Nitrogen‐doped biochar as an efficient sensing material for the electrochemical detection of heavy metal ion Pb2+ and Cd2+

Abstract The sensitive detection of heavy metal ions with high toxicity and mobility is extremely important for environmental monitoring. In this study, nitrogen‐doped biochar (N‐BC) was synthesized using waste mushroom bran as a raw material, and nitrogen atoms were successfully doped onto the surface of the biochar via a facile process using an activation‐carbonation strategy. The functional groups on the surface of the biochar were enriched via doping, and the roughness of the biochar surface was significantly improved. Experimental results showed that N‐BC was an efficient sensing material for electroanalysis; therefore, it was used to construct a novel electrochemical sensing platform. The electrochemical response of the biochar‐modified working electrodes was effectively improved for the detection of heavy metals. Under optimized deposition potential, enrichment time, and pH, the N‐BC‐based sensing platform could detect Pb 2+ and Cd 2+ separately as well as simultaneously, indicating its significant potential for electrochemical sensing.