Investigating the effectiveness of g-C3N4 on Pt /g-C3N4/ polythiophene nanocomposites performance as an electrochemical sensor for Hg2+ detection

The effect of g-C3N4 on the sensing performance of a Pt/g-C3N4/ polythiophene nanocomposite (Pt/g-C3N4 /PTh NCs) was investigated in this work. The nanocomposites were synthesized via the chemical reduction of Pt (II) in the presence of L-cysteine as the reducing agent. The synthesized nanocomposite was utilized as a sensing material for the electrochemical detection of Hg2+ and was investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry and differential pulse voltammetry. The electrical resistance from EIS measurements showed a decrease of 61.87 kohm. cm(- 2) for the Pt/PTh NCs compared to the Pt/g-C3N4 /PTh NCs, due to the increase of Pt adsorption onto the active sites of g-C3N4 and PTh. A linear voltammetric response was obtained between a concentration range of 1 and 500 nM Hg2+, with a detection limit (at S/N = 3) and sensitivity of 0.009 nM and 1.0787 mu A nM(-1). cm(-2), respectively.