Enhanced photocatalytic H2O2 production via a facile atomic diffusion strategy near tammann temperature for single atom photocatalysts.

Abstract

Current methods for preparing single atom catalysts (SACs) often suffer from challenges such as high synthesis temperatures, complicated procedures, and expensive equipment. In this study, a facile and universal atomic diffusion strategy near Tamman temperature (AD-T_Tam) was proposed for the synthesis of semiconductor supported non-noble metal SACs, denoted as M/S, where M = Fe, Ni, Cu, Al and S = ZnO, C₃N₄, TiO₂(A), In₂O₃. Based on the empirical T_Tam (c.a. 1/2 of the melting point) phenomenon, this strategy utilized the higher atomic mobility in bulk metals near T_Tam to facilitate the migration of metal atoms to the support surface, thereby forming SACs at a relatively low temperature. A series of M/S SACs prepared using the AD-T_Tam strategy all exhibited enhanced photocatalytic H₂O₂ production activity. Notably, Cu/ZnO achieved an H₂O₂ production rate of 986.7 μmol g^-1h^-1 through the synergistic dual pathways of the water oxidation reaction and the oxygen reduction reaction, marking a 5.4-fold increase compared to pure ZnO. The introduction of Cu single atoms significantly improved the separation and migration of charge carriers in Cu/ZnO, thereby promoting the catalytic conversion of H₂O and O₂. Overall, this strategy is easily extensible at relatively low calcination temperatures and presents great potential for industrial applications.