Morphology Modulation Of CdS And The Photoelectrochemical Catalytic Performance Of CdS/MoS₂Composites

The photoelectrochemical performances of semiconductors were largely influenced by their micro-morphologies. Here in this work, nanostructure modulation of CdS and morphology design of CdS/MoS2composites were achieved, and the influence of micro-morphology on the photoelectrochemcial performances of ITO loaded CdS/MoS2composites for hydrogen evolution reaction was detailedly investigated.Briefly, electrochemical deposition and solvothermal methods were applied to prepare CdS nanostructures which had different morphologies including sheet-like, rod-like, and urchin-like types.CdS was primarily deposited on ITO substrates. ITO loaded CdS/MoS2composites were further prepared from galvanostatic deposition of the as-prepared ITO/CdS. All of these composites performed better photoelectrochemial properties when utilized as the electrode materials for hydrogen evolution reaction. This is ascribed to the formation of p-n conjugation which can efficiently prevent the recombination of electron and hole and enlarge the response range for visible light. It was found that sheet-like CdS showed the most favorable enhancing effect for the photoelectrochemical catalytic properties of ITO loaded CdS/MoS2composite. Its short current density can reach to6times larger (8.5mA cm-2) than that of pure CdS when exposed to Xenon lamp. Moreover, the formation of sheet-like CdS-MoS2p-n conjugation in CdS/MoS2composite can additionally advance its electrochemical activity for hydrogen evolution reaction. The polarization current density of ITO loaded sheet-like CdS/MoS2exhibits33mA cm-2at-1.5V (vs. Ag/AgCl) in the cathode polarization curve, which is much larger than that of pure CdS (1.0mA cm-2) and MoS2(12.5mA cm-2). It is due to the special sheet-like morphology which can provide more reactive sites and large contact area in solution.