Biochar for pollution mitigation and renewable energy applications toward sustainability development

In the context of fossil fuels polluting the environment and depleting energy resources, the need to find sustainable solutions becomes urgent; in which, biochar stands out thanks to its potential applications in the fields of energy and environment. Biochar is produced from biomass and possesses advantageous structural properties, such as high surface area, porosity, and diverse functional groups, as well as ease of synthesis and compatibility with a wide range of low-cost, renewable feedstocks. This review outlines key biochar production methods-thermal, chemical, and biological-and evaluates recent advancements that enhance its structure and performance. These findings show that engineered biochar exhibits strong capabilities in pollutant adsorption, heavy-metal immobilization, and wastewater treatment, with surface chemistry playing a decisive role in removal efficiency. Biochar is being widely used in sustainable energy technologies, from electrode fabrication to renewable fuel production, due to its cost and environmental advantages. This review summarizes the potential of decentralized biochar production models for waste management and circular economy, identifies current research gaps, and discusses opportunities for future expansion. In doing so, the paper highlights the role of biochar as a promising solution to environmental and energy challenges.