Improved photocatalytic carbon dioxide reduction over Bi-doped CeO₂ by strain engineering

Room-temperature photocatalytic carbon dioxide reduction reaction (CRR) is an essential method for reducing carbon footprint and achieving valuable fuels. The key challenge to accelerating the process is enhancing the catalytic rate and product selectivity. Herein, we investigate the conversion of carbon dioxide to formic acid on Bi-doped CeO2 in the presence of tensile and compressive strain by using density functional theory corrected for on-site coulombic interactions. As demonstrated, the dopant atom not only benefits the oxygen vacancy formed, but also transfers some electrons to the Ti3+ site, which is the main catalytic site for the CRR. The promising model has excellent product selectivity, offering the best catalytic performance for formic acid (Delta G(max) = 0.64 eV). Moreover, the catalytic performance is further improved by the compressive strain. The work provides novel insights into designing environment-friendly and low-cost CeO2-based photocatalysts for carbon reduction.