Engineering g-C3N4/Bi2WO6 Composite Photocatalyst for Enhanced Photocatalytic CO2 Reduction

As global CO2 emissions continue to rise, addressing their environmental impact is critical in combating climate change. Photocatalytic CO2 reduction, which mimics natural photosynthesis by converting CO2 into valuable fuels and chemicals using solar energy, represents a promising approach for both reducing emissions and storing energy sustainably. However, the development of efficient photocatalysts, particularly those capable of absorbing visible light, remains a challenge. Graphitic carbon nitride (g-C3N4) has gained attention for its visible light absorption and chemical stability, though its performance is hindered by rapid electron–hole recombination. Similarly, bismuth tungstate (Bi2WO6) is a visible-light-active photocatalyst with promising properties, but also suffers from limited efficiency due to charge recombination. To overcome these limitations, this study focuses on the design and synthesis of a g-C3N4/Bi2WO6 composite photocatalyst, leveraging the complementary properties of both materials. The composite benefits from enhanced charge separation through the formation of a heterojunction, reducing recombination rates and improving overall photocatalytic performance. The optimized g-C3N4/Bi2WO6 composite exhibited significant improvements in the production rates of both CH4 and CO, achieving 18.90 and 17.78 μmol/g/h, respectively, which are 2.6 times and 1.6 times higher than those of pure Bi2WO6. The study explores how optimizing the g-C3N4/Bi2WO6 interface, increasing surface area, and adjusting material ratios can further enhance the efficiency of CO2 reduction. Our findings demonstrate the potential of this composite for solar-driven CO2 conversion, offering new insights into photocatalyst design and paving the way for future advancements in CO2 mitigation technologies.