Improving the electrochemical properties of Ti3C2Tx MXene for H2S electrochemical sensor by calcination

The existence level and metabolic mechanism of hydrogen sulfide (H2S) have been proved to have an important impact on organisms, even affecting the generation and development of many neurological diseases. Therefore, it is essential to develop sensitive and accurate H2S sensors to detect H2S concentration at trace level and provide effective research tools for studying the mechanism of action of H2S on organisms. MXene is a class of two-dimensional transition metal carbonitrides with a graphene-like structure, which indicating great application prospects as a biosensor due to its large specific surface area and good conductivity. In this work, the properties of multilayer Ti3C2Tx MXene materials are optimized concerning their physical structure and functional groups. Based on the Li + intercalation method, SL-Ti3C2Tx MXene is prepared by a mild route, and its electrochemical performance is optimized by high temperature calcination under high purity argon conditions. The change in material properties at high temperature is discussed through structural and chemical analysis, and the optimal calcination temperature is determined to be 700 °C. The constructed H2S electrochemical sensor exhibits high stability and reproducibility in applications, with a detection range of 0.1–500 μM, and the detection limit is reduced to 5.77 nM.