Hierarchical Carbon Nanotubes with Co Nanoparticles Inside In Situ Grown on Cattail-Based Biochar via One-Step Synthesis for High-Performance Water Splitting Catalysts

Electrochemical water splitting for hydrogen production is regarded as one of the most promising key approaches for achieving sustainable energy storage in the future. However, in the field of renewable energy, the successful development of low-cost and highly efficient electrocatalysts for overall water splitting remains a major challenge to be overcome. In this study, we fabricated a nitrogen-doped composite material with a hierarchical structure (biomass carbon-carbon nanotubes-carbon nanotubes) by growing carbon nanotubes on biomass carbon-based materials through a simple one-step method. The hierarchical structure of Co/N-CNT@BC800 increases active sites, enhances reaction rate and efficiency, and ensures structural stability. The synergistic effect among the structures optimizes the electronic structure and chemical properties, further improving the catalytic performance and efficiency. Meanwhile, nitrogen doping enhances conductivity, optimizes surface chemical properties, and increases catalytic selectivity and hydrophilicity, promoting the water electrolysis reaction, reducing energy activation, and improving the performance and efficiency of the catalyst. Benefiting from the advantages of the hierarchical structure and nitrogen doping, the obtained electrocatalyst exhibits excellent electrocatalytic performance.