“…Among these semiconductor materials, TiO 2 is endowed with the advantages of high stability, , low price, − and high photoelectric conversion efficiency, and has received extensive academic attention. Nonetheless, the substantial recombination rate of photogenerated electron–hole pairs, abbreviated charge carrier lifetime, and narrow absorption range significantly limit its wide application in PEC water splitting. − Therefore, enhancing visible light utilization and suppressing the recombination of photogenerated carriers are the common ways to enhance the photocatalytic performance of TiO 2 . Hence, nanostructure engineering, element doping, and formation of heterojunction have been tried to suppress the carrier recombination rate, improve charge transport, and enhance the photocatalytic performance of TiO 2 .…”