Closing the loop: Waste carbon transformation into solar fuels via CdS/Bi2WO6 heterojunction

The advancement of semiconductor photocatalysis is acknowledged for its prowess as an eco-friendly, energyefficient, and cost-effective method facilitating diverse organic transformations, including CO2 photoreduction. Despite its merits, there remains room for enhancing the selectivity and efficiency of these photocatalysts. In this study, we successfully synthesized heterojunction nanocomposites comprising CdS and Bi2WO6 semiconductors to drive the CO2-to-methanol conversion, achieving a maximum yield of 9450 mu mol/g. Notably, CO (1048 mu mol/g) and H-2 (482 mu mol/g) were also produced using water within a 16-h photocatalytic period, yielding an average production rate of similar to 590 mu mol/g-h. Triethylamine played a crucial role by providing electrons to the reaction system. The recovered photocatalyst exhibited consistent performance over five cycles of photoreduction experiments. Various spectroscopic and microscopic techniques were employed to analyze the optical, catalytic, and morphological properties of both the fresh and recovered photocatalysts. The introduced S-scheme heterojunction photocatalyst stands out for its efficient charge carrier separation, enhancing redox capacity, and holds promise as a source for novel strategies to improve the efficiency of CO2 photoreduction experiments.