Cu doped graphitic C₃N₄ for p-nitrophenol reduction and sensing applications

A series of Cu doped graphitic carbon nitride (g-C₃N₄) catalysts with different ratios of copper were synthesized by thermal method, using urea and copper sulphate as precursors. XPS (X-ray Photoelectron Spectroscopy) studies indicated that the peak of N1s at 398.9 eV is due to Cu–N bond and a peak at 932.9 eV showed the presence of Cu–N–C bond. Catalytic hydrogenation of p-nitrophenol (Para-NP) to para-aminophenol (Para-AP) in presence of g-C₃N₄ (gCN) and copper doped g-C₃N₄ (CN-Cu) with sodium borohydride (NaBH₄) was investigated by UV–Visible spectroscopy. The as-synthesized graphitic carbon nitride with 1% copper (CN-1Cu) doped sample exhibits superior catalytic performance and higher stability compared to fine Cu powder in the second cycle. Additionally, electrochemical paracetamol sensing properties of the samples were studied using cyclic voltammetry and chronoamperometry. Consistent with the catalytic performances, CN-1Cu exhibited greater sensitivity towards the detection of paracetamol within the broad range of 38 µM to 3.64 mM and the study was carried out in the physiological pH ∼ 7.4.