Hydrothermal synthesis of Ag-ZnO nanostructures as an advanced material for photoelectrochemical applications

Ag-ZnO nanostructures with a controllable morphology and optical band structure were prepared via a hydrothermal process. The relationship among crystallite size, morphology and optical bandgap of the synthesised Ag-ZnO nanostructures in Ag molar ratio functions was elucidated. A comparative photoelectrochemical (PEC) analysis was performed using two types of photoanodes, namely, ZnO and Ag-ZnO. After Ag loading, the thickness of ZnO nanorods decreased to 13.7 nm, indicating that the growth of ZnO nanorods was disrupted by the presence of Ag. Accordingly, the optical bandgap of the sample revealed that it underwent bathochromic change. PEC testing was performed in 0.5 M Na2SO4 electrolyte under 100 mW cm(-2) xenon light irradiation. Results showed that the 0:1 Zn:Ag sample generated a photocurrent density that was tenfold higher than that of pristine ZnO photoanode. The enhancement in photocurrent density might be attributed to the low optical energy bandgap that facilitated the charge transport process. This study presented a facile method for fabricating Ag-ZnO photoanodes with an excellent photocurrent generation for robust PEC applications.