Defect-band bridge photothermally activates Type III heterojunction for CO2 reduction and typical VOCs oxidation

This work reports a novel strategy to activate type III heterojunction through introducing defect sites at the interfaces and making use of the defect band as the bridge for storage, secondary excitation, and interband transfer of the photothermal induced charges for constructing two-component Type B heterojunction photothermocatalyst. Type III heterojunction WO 3−x /GdCrO 3 is activated by defect-band state W 5/4+ at WO 3−x interface under photothermal conditions, achieving efficient charge separation, high redox potential, and full visible light absorption. The as-bridged (or Type B) heterojunction WO 3−x -R/GdCrO 3 as non-noble metal catalyst demonstrates excellent photothermocatalytic performance in toluene degradation with a reaction rate five times higher than that of WO 3−x /GdCrO 3 with less interfacial defect sites as well as in CO 2 reduction with high CO and CH 4 yielding rates of 49.6 μmol g −1 h −1 and 18.5 μmol g −1 h −1 in gas-solid reaction system without sacrifice agent, evidently better than those reported in the literature.