We developed floatable photocatalytic hydrogel nanocomposites (^(ⅰ)Nature Nanotechnology, 2023) and nitrogen-fixing microbial biocomposites (^(ⅱ)Advanced Materials, 2023) for efficient and sustainable solar hydrogen production. A compact device integrating photocatalysis and electrocatalysis for closed-loop fuel production further enhances the overall performance of hydrogen generation (^(ⅲ)Device, 2024). Building on these advancements, we are expanding our research toward plastic waste upcycling, machine learning-aided bio-hybrid optimization, H₂O₂ production via oxygen reduction reaction, synthesis of high carbon number organic fuels, and the maximized utility of solar thermal energy. Recently, polymeric stabilization of nanoscale photocatalysts has been shown to significantly extend the operational lifetime of highly efficient dispersed single-atom photocatalysts, even under harsh reaction conditions (^(M)Nature Nanotechnology, 2025), thereby enhancing the translation potential of photocatalytic solar fuel generation systems.