High efficiency reduction of CO2 to CO and CH4 via photothermal synergistic catalysis of lead-free perovskite Cs3Sb2I9

Solar-energy-driven CO 2 and H 2 O conversion into value-added chemical fuel holds great potential in solving the greenhouse effect problem and the energy crisis. Herein, the novel lead-free perovskite Cs 3 Sb 2 I 9 photocatalyst was developed to realize high efficiency reduction of CO 2 to CO and CH 4 by photothermal synergistic catalysis. The production rate of the novel catalytic system is 95.7 μmol g −1  h -1 without any sacrificial agents or cocatalysts, which are 87-fold and 5.2-fold higher than that of pure photocatalysis and pure thermal catalysis respectively, and an order of magnitude higher compared to previous literatures. Through the obtained evidence of the formate active intermediates, defects active sites produced in reaction process and photogenerated charge enhanced activity driven by built-in electric field, it is revealed that the defects active sites produced by the thermal excitation of Cs 3 Sb 2 I 9 photocatalyst can adsorb and activate CO 2 , while the plentiful electrons excited by light can provide the CO 2 reduction capacity, the synergistic effect of them enhance the activity of CO 2 reduction reaction. This work firstly reports the novel Sb-based perovskite material was developed as photocatalyst for artificial synthetic CO 2 and H 2 O into solar energy fuels and provides new insights on photothermal synergistic catalysis.