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Synthetic mimics of chlorophyll, which is designed by replacing the Mg center of porphyrin unit with other metal atoms (Au, Cu, Co) on metal-organic frameworks, may maximize atom utilization and optimize catalytic activity. Simultaneously, porphyrin ligand can be easily interfered by visible light, which offers an opportunity to develop photo-coupled electrocatalyst for CO₂ reduction. The single-Au-atom catalyst exhibits an ultrahigh turnover frequency of 37069 h^-1 at -1.1 V and CO faradaic efficiency of 94.2% at -0.9 V. Interestingly, with visible light interfered (67% solar intensity), the electrocatalyst reaches an approximate turnover frequency value and faradaic efficiency with reduced potential of ~130 mV. The similar trend is also observed on single-Cu-atom electrocatalyst under visible light, displaying a positive shift of 100 mV with a highest HCOOH faradaic efficiency of 77.3% at -0.7 V versus RHE. Interestingly, the light-induced positive shifts of 20, 100 and 130 mV for single-Co-atom, single-Cu-atom and single-Au-atom electrocatalysts are in consistent with their energy gaps of 0, 1.5 and 1.7 eV, respectively, suggesting the porphyrin not only serves as ligand, but also photoswitch to regulate electron transfer pathway to metal atom.