Spontaneous growth of Au nanoparticles onto electrodeposited CdSe thin film for plasmonic-enhanced photoelectrochemical water splitting

This article presents a simple method for fabrication of Au-CdSe thin films onto fluorine-doped SnO2 (FTO) conducting glass substrates. The method starts with electrodeposition of CdSe thin films onto FTO substrates and followed by spontaneous growth of Au nanoparticles onto the CdSe surface in solutions containing AuCl4- ions. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) spectroscopy were used to investigate the Au-CdSe thin films. This work demonstrates that introducing plasmonic Au nanoparticles into photochemical reaction can substantially enhance the photo response to the solar splitting of water. The Au-CdSe/FTO photoelectrodes show an up to 7.5-fold enhancements of photocurrent density for photoelectrochemical water splitting, as compare to that of the bare CdSe/FTO electrode. The mechanisms of spontaneous growth of Au nanoparticles and plasmonic enhancement of the photocurrent are discussed.