Hybrid CdS-Au nanochains with enhanced photoelectrochemistry

Metal-semiconductor nanohybrids are desirable composite materials for improving light utilization efficiency thanks to their configurable geometries and interfaces. In this paper, CdS nanochains derived from Cd(OH)₂ nanofibers are uniformly decorated by Au nanoparticles using a facile solution reduction method. The resultant one-dimensional hybrid nanostructures show enhanced photocurrents under visible light irradiation. The photoelectrochemical enhancement is dependent on the size of Au nanoparticles, which may be tuned by varying the compositions of reductants. It is found that Au nanoparticles may not only serve as electron sinks for improving charge carrier separation efficiency but also increase the visible light absorption. Optical spectroscopies and FDTD calculations indicate that larger Au nanoparticles can result in more obvious plasmonic enhancement with a greater impact of localized surface plasmon resonance on interfacial coupling.