Synthesis of fluorescent nitrogen-doped carbon spheres from corncob residue for the detection of Fe (III) in aqueous solutions

Water contamination has become more severe as modern industrial technology has progressed over the years. Among water contaminants are heavy metal ions such as Fe3+, which is commonly used in industries such as mining, chemical processing, and battery manufacturing. Fe3+ is the principal contaminant of concern in acid mine drainage from coal mines, causing siderosis and organ damage. The current study prepared highly photoluminescent nitrogen-doped functionalized carbon spheres (N-CSs) from corncob residue using a facile, green, and low-cost microwave synthesis. The as-prepared N-CSs exhibited an excitation-dependent fluorescence with a maximum emission and excitation at 420 and 340 nm, respectively and showed good selectivity and sensitivity towards the detection of Fe3+ with a 70 nM limit of detection.