Direct Z-scheme CdS-CdS Nanorod Arrays Photoanode: Synthesis, Characterization and Photoelectrochemical Performance

Direct Z-scheme CdO-CdS 1-dimensional nanorod arrays were constructed through a facile and simple hydrothermal process. The structure, morphology, photoelectrochemical properties and H_2 evolution activity of this catalyst were investigated systematically. The morphology of the obtained nanorod is a regular hexagonal prism with 100-200 nm in diameter. The calcination temperature and time were optimized carefully to achieve the highest photoelectrochemical performance. The as-fabricated hybrid system achieved a photocurrent density up to 6.5 mA/cm^2 and H_2 evolution rate of 240 μmol\cdotcm^-2\cdoth^-1 at 0 V vs. Ag/AgCl, which is about 2-fold higher than that of the bare CdS nanorod arrays. The PEC performance exceeds those previously reported similar systems. A direct Z-scheme photocatalytic mechanism was proposed based on the structure and photoelectrochemical performance characterization results, which can well explain the high separation efficiency of photoinduced carriers and the excellent redox ability.