Rationally Designed CeO2 Nanosheets over Co9S8 Nanoparticles form S‐Scheme Heterojunction for Efficient Hydrogen Production

Abstract Enriching the active sites of catalysts and artificially regulating the directional migration of photogenerated carriers are effective means to improve the catalytic activity of photocatalysts. In this work, CeO 2 nanosheets are prepared by calcination at high temperatures, and the S‐scheme heterojunction photocatalyst CeO 2 @Co 9 S 8 is prepared by coupling the Co 9 S 8 nanoparticles prepared by hydrothermal method on CeO 2 nanosheets. The large specific surface area of CeO 2 nanosheets provides sufficient loading sites for Co 9 S 8 and Co 9 S 8 nanoparticles can effectively disperse with the help of CeO 2 nanosheet structure, which effectively inhibits the agglomeration of nanoparticles. The high photosensitivity of Co 9 S 8 increases the utilization of CeO 2 @Co 9 S 8 S‐scheme heterojunction to visible light. The construction of S‐scheme heterojunction improves the separation efficiency of photogenerated carriers, prolongs the service life of photogenerated charges, retains the photogenerated electrons and holes with strong reduction and oxidation ability in the catalyst system, and improves the performance of photocatalytic hydrogen production. The hydrogen yield of 15 wt% Co 9 S 8 supported CeO 2 @Co 9 S 8 can reach 15.7 times CeO 2 and 2.5 times Co 9 S 8 , and the composite catalyst has good stability. This work provides a new way for adjusting the surface structure and carrier behavior of photocatalysts.