Photoelectrothermocatalytic reduction of CO2 to glycol via CdIn2S4-N/C hollow heterostructure mimicking plant cell

Abstract

A series of novel semiconductor composites of CdIn2S4-N/C, in which CdIn2S4 is grown on hollow nitrogen-doped carbon spheres to mimic plant cells, were designed and applied to photoelectrothermocatalytic reduction of CO2. Our results reveal that the unique hollow structure and photothermal properties of N/C contribute to excellent performance of catalyst in CO2 reduction. Specifically, the optimal catalyst of CdIn2S4-N/C-2–800 demonstrates an outstanding catalytic activity with a formation rate of 168.5 µM h−1 cm−2 for carbon-based products and an electron selectivity for C2 products of 66.9 %. DFT calculations demonstrate that pyridine N and pyrrole N can reduce the energy barrier during CO2 reduction. Two important species of *=C=O and OC-COH* were detected by operando IR spectra and suggested to be key intermediates to C2 products via a carbene (*=C=O) coupling mechanism. CdIn2S4-N/C provides thermoelectrons and active sites like in the membrane of plant to enhance the probability of C-C coupling.