WO/MnWO heterojunction for highly efficient photocatalytic reduction of CO under full spectrum light.

Solar-energy-driven CO reduction for chemical reagents production, such as CHOH, CH and CO, has tremendous potential for carbon neutrality in the energy industries. However, the low reduction efficiency limits its applicability. Herein, WO/MnWO (WMn) heterojunctions were prepared via one-step in-situ solvothermal process. Through this method, WO tightly combined with the surface of MnWO nanofibers to form nanoflower heterojunction. It was found that under full spectrum light irradiation for 4 h, the yields of photoreduction of CO to CO, CH and CHOH by 3-1 WMn heterojunction were 61.74, 71.30 and 18.98 μmol/g, respectively, which were 2.4, 1.8 and 1.1 times that of pristine WO, and ca.20 times that of pristine MnWO towards CO production. Furthermore, even in the air atmosphere, the WMn heterojunction still performed excellent photocatalytic performance. Systematic investigations demonstrated that the catalytic performance of WMn heterojunction was improved by superior light utilization and more efficient photo-generated carrier separation and migration as compared with WO and MnWO. Meanwhile, the intermediate products of the photocatalytic CO reduction process were also studied in detail by in-situ FTIR. Therefore, this study provides a new way for designing high efficiency of heterojunction for CO reduction.