Enzyme catalysis facilitates multi-heteroatom engineering: a green path for high-performance biomass-derived...

As a renewable resource mainly composed of cellulose, the efficient and high-value utilization of wood has always been a research hotspot. Various biological enzymes play a pivotal role in the natural regeneration process of wood. Inspired by this, this study used paulownia wood, which has relatively low porosity, as the raw material for exploration. Cellulase was applied for pretreatment to construct a well-defined carbon skeleton network. After treatment with cellulase, the specific surface area of the material increased significantly from 4.1 ± 0.9 m² g^-1 to 625.4 ± 16.2 m² g^-1. The enzymatically hydrolyzed wood-derived carbon material was further modified by stepwise loading of nitrogen (N) and manganese (Mn) elements. The prepared carbon electrode material achieved a specific capacitance of 5944.0 ± 332.7 mF cm^-2 (280.4 ± 11.6 F g^-1) in a neutral three-electrode system, which is 1351 times that of the original wood. Under alkaline conditions, a higher specific capacitance performance (20.0 ± 1.1 F cm^-2, 760.3 ± 41.1 F g^-1) was achieved. The neutral supercapacitor assembled with this material exhibited an energy density of 11.6 ± 0.6 Wh kg^-1 at a 1.2 V voltage window. After 10,000 charge-discharge cycles at an electric current density of 50 mA cm^-2, it exhibited an excellent capacitance retention rate of 89.0 ± 3.4%. This study successfully applied cellulase for the green activation treatment of wood-based porous carbon. Enzyme engineering has broad prospects in the field of materials. This strategy can also be extended to other renewable resources and corresponding biological enzyme systems, providing a new entry point and research direction for the efficient and environmentally friendly preparation of supercapacitor electrode materials.