Preparation of TiO₂/CdS/Ni(OH)₂ Composite Photoanode for Nonsacrificial Photoelectrochemical Water Splitting

Abstract

A TiO2/CdS/Ni(OH)2 composite photoanode for nonsacrificial solar water splitting is reported. In the TiO2/CdS/Ni(OH)2 composite photoanode, TiO2 not only acts as a "adhesive tape" but also forms a type II heterojunction with CdS. The double exposed crystal faces of CdS have a stronger photocatalytic reaction activity. Ni(OH)2 works as a hole transfer relay, which relieves the self-corrosion of CdS. The incident photon-to-current efficient (IPCE) value of the TiO2/CdS/Ni(OH)2 photoanode presents the maximum IPCE value, which is more than 2 times higher than the TiO2/CdS photoanode. Importantly, the TiO2/CdS/Ni(OH)2 photoanode exhibits much enhanced photocurrent, and the applied bias photon-to-current efficiency (ABPE) efficiency is 4.2 times of the TiO2/CdS photoanode. The photoelectrochemical (PEC) stability of the TiO2/CdS/Ni(OH)2 photoanode is significantly improved. This work provides new perspectives to design an efficient and stable photoanode for PEC water splitting.