Photoexcited single metal atom catalysts for heterogeneous photocatalytic H2O2 production: Pragmatic guidelines for predicting charge separation

A systematic investigation of electronic configuration and excitation properties is extremely urgent for establishing a guideline to boost H2O2 production with metal single-atom photocatalysts (M-SAPCs). Herein, a series of metal-ion incorporated M-SAPCs was prepared, isolating of three transition metals (Fe, Co, Ni) and two main-group metals (In, Sn) single site by pyridinic N atoms in polymeric carbon nitride (PCN) skeleton. The models in which metal ions are isolated by non-defected g-C3N4 units (Melem_3M) are consistent with the practically prepared M-SAPC in terms of band structures and electronic configurations. Transition density and molecular orbital analysis revealed that the atomically dispersed In (III) and Sn (IV) significantly improve the charge separation with an ideal electronic configuration for the end-on adsorption of oxygen for a boosted 2e−. The experimental charge separation properties and photocatalytic activities of M-SAPC showed good accordance with the computed charge transfer profiles of Melem_3 M, manifesting the rationalities and validities of as-proposed guidelines.