Dual p-n Z-scheme heterostructure boosted superior photoreduction CO2 to CO, CH4 and C2H4 in In2S3/MnO2/BiOCl photocatalyst

The creation of a Z-scheme heterojunction is a sophisticated strategy to enhance photocatalytic efficiency. In our study, we synthesized an In 2 S 3 /MnO 2 /BiOCl dual Z-scheme heterostructure by growing BiOCl nanoplates on the sheets of In 2 S 3 nanoflowers, situated on the surface of MnO 2 nanowires. This synthesis involved a combination of hydrothermal and solution combustion methods. Experiments and density functional theory (DFT) calculations demonstrated that the In 2 S 3 /MnO 2 /BiOCl composite exhibited notable photo reduction performance and photocatalytic stability. This was attributed to the pivotal roles of BiOCl and MnO 2 in the composite, acting as auxiliaries to enhance the electronic structure and facilitate the adsorption/activation capacity of CO 2 and H 2 O. The yield rates of CO, CH 4 , and C 2 H 4 over In 2 S 3 /MnO 2 /BiOCl as the catalyst were 3.94, 5.5, and 3.64 times higher than those of pure In 2 S 3 , respectively. Photoelectrochemical analysis revealed that the dual Z-scheme heterostructure, with its oxygen vacancies and large surface area, enhanced CO 2 absorption and active sites on the nanoflower/nanowire intersurfaces. Consequently, the dual Z-scheme charge transfer pathway provided efficient channels for boosting electron transfer and charge separation, resulting in high C 2 H 4 , CH 4 , and CO yields of formed and exihibits an promising photoreduction rate of CO 2 to CO (51.2 µmol/g.h), CH 4 (42.4 µmol/g.h) and C 2 H 4 (63.2 µmol/g.h), respectively. DFT, in situ Diffuse reflectance infrared fourier transform spectroscopy, and temperature-programmed desorption tests were employed to verify the intermediates pathway. The study proposed a potential photocatalytic mechanism based on these findings.