Synergistic effect of iron and nitrogen co-doping on the performance of biochar for enhanced removal of pollutants...

Biochar (BC) is recognized as an excellent environmental carbon-based material for the elimination of organic contaminants and heavy metals from wastewater because of its effectiveness and low production cost. In order to further enhance the performance of BC, iron and nitrogen co-doping has emerged as an effective strategy to modify its electronic structure, thereby improving electron transfer ability, generating abundant active sites, and conferring magnetic properties. Consequently, iron and nitrogen co-doped BC (Fe/N@BC) has been successfully developed and widely applied in the elimination of organic contaminants and heavy metals from wastewater. However, there is currently no comprehensive review addressing the preparation methods, characterization, applications in the elimination of organic contaminants and heavy metals from water, and underlying removal mechanisms of Fe/N@BC. Therefore, this paper elaborates on the fabrication approaches and characterization technologies employed for Fe/N@BC. Additionally, this work explores the applications of Fe/N@BC for the adsorption and degradation of organic pollutants, as well as the sequestration of heavy metals, including its removal performances, the influences of key parameters on the removal efficiency, its removal mechanisms for organic contaminants and heavy metals from water (such as adsorption, precipitation, reduction, and activation oxidation), and the evaluation of its reusability in wastewater treatment. Finally, this review proposes future perspectives, such as the exploration of Fe/N@BC' preparation methods, expansion of its environmental applications, and assessment of its potential risks. In summary, this review aims to deepen the understanding of Fe/N@BC and promote its practical applications in wastewater treatment.