Nitrogen-doped biochar from algal biomass: preparation, modification, and application

Biochar derived from biomass conversion has gained widespread use in environmental applications due to its cost-effectiveness, environmental benefits, and potential for carbon neutralization. However, due to restricted pore structure and limited surface-active sites of virgin biochar, modification is usually required to improve its performance. But these modifications can increase the costs associated with pretreatment processing for biochar utilization. Algae biomass (such as algae and microalgae) is characterized by its diverse varieties, rapid propagation rate, and excellent stability, making it a highly suitable raw material for adsorbents. Nitrogen doping is one of the most commonly used methods to enhance the catalytic performance of biochar materials. The utilization of algal biomass as a foundational material, in combination with nitrogen doping, has demonstrated superior catalytic performance surpassing that of virgin biochar. In this paper, we provide a comprehensive review of the research progress on algal biomass, analyzing the pyrolysis mechanism of algal biomass and the advantages and limitations of several methods for preparing nitrogen-doped biochar. Furthermore, we explore the practical applications of nitrogen-doped biochar in catalysis, pollutant adsorption, and supercapacitors, offering valuable insights for the ongoing development of algal nitrogen-doped biochar.