Highly Sensitive Titanium-Based MXene-Reduced Graphene Oxide Composite for Efficient Electrochemical Heavy Metal Detection of Cadmium and Copper Ions in Water

A simple and efficient synthesis route was introduced to develop an electrochemically active and promising binary composite that was made up of titanium based MXene (Ti3C2Tx) and rGO to simultaneously detect ions namely Cd2+ and Cu2+ in water. XRD, FTIR, Raman, XPS, FESEM, elemental mapping and EDX analysis affirmed successful formation of Ti3C2Tx-rGO composite. The produced Ti3C2Tx-rGO electrode exhibited an homogeneous rGO sheet coved Ti3C2Tx MXene plates with the all the detailed Ti2p, C1s and O1s XPS peaks. The high performance Ti3C2Tx-rGO composite was successfully tested Cd2+ and Cu2+ ions via differential pulse voltammetry (DPV), altering the pH, concentration and the real water sample quality. The electrochemical performances revealed that the proposed Ti3C2Tx-rGO composite depicted very low detection and quantification limits (LOD and LOQ) respectively, both for Cd2+ (LOD = 0.31 nM, LOQ = 1.02 nM) and Cu2+ (LOD = 0.18 nM, LOQ = 0.62 nM) ions, where the result is highly comparable with the reported literature. The Ti3C2Tx-rGO is proven highly sensitive towards Cd2+ (0.345 μMμA−1) and Cu2+ (0.575 μMμA−1) with great repeatability and reproducibility properties. Ti3C2Tx-rGO electrode was also exhibited excellent stability over four weeks with the retention of 97.86% and 98.01% for Cd2+ and Cu2+, respectively. This simple approach on modifying Ti3C2Tx utilizing rGO can potentially be advantageous in the development of highly sensitive electrochemical sensors for simultaneous detection of heavy metal ions.