Built-in electric field and oxygen absorption synergistically optimized an organic/inorganic heterojunction for high-efficiency photocatalytic hydrogen peroxide production

The production of hydrogen peroxide (H 2 O 2 ) from oxygen and water is an attractive route for converting solar energy into chemical energy. In order to achieve high solar-to-H 2 O 2 conversion efficiency, floral inorganic/organic (CdS/TpBpy) composite with strong oxygen absorption and S-scheme heterojunction was synthesized by simple solvothermal-hydrothermal methods. The unique flower-like structure increased the active sites and oxygen absorption. The existence of S-scheme heterojuntion facilitated the charge transfer across the built-in electric field. Without sacrificial reagents or stabilizers, the optimal CdS/TpBpy had a higher H 2 O 2 production (3600 µmol g -1 h −1 ), which was 2.4 and 25.6 times than those of TpBpy and CdS , respectively. Meanwhile, CdS/TpBpy inhibited the H 2 O 2 decomposition, thus increasing the overall output. Furthermore, a series of experiments and calculations were carried out to verify the photocatalytic mechanism. This work demonstrates a modification method to improve the photocatalytic activity of hybrid composites, and shows potential applications in energy conversion.