Unveiling the Roles of Lattice Strain by Ni Exsolution on Photothermal Reduction of CO₂ Activity in BaTiO₃ Catalyst

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_0.9Ti_0.9Ni_0.1O_3-δ (BTNO) perovskite oxide, hereby enhancing the photothermal reduction of CO₂. Lattice strain and Ni-exsolution dual regulation ensure that the Ni-anchored BTNO catalyst displays superb photothermal reduction activity of CO₂. It shows a CO yield of 40.50 mmol g_cat⁻¹ h⁻¹ and a CH₄ yield of 19.62 mmol g_cat⁻¹ h⁻¹, which are 14 and 73 times higher than those of BaTiO₃. In addition, in situ DRIFTS and density functional theory (DFT) calculations reveal the CO₂ 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 CO₂ through strain engineering.