Plasma-modified biochar for energy and environmental sustainability

Abstract

Biochar has recently emerged as a sustainable material with broad applicability in energy storage, contaminant removal, and carbon capture. However, its performance in these domains is often limited by intrinsic surface properties, including porosity and the abundance of functional groups. Plasma treatment has emerged as a promising postsynthesis strategy to tailor biochar’s surface chemistry and morphology. This short review highlights recent advances in the use of plasma-modified biochar for electrochemical energy storage, pollutant adsorption, and CO₂ capture. In energy storage, plasma modification enhances capacitance particularly in activated biochar by increasing surface area and functional group density. For CO₂ capture, nitrogen doping via plasma processes significantly improves adsorption capacity by enhancing surface basicity and affinity toward CO₂ molecules. In contaminant remediation, plasma treatment introduces oxygen- and nitrogen-containing functional groups, increases hydrophilicity, and promotes the formation of surface defects and active sites, collectively improving adsorption of metals and organic pollutants. Despite these promising advancements, research on plasma-treated biochar remains in its early stages, particularly in the context of direct CO₂ capture, warranting further investigation. Overall, plasma modification offers a versatile, scalable route to enhance the physicochemical properties of biochar, positioning it as a multifunctional platform for environmental and energy-related applications.