Sr-tuned BaTiO3/NiFe-LDH heterostructured photocatalysts for solar-driven CO2-to-Fuel conversion

Solar-driven CO 2 conversion requires photocatalysts that combine strong redox power with efficient interfacial charge transfer. Here, Sr-tuned BaTiO 3 was coupled with NiFe-layered double hydroxide to construct a 10BST/LDH heterostructure for selective CO 2 -to-fuel conversion. Among Ba 1-x Sr x TiO 3 compositions, BST-0.15 showed the optimum structural and photocatalytic response, while 10 wt% loading on NiFe-LDH delivered the best performance. Structural, microscopic, elemental, and surface analyses confirmed the deposition of BST-0.15 nanoparticles on hierarchical NiFe-LDH nanosheets. Under irradiation, 10BST/LDH produced CO and CH 3 OH at 262.17 and 57.08 μmol g −1 h −1 , respectively, with minor H 2 and CH 4 evolution of 27.01 and 2.01 μmol g −1 h −1 . CO accounted for 81.61% of the carbon-containing products. Control experiments and 13 CO 2 tracing verified the photocatalytic origin of CO. Enhanced photocurrent, reduced impedance, irradiation-dependent ESR signals, and work-function/band-position analyses collectively indicated favourable interfacial charge redistribution, improved carrier separation, and enhanced surface redox activity. The catalyst also maintained activity during repeated irradiation and recycling. This study establishes a practical strategy for integrating compositionally tuned titanate perovskites with layered hydroxides to achieve efficient, selective, and visible-light-responsive CO 2 photoreduction. These findings advance rational heterointerface engineering toward efficient solar-fuel generation and sustainable utilization of carbon dioxide as feedstock.