Bi/BiOX/TiO2 NPs Nanoflowers for Photocatalytic CO2 Reduction

For a considerable time, one of the most effective and promising methods for producing value-added fuels and chemical compounds has been the photocatalytic reduction of CO₂ to CO/CH₄. However, CO₂'s high activation barrier and adverse reactions prevent it from developing further. Using ethylene glycol/water as a solvent, a multilayer BiOX(X = Cl, I) nanoparticle catalyst with plenty of oxygen vacancies was created in order to get over these restrictions. Furthermore, in situ Bi doping enhanced the photocatalyst's catalytic performance. The Bi/BiOX catalyst has a CO₂-reduced CO yield of 31.63 µmol/(g·h), which is 1.83 times higher than the initial BiOX. The results showed that the addition of Bi enhanced the quantity of reduction sites and caused a redistribution of the surface charge of BiOX, thereby improving the efficiency of photogenerated electron capture and hastening the process of photogenerated carrier separation. By combining TiO₂ and Bi/BiOX to create a heterojunction structure, the light absorption range was increased and the photogenerated carrier's separation efficiency was further improved. Bi/BiOX/TiO₂ enhanced the rate of CO₂ reduction to CO reduction products to 39.65 µmol/(g·h), which was 2.3 times greater than that of BiOX (17.29 µmol/(g·h)). The yield and selectivity of CO₂ reduction to CO are shown to be improved by in situ Bi doping in this work, offering a fresh approach to the creation of effective photocatalysts.