Plasmon-Enhanced Photoelectrochemical Water Splitting on Gold Nanoparticle Decorated ZnO/CdS Nanotube Arrays

Abstract

The design and decoration of plasmonic metal hybrid photoanodes provide an effective strategy for highly efficient photoelectrochemical (PEC) water splitting. In this work, an Au nanoparticle (NP) decorated highly ordered ZnO/CdS nanotube arrays (ZnO/CdS/Au NTAs) photoanode has been rationally designed and successfully synthesized. By virtue of the favorable band alignment and specific nanotube structure of ZnO/CdS as well as the surface plasmonic effect of Au NPs, the ZnO/CdS/Au NTAs photoanode shows significantly enhanced PEC performance as compared to the ZnO/CdS/Au and ZnO/CdS nanorod arrays (NRAs). Impressively, the optimized ZnO/CdS/Au NTAs photoanode exhibits the highest photocurrent density of 21.53 mA/cm2 at 1.2 V vs Ag/AgCl and 3.45% photoconversion efficiency (PCE) among the parallel photoanodes under visible light illumination (λ > 420 nm).