arrays. The Ga0.3(In0.2Cd0.8)0.7 s photoelectrode possessed a hexagonal wurzite structure with a bandgap of 2.49 eV. The addition of 30% of Ga could greatly reduce the charge transfer resistance on the surface of the In0.2Cd0.8)0.7 s photocatalyst. The Ga0.3(In0.2Cd0.8)0.7 s photoelectrode exhibited a flat band position of −0.497 V vs Ag/AgCl and charge carrier density of 1.68 ± 0.15 × 1022 m−3. The maximum incident photo to current conversion efficiency (IPCE) value for the Ga0.3(In0.2Cd0.8)0.7 s photoelectrode was found to be 74% at 400 nm. The enhanced photocatalytic efficiency of the Ga0.3(In0.2Cd0.8)0.7 s photoelectrode was resulted from improvement the level of visible light energy utilization and decreased charge transfer resistance for photocatalytic reactions under optimum composition.