Electrochemical performance of Ti3C2Tx MXene in aqueous media: towards ultrasensitive H2O2 sensing

- electrochemical characterization of MXene and oxidized MXene modified GCE.
- characterization MXene and oxidized MXene modified GCE by other optical methods.
- preparation of MXene and oxidized MXene modified GCE for detection of O2, NADH and H2O2.
- proposed mechanism for electrochemical instability of MXene at a positive potential window.
- construction of an ultrasensitive H2O2 sensor with LOD of 0.7 nM and a response time of 10 s.

An extensive characterization of pristine and oxidized Ti3C2Tx (T: O, OH, F) MXene showed that exposure of MXene to an anodic potential in the aqueous solution oxidizes the nanomaterial forming TiO2 layer or TiO2 domains with subsequent TiO2 dissolution by F− ions, making the resulting nanomaterial less electrochemically active compared to the pristine Ti3C2Tx. The Ti3C2Tx could be thus applied for electrochemical reactions in a cathodic potential window i.e. for ultrasensitive detection of H2O2 down to nM level with a response time of ∼10 s. The manuscript also shows electrochemical behavior of Ti3C2Tx modified electrode towards oxidation of NADH and towards oxygen reduction reactions.

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