Nanoconfined Photothermal Catalysis: Mechanisms, Engineering Strategies, and Solar Fuel Synthesis

Nanoconfined photothermal catalysis enables tackling energy transition and carbon neutrality by constructing precise micro/nanoconfined spaces to boost photothermal efficiency and reaction selectivity. This review systematically examines the technology's core mechanisms, advanced material design strategies, and cutting-edge applications in solar fuel synthesis. We first elucidate how unique spatiotemporal field effects within confined microenvironments significantly improve photothermal efficiency and product selectivity, centered on efficient photothermal conversion, precise control of mass transfer-adsorption, optimized reaction pathways, and synergistic coupling of photo-thermal-mass multi-field interactions. Second, we detail key engineering strategies for high-performance catalysis: precise construction of confinement architectures, rational integration of efficient photothermal components, atomic-scale engineering of catalytic sites, and multifunctional interface optimization. The technology demonstrates transformative potential in light-driven hydrogen production, high-value CO₂ conversion, CH₄ dry/wet reforming, and directional transformation of light alkanes. However, critical challenges persist: unclear multi-physical-field coupling mechanisms; insufficient precision in sub-nanomaterial synthesis and long-term stability; thermal management-mass transfer mismatches; reaction kinetics-mass transfer trade-offs; difficulty controlling complex reaction networks; and absent scale-up pathways. This review clarifies the fundamental nature of confined catalysis to guide the development of novel multifunctional materials, break stability limits, achieve cross-scale process intensification and system integration, ultimately advancing industrial-scale, efficient, highly selective solar fuel synthesis technologies.