Selective CO2 Photoreduction Enabled by Water‐stable Cu‐based Metal‐organic Framework Nanoribbons

Abstract

AbstractThe goal of photocatalytic CO2 reduction system is to achieve near 100 % selectivity for the desirable product with reasonably high yield and stability. Here, two‐dimensional metal‐organic frameworks are constructed with abundant and uniform monometallic active sites, aiming to be an emerged platform for efficient and selective CO2 reduction. As an example, water‐stable Cu‐based metal–organic framework nanoribbons with coordinatively unsaturated single CuII sites are first fabricated, evidenced by X‐ray diffraction patterns and X‐ray absorption spectroscopy. In situ Fourier‐transform infrared spectra and Gibbs free energy calculations unravel the formation of the key intermediate COOH* and CO* is an exothermic and spontaneous process, whereas the competitive hydrogen evolution reaction is endothermic and non‐spontaneous, which accounts for the selective CO2 reduction. As a result, in an aqueous solution containing 1 mol L−1 KHCO3 and without any sacrifice reagent, the water‐stable Cu‐based metal–organic framework nanoribbons exhibited an average CO yield of 82 μmol g−1 h−1 with the selectivity up to 97 % during 72 h cycling test, which is comparable to other reported photocatalysts under similar conditions.