Efficient solar-simulated-driven valorization of non-edible oils for biodiesel production via interfacial localized photothermal catalysis

Harnessing solar energy as a power source for sustainable fuel production from biomass waste presents an effective solution to energy and environmental challenges. However, efficient utilization of low-energy near-infrared (NIR) light (representing ~50% of solar irradiance) continues a critical bottleneck especially for non-edible oils valorization. Here, we report a cellulose-derived sulfonated hydrochar (PC-SO 3 H-1) utilizing the full solar spectrum for highly efficient biodiesel production, achieving a remarkable biodiesel yield of 98.29% within only 30 min, which far exceeds the theoretical limit. Favorable NIR absorption of narrow bandgap PC-SO 3 H-1 combined with substrate adsorption capacity enhanced by -SO 3 H functionalization overcomes thermodynamic equilibrium limitations. The optimized charge transfer dynamics accelerate the interfacial localized photothermal effect, driving the esterification reaction forward while minimizing heat loss and significantly enhancing the utilization of NIR photons. Density functional theory calculations demonstrate the formation of crucial intermediate ester carbonyl groups (C=O), with PC-SO 3 H-1 effectively reducing the activation energy barrier associated with the rate-limiting process. This sustainable noble metal-free photothermal catalytic system of high-efficiency overcomes the reliance of traditional photocatalysis on high-energy photons, offering novel insights into the full spectrum solar-driven production of green and renewable biofuels.