-Co(OH)₂ with interlayer anions for photocatalytic/photoelectrocatalytic water splitting

In this study, alpha-Co(OH)(2) with sulfate groups in interlayer was obtained through alkaline etching of cobalt hydroxide sulphate. The layered structure of alpha-Co(OH)(2) offers abundant adsorption sites and promotes efficient ion exchange. The introduction of sulfate ions induces changes in the electronic structure and interlayer spacing of alpha-Co(OH)(2), resulting in heightened light absorption and electrical conductivity. Experimental results and density functional theory calculations demonstrate that alpha-Co(OH)(2) has outstanding photocatalytic hydrogen evolution and photoelectrocatalytic water splitting properties. In particular, the alpha-Co(OH)(2) photoanode shows a photo-current density of 4.36 mA.cm(-2) at 1.23 V-RHE. This research not only provides an effective catalyst for photocatalytic and photoelectrocatalytic applications, but also provides insights into the underlying mechanism, which could inspire the development of materials with interlayer ions and have implications for a range of other applications.