Nanophotonics for sustainable photocatalysis: Potential and challenges

The transition toward sustainable energy systems requires advanced catalytic technologies capable of efficiently converting solar energy into chemical fuels. In this Perspective, we critically examine the emerging role of nanophotonics in overcoming the intrinsic limitations of conventional photocatalysis, particularly the trade-off between light absorption and redox efficiency that constrains solar-to-chemical conversion. We discuss four major photonic strategies: hot carrier generation, polaritonic chemistry, enhanced photonic structures (photonic crystals), and metasurfaces/metamaterials, highlighting their potential to manipulate light–matter interactions at the nanoscale and thereby influence reaction pathways, selectivity, and efficiency. While these approaches offer compelling opportunities, including non-thermal reaction control, modification of potential energy surfaces, and improved light harvesting, their practical implementation remains hindered by fundamental and technological challenges. These include short hot-carrier lifetimes, limited reproducibility and scalability of polaritonic systems, defect sensitivity in photonic structures, and fabrication complexity and stability issues in metasurfaces. We emphasize that improvements in photocatalytic performance must be evaluated within the broader framework of overall reaction efficiency, encompassing both quantum yield and light transport. Bridging the gap between proof-of-concept studies and scalable applications will require closer integration between photonics and catalysis, along with a realistic assessment of energy costs and system-level design. Ultimately, nanophotonics provides powerful tools, but its translation into sustainable photocatalytic technologies demands a balanced and application-driven approach.