Biomass-derived carbon materials as adsorbent materials for CO2, organic dyes, antibiotics, and heavy metals-a review

The unutilized reactants or materials and by-products from various chemical processes contribute considerably to environmental contamination, endangering both human health and aquatic ecosystems. Therefore, it is urgently imperative to implement measures to protect the environment from such contamination. Adsorption processes have emerged as a highly effective solution for this purpose owing to their operational simplicity and cost-efficiency. Among the diverse array of adsorbent materials available, biomass-derived carbon materials stand out because of their distinctive structure, excellent texture with adjustable porosity, high surface area, and low toxicity, which are attributed to their biological origin. These materials, produced from various renewable biomass sources, including agricultural residues, forest by-products, and organic waste, offer numerous benefits. This review discusses biomass-derived carbon adsorbent materials, with a focus on their applications for the removal of CO2, organic dyes, antibiotics, and toxic heavy metals. It also discusses the influence of precursor selection, activation processes, and modification techniques on adsorptive properties. The potential of these materials to address contemporary environmental challenges, coupled with their cost-effectiveness and environmental friendliness, makes them promising candidates for large-scale adsorption applications. The mechanistic pathways for adsorption and the various types of adsorption models are discussed. Future research directions are identified, highlighting the necessity of advancing synthesis techniques, understanding adsorption dynamics, and developing application-specific carbon materials.