Advances in interfacial engineering of MXene-based photocatalysts for solar CO2 conversion

Abstract

MXene-based photocatalysts have emerged as a versatile platform for solar-driven CO₂ reduction, offering new routes for sustainable fuel and chemical production. This review first outlines the fundamental structure, electronic/optical properties, and synthesis strategies of MXenes relevant to photocatalysis. It then critically discusses the roles of MXenes in CO₂ reduction, including co-catalyst behavior, charge-transfer mediation, and photothermal enhancement, within diverse heterostructure architectures such as 2D/2D junctions, S-scheme and Z-scheme systems, and ternary composites. Particular emphasis is placed on interfacial engineering and surface termination control to optimize charge separation and C₁/C₂ product selectivity, along with emerging AI/ML-guided approaches for rational MXene design. Sustainability aspects of MXene synthesis and deployment, including HF-free routes, scalability, energy input, and stability, are also evaluated. Finally, key research priorities are identified, encompassing operando stability, AI-guided termination and interface control, and device-level integration, to guide the development of practical MXene-based photocatalytic CO₂ reduction technologies.