Efficient carbon recycling for syngas generation through a dual-photoelectrode artificial photosynthesis system

The artificial photosynthesis system is expected to achieve efficient solar energy conversion and artificial carbon recycling. Here, a dual-photoelectrode artificial photosynthesis system is constructed by integrating Cu-p-Si NWs photocathode and FeNiO x /WO 3 /W photoanode, enabling efficient carbon dioxide reduction (CO 2 RR) and oxygen evolution reaction (OER). In the cathodic reaction, the photocathode exhibits the enhanced CO 2 RR performance under visible light irradiation, where the CO Faradaic efficiency is two times higher than the dark condition at −1.05 V vs. RHE. Syngas (CO and H 2 ) is obtained with a CO/H 2 ratio of 1:2. In the anodic reaction, the FeNiO x modified WO 3 /W photoanode displays a lower potential of 2.47 V vs. RHE at 10 mA/cm 2 compared to WO 3 /W photoanode. Moreover, the FeNiO x /WO 3 /W|Cu-p-Si NWs system exhibits a significantly reduced cell voltage at 10 mA/cm 2 . The modification with FeNiO x effectively improves the efficiency of the overall cell reaction by accelerating the sluggish OER kinetics. This work provides a feasible strategy for carbon recycling through the well-designed dual-photoelectrode artificial photosynthesis system.