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

Abstract

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 SnTiO2 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. © 2025 The Author(s). Published by Elsevier Ltd.