A green approach to the fabrication of a TiO2/NiAl-LDH core–shell hybrid photocatalyst for efficient and selective solar-powered reduction of CO2 into value-added fuels

Abstract

Exploring promising photocatalysts with high efficiency and selectivity for CO₂ reduction holds paramount significance for resolving the energy crisis and various environmental problems associated with traditional fossil fuels. Here, we rationally design a core–shell hybrid photocatalyst in which anatase TiO₂ hollow spheres serve as the core component and NiAl layered double hydroxide (LDH) nanoflakes serve as the shell component. The synthesis of the TiO₂/LDH core–shell hybrid involves hydrothermal and calcination treatments without the use of environmentally toxic solvents or surfactants. Assorted experimental results demonstrate that the TiO₂/LDH core–shell hybrid exhibits a strong light-harvesting ability, large surface area, porous structure, and extraordinary CO₂ adsorption capability. In addition, the unique core–shell geometric structure of the TiO₂/LDH hybrid results in a large interfacial contact area and thus provides a broader platform for efficient charge transfer. Benefiting from these structural and compositional features, the TiO₂/LDH core–shell hybrid exhibits remarkable CO₂ reduction activity, high selectivity (against water reduction), and more importantly, good stability during consecutive test cycles. Therefore, this work offers a promising approach to the rational design and fabrication of core–shell hybrid photocatalysts with potential applications in solar energy conversion and environmental protection.