Ultrathin BiOCl Single-Crystalline Nanosheets with Large Reactive Facets Area and High Electron Mobility Efficiency: A Superior Candidate for High-Performance Dye Self-Photosensitization Photocatalytic Fuel Cell.

Strong dye adsorption and fast electron transfer are of crucial importance to achieve high conversion efficiency of dye self-photosensitization photocatalytic fuel cells (DSPFCs). In this study, we have experimentally achieved the enhanced cell performance in ultrathin BiOCl{010} (BOC(010)-U) nanosheets and provide an idea to investigate the relationship between the physical structure and the chemical performance of semiconductor materials. Experimental phenomenon showed that the exposed areas of highly active {010} facets were remarkably enhanced with the decrease of the BiOCl thickness. The large area of {010} facets with abundant active sites and open channel characteristic were exposed to facilitate photosensitization process, and the atomically thin structure was designed to speed up electron transfer. By employing 40 mL of 5 mg/L rhodamine B as fuel, it was found that the BOC(010)-U photoanode exhibited superior photovoltaic performance and photocatalytic degradation activity than other materials in the DSPFC system, whose Jsc and Voc were measured to be 0.00865 mA/cm2 and 0.731 V, respectively. Besides, about 72% color removal efficiency and 10.77% Coulombic efficiency were obtained under visible light irradiation for 240 min. The experimental results and multiple characterizations demonstrated that the strong dye adsorption ability and efficient charge migration were responsible for the sustaining generation of photocurrent and enhancement of pollutants degradation activity.