Unveiling the Roles of Lattice Strain by Ni Exsolution on Photothermal Reduction of CO ₂ Activity in BaTiO ₃ Catalyst

Abstract The lattice strain influences crystal orientation, facets exposed to external light, and atom rearrangement strongly to affect catalytic activity. However, how to rationally design a metal‐oxide heterojunction catalyst with featuring lattice strain is a great challenge. Herein, a facile method is adopted to induce lattice strain upon in situ exsolution of Ni nanoparticles from Ba _0.9 Ti _0.9 Ni _0.1 O _3‐δ (BTNO) perovskite oxide, hereby enhancing the photothermal reduction of CO ₂ . Lattice strain and Ni‐exsolution dual regulation ensure that the Ni‐anchored BTNO catalyst displays superb photothermal reduction activity of CO ₂ . It shows a CO yield of 40.50 mmol g _cat ⁻¹ h ⁻¹ and a CH ₄ yield of 19.62 mmol g _cat ⁻¹ h ⁻¹ , which are 14 and 73 times higher than those of BaTiO ₃ . In addition, in situ DRIFTS and density functional theory (DFT) calculations reveal the CO ₂ reduction pathways and strain modulates the interfacial band structure and enhances the transfer of photogenerated charge. Consequently, this study provides a new approach for achieving highly efficient photothermal catalytic reduction of CO ₂ through strain engineering.