Strain engineering strengthens d-p orbital hybridization and piezo-photocatalytic molecular oxygen activation for environment remediation

The efficiency of photocatalytic O 2 activation for reactive oxygen species (ROS) generation is limited by kinetically sluggish electron transfer. Overcoming this limitation, we engineered a heterointerface (forming BaTiO 3 /Bi 12 O 17 Cl 2 , BTO/BOC) to facilitate d-p orbital hybridization by strain engineering, thereby creating a surface electron-rich region. Results demonstrate that strain engineering amplifies the d-p orbital hybridization effect, significantly enhancing O 2 adsorption strength. Furthermore, strain application enriches the electronic states near the Fermi level, enabling more electrons to migrate to the material surface to participate in O 2 activation. Consequently, the optimized BTO/BOC-3 exhibits exceptional ROS productivity, with 1.584 and 432.96 µmol g⁻¹ h⁻¹ yields for hydroxyl radical (·OH) and superoxide radical (·O 2 ⁻), respectively. This enables superior sulfamethoxazole (SMX) degradation performance, representing 2.88-fold and 11.08-fold enhancements over photocatalysis and piezo-catalysis, while toxicity simulations confirm reduced ecotoxicity of the degradation intermediates. This work pioneers a novel pathway for efficient piezo-photocatalytic ROS generation, enabling high-performance environment remediation.