Improvement of the Photoelectrochemical Stability of Cu₂O Photocathode by PhCCCu Grafting

As one of the most efficient photocathodes, Cu2O has attracted substantial attention because its theoretically high solar-to-hydrogen (STH) efficiency. However, applications in photoelectrochemical (PEC) fields are severely restricted by poor stability derived from serious photocorrosion. In this work, high-quality phenylethynyl copper (PhCCCu) successfully self-assembled on surface photocathode a novel photothermal method to improve photostability. With protection PhCCCu layer, 85% initial photocurrent density can be remained, while only 28% is left bare prepared foam (CF) substrate. The significantly improved photostability protective layer attributed strong hydrophobicity, which efficiently inhibit corrosion aqueous electrolyte solution due special crystal structure. Based obtained PhCCCu/Cu2O photocathode, two-photoelectrode cell with excellent (>5 h) also been constructed for water splitting without need an electric bias.