Cross-scale construction of photothermal synergistic catalytic systems: Mechanistic insights from single atoms, clusters to nanoparticles and energy conversion applications

Photothermal catalysis enhances energy conversion by coupling photoexcitation with thermal activation, yet challenges persist in spatiotemporal decoupling and multiscale transport mechanisms. This review focuses on the quantitative relationship between photothermal coupling mechanisms and energy/mass transfer across cross-scale catalytic systems (single atoms, sub-nanoclusters, and nanoparticles), systematically establishing “band structure regulation-local field engineering thermodynamic matching” cross-scale material design framework. Additionally, the mechanisms of cross-scale catalytic systems are comprehensively analyzed through multiscale characterization and theoretical modeling. In-situ synchrotron X-ray absorption spectroscopy paired with ultrafast spectroscopy exposes dynamic coordination restructuring of single atom active sites under photothermal coupling fields. Concurrently, density functional theory (DFT) integrated with finite element multi-physics simulations quantifies the relationship between cluster quantum size effects and photothermal conversion efficiency. Machine learning driven high throughput screening further advances cross-scale catalyst design principles for industrial applications such as methane reforming and water splitting. Central to this analysis are the electron-phonon coupling properties of atomic sites, quantum confinement-boosted hot carrier injection in sub-nanoclusters, and the cooperative interplay between nanoparticles plasmonic effects and macroscopic thermal gradients. This review elucidates synergistic photothermal catalysis mechanisms, establishes unified theoretical frameworks and scalable engineering strategies for efficient solar energy conversion, advancing practical implementation.