Nitrogen vacancy-modified Fe3O4 for efficient visible-light-driven CO2 photoreduction to syngas
Photocatalytic reduction of CO2 to syngas (CO and H2) is pivotal for Fischer-Tropsch synthesis and carbon neutrality, yet suffers from rapid charge carrier recombination. Here, we report a solvent-induced defect engineering strategy to fabricate nitrogen vacancy (Nv)-modified Fe3O4 (Fe3O4-Nv-12h). Under visible light (λ ≥ 420 nm), Fe3O4-Nv-12h achieves a total syngas production rate of 43.55 mmol g−1 h−1 with a near 1:1 CO/H2 ratio, representing an 805.2-fold enhancement over pristine Fe3O4 and surpassing state-of-the-art systems. Electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) confirm that Nv introduction modulates the electronic structure, acting as electron traps to suppress recombination and enhance charge transport. In situ Fourier transform infrared (FTIR) spectroscopy identifies *COOH and *CO as key intermediates for CO formation. This work establishes an effective nitrogen vacancy modification strategy for efficient photocatalytic CO2 conversion to syngas, offering new avenues for high-performance catalyst design.