Interface engineering of sandwich SiO2@α-Fe2O3@COF core-shell S-scheme heterojunctions for efficient photocatalytic oxidation of gas-phase H2S

Hydrogen sulfide (H2S) is considered to be a broad-spectrum toxicant, and it is crucial to address this problem due to its serious health and climate change impacts. Photocatalysis can be effectively applied for the reduction of H2S molecules to S and other products. We synthesized sandwich-structured composite materials with internally immobilized SiO2 nanospheres and externally wrapped COF layers co-modified with iron oxide nanoparticles. Furthermore, originally looked at the efficiency of photocatalysis in reducing hydrogen sulfide to sulfur. In this paper, a sandwich structure of core-shell composite photocatalysts based on SiO2 was prepared by a multi-step method including Stöber and double ligand-regulated solvent heat, and these sandwich core-shell structures exhibited high hydrogen sulfide reduction and stability in applications. In addition, characterization, degradation studies, active substance trapping studies, and energy band structure analysis showed that S-type heterojunctions could effectively increase photo-generated carrier separation. This research advanced knowledge of photocatalytic hydrogen sulfide reduction and offered a novel approach for catalysts in COF sandwich core-shell structures.