A Comprehensive Review of Hierarchical Porous Carbon Synthesis from Rice Husk

Hierarchical porous carbon (HPC) materials exhibit superior performance profiles in various applications due to their well-developed multiscale interconnected pore structures. The synthesis of HPC from natural biomass precursors instead of fossil fuel-based precursors has gained considerable attention in recent decades. Rice husk, a globally abundant agricultural waste, offers a sustainable and cost-effective precursor for HPC production. The structural components and inherent silica content of rice husk act as a natural self-template for forming hierarchical pore structures with superior characteristics. In this review, recent studies on preparing rice husk-based HPC are summarized, and synthesis techniques are evaluated. In addition, recent advancements in activation methods and the effect of silica templates are reviewed while comparing these with traditional activated carbon production methods. Potential future directions for research and development activities are also discussed. Rice husk is a highly promising candidate for producing high-performance HPC materials.