Single-Atom Photocatalysis

Single-atom photocatalysis uses catalysts in which the active species are isolated metal atoms dispersed on a support (e.g. oxide, carbon, nitride), rather than nanoparticles or bulk surfaces. The resulting geometry and electronic structure can give high activity and selectivity for light-driven reactions such as water splitting, CO₂ reduction, or organic transformations. Single-atom sites maximise atom efficiency and can reduce overuse of precious metals; they also offer a well-defined environment for mechanistic study and tuning. Synthesis and characterisation of stable single-atom catalysts under reaction conditions remain active research areas.

The technology addresses the need for more efficient and selective photocatalysis in sustainable chemistry and manufacturing. By operating at the atomic scale, single-atom photocatalysts can enable cleaner reactions with lower energy input and fewer undesired by-products. Potential applications include solar fuel production, fine chemicals, and pollutant degradation. The approach sits at the intersection of catalysis, materials science, and photochemistry.

Challenges include maintaining single-atom dispersion under reaction conditions (sintering and agglomeration can occur), scaling synthesis, and matching catalyst design to specific reactions and light sources. As understanding of structure–activity relationships and stabilisation strategies improves, single-atom photocatalysis could contribute to more sustainable chemical and energy processes.