In situ formation of a ZnO/ZnSe nanonail array as a photoelectrode for enhanced photoelectrochemical water oxidation performance.In this study, a ZnO/ZnSe nanonail array was prepared via a two-step sequential hydrothermal synthetic route.  In this synthetic process, the ZnO nanorod array was first grown on a fluorine-doped tin oxide (FTO) substrate using a seed-mediated growth approach via the hydrothermal process.  Then, the ZnO nanonail array was obtained via in situ growth of ZnSe nano caps onto the ZnO nanorod array via a hydrothermal process in the presence of a Se source. 
THERM