Potential of biochar g-C₃N₄ nanocomposites in soil remediation of 2,4-D with mechanistic insights and future prospects

Abstract

The widespread application of herbicides, particularly 2,4-dichlorophenoxyacetic acid (2,4-D), has raised serious concerns due to its persistence in soil and water, posing significant risks to environmental and human health. This review explores the potential of biochar/graphitic carbon nitride (g-C₃N₄) nanocomposites as a promising solution for remediating 2,4-D-contaminated soils. The synergistic combination of biochar’s high surface area and g-C3N4’s photocatalytic properties enables dual-action remediation via adsorption and photodegradation. Key operational parameters, such as nanocomposite dosage, contact time, and initial pollutant concentration, substantially affect removal efficiency. While laboratory studies demonstrate high potential, field-scale implementation remains limited due to challenges including UV light dependency, energy-intensive biochar production, surface fouling, and microbial degradation. Additionally, the long-term ecological impacts of g-C3N4 in soil environments remain underexplored. Integrating these nanocomposites with sustainable agricultural practices and biocontrol methods may improve applicability. Future research should prioritize scalability, environmental safety, and cost-effectiveness to support wider adoption. Clinical trial number: not applicable.