Abstract
Copper nanoclusters (Cu NCs) have emerged as a remarkable class of CO(2) reduction reaction catalysts that are distinguished by their unparalleled reactivity, but effectively modulating the transport pathway of charge carriers between Cu NCs by feasible chemical means is still challenging. Herein, a thermally induced covalent crosslinking strategy is proposed to modulate the fast electron transport pathway formed between clusters. A copper-sulfur-nitrogen cluster [Cu(4)(SN)(4)] (denoted Cu(4)SN) is first synthesized; subsequently, the SN ligands in Cu(4)SN are coupled covalently via a thermally induced covalent crosslinking strategy to yield CC-Cu(4)SN, which exhibits enhanced conductivity and photocarrier transport. As expected, CC-Cu(4)SN shows a high photocatalytic CO production rate of 29.98 µmol g(-1) h(-1) with ≈99.5% selectivity in CO(2) reduction with H(2)O as sacrificial agents, which is more than 10 times superior to that observed with Cu(4)SN. Systematic experiments and density functional theory calculations reveal that the covalent crosslinks between clusters accelerate the dynamic transfer of photoexcited charge carriers, increase the light utilization ability, favor CO(2) adsorption and (*)COOH generation, thereby accounting for the increased CO(2) photoreduction activity. This work presents a novel thermally induced internal covalent crosslinking strategy for synthesizing novel cluster-based covalent polymers with enhanced stability and catalytic activity.