Electrochemical performance and efficiency of novel copper hexacyanoferrate/graphitic carbon nitride composites for the removal of 137Cs

• The novel CuHCF/g-C 3 N 4 composite for the electrochemical adsorption of radioactive 137 Cs. • Offering excellent electrochemical performance and high removal efficiency. • Successfully applied to adsorb the radioactive 137 Cs from actual wastewater. • It is promising for the sustainable removal of radioactive contaminants in environmental settings. This study investigates the use of a novel composite material, synthesized from melamine, urea, and thiourea derived graphitic carbon nitride (g-C 3 N 4 ) and copper hexacyanoferrate (CuHCF) by ultrasonication method, for the electrochemical adsorption of 137 Cs in wastewater. The adsorption and desorption of Cs + ions in the CuHCF/g-C 3 N 4 composite can be investigated using cyclic voltammetry by alternating the applied potentials between the anode and cathode. Different g-C 3 N 4 precursors alter the structural and electrochemical properties of the composites, affecting surface area, porosity, electron transfer, and performance in 137 Cs adsorption. The novel composite materials demonstrated a significant removal efficiency that calculated to be 46.5 % for pure CuHCF, 50.6 % for CuHCF/g-C 3 N 4 -M, 59.8 % for CuHCF/g-C 3 N 4 -U, and 52.5 % for CuHCF/g-C 3 N 4 -T, utilizing an electrochemical method over 250 cycles. The proposed system was successfully employed to adsorb 137 Cs from actual wastewater. This method underscores the potential of the CuHCF/g-C 3 N 4 composite as a promising candidate for the sustainable and effective removal of radioactive 137 Cs from contaminated water sources.