High-performance Bi2S3/Sn-doped TiO2 nanofibers for efficient photocatalytic CO2 reduction to methanol via optimized charge transfer

The rapid increase in atmospheric CO₂ levels is a major contributor to global warming. CO₂ photoreduction, which utilizes solar energy to convert CO₂ into hydrocarbon fuels, is a promising approach for reducing atmospheric CO₂. These fuels are compatible with existing energy infrastructures, making this method both practical and sustainable. However, its practical implementation requires significant advancements in terms of catalytic efficiency, charge separation, and product selectivity. In this study, we design and synthesize Bi₂S₃/Sn-doped TiO₂ nanofibers (Bi₂S₃/Sn-TiO₂ NFs) by employing electrospinning and hydrothermal methods to achieve superior photocatalytic CO₂ reduction under ultraviolet-visible (UV-Vis) irradiation. Under simulated solar light, Bi₂S₃/Sn-TiO₂ NFs exhibit threefold enhancement in CH₃OH production (529 µmol/g·h) compared to that of Sn-TiO₂ NFs (188 µmol/g·h) and pristine TiO₂ NFs (80 µmol/g·h). This significant improvement is attributed to the synergistic effect of 1D Sn-TiO₂ NFs structure, which facilitates rapid charge transport, and 0D Bi₂S₃ nanoparticles, which enhance visible light absorption and act as active sites for CO₂ adsorption and reduction. The formation of an optimized S-scheme heterojunction promoted efficient interfacial charge transfer, suppressed recombination losses, and ensured prolonged photocatalytic stability. These findings indicate that the 0D/1D composite is a highly efficient and scalable photocatalyst for CO₂-to-CH₃OH conversion, which contributes to the advancement of carbon-neutral energy technologies.