Hollow dodecahedron K3PW12O40/CdS core-shell S-scheme heterojunction for photocatalytic synergistic H2 evolution and benzyl alcohol oxidation

Simultaneous generation of clean energy, H-2, and organic products holds immense potential in the realm of photocatalysis. The S-scheme heterojunction stands out for these dual-function applications due to its robust redox capacity, facilitating both the water reduction reaction and organic oxidation reactions. In this study, a Keggin-type polymetallic oxide, H3PW12O40 hollow dodecahedron (KPW), was synthesized using a hydrothermal approach. Subsequently, cadmium sulfide (CdS) nanoparticles averaging 15 nm in size were integrated in situ onto the KPW shell, resulting in the creation of a core-shell KPW@CdS S-scheme heterojunction. This optimized composite showcased a hydrogen evolution rate of 18.7 mmol g(-1) h(-1), alongside a value-added product, benzaldehyde, with a yield of 17.5 mmol g(-1) h(-1) substantially surpassing the performance of standalone CdS. This S-scheme junction, featuring a pronounced internal electronic field, emerges between the KPW and CdS. It significantly enhances the segregation of photogenerated carriers while preserving formida-ble redox capability. Furthermore, the hollow structure augments light absorption and utility, and the core-shell architecture delivers dual reduction and oxidation sites. As a result, the interplay between the hollow core-shell configuration and the S-scheme mode intensifies the photocatalytic activity. This research provides an innovative approach to crafting hollow S-scheme heterojunc-tions, aiming to optimize photocatalytic redox reactions for effective solar energy utilization.(c) 2023, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.