Abstract
Obtaining high-value-added products like C_(2+) hydrocarbons from CO2 reduction in a photocatalytic system has always remained a great challenge. Herein we fabricated a π-π stacking hybrid photocatalyst by combining two two-dimensional (2D) materials of g-C3N4 and Cu-porphyrin metal-organic framework (MOF). This hybrid photocatalyst exhibited the excellent capability to reduce CO2 into C2H6 in a selectivity of 44% and the selectivity of total hydrocarbons (C2H6 and CH4) was as high as 71%, as one of the best performances among the reported photocatalytic systems. The node sites of 2D-MOF were identified to be critical for the generation of C2H6, and a self-reconstruction during photocatalysis was clarified: the initial paddle-wheel Cu~(II)2(COO)4 node was reconstructed to the partially reduced Cu~(1+δ)_2(COO)3. Such reconstruction strengthened the trapping of in-situ generated CO and the synergistic action of the dual-Cu-site, therefore, achieved the efficient C-C coupling to form C2H6.
NSTL