Synthesis and characterization of MXene (Ti3C2Tx)/Iron oxide composite for ultrasensitive electrochemical detection of hydrogen peroxide.

Due to the widespread usage of hydrogen peroxide (H2O2) in various consumer and industrial products (Examples: fuel cells and antibacterial agents), it became important to accurately detect H2O2 concentration in environmental, medical and food samples. Herein, titanium carbide Ti3C2Tx (MXene) was synthesized by using Ti, Al and C powders at high-temperature. Then, nanocrystalline iron oxide (α-Fe2O3) was obtained from a single solid-phase method. Using Ti3C2Tx and Fe2O3 powders, Ti3C2Tx-Fe2O3 nanocomposite was prepared by ultrasonication. As-synthesized, Ti3C2Tx-Fe2O3 composite had been characterized by UV-Visible (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and Raman spectroscopy. The Fe2O3 nanoparticles (NPs) were decorated on the surface of Ti3C2Tx as observed by high resolution scanning electron microscopy (HR-SEM) and high resolution transmission electron microscopy (HR-TEM). The Ti3C2Tx nanosheets were formed with the average size of 400-500 nm. HR-SEM images of α-Fe2O3 showed that the coral-like particles with the average length ~5 μm were obtained. The electrochemical properties of the individual (Ti3C2Tx and α-Fe2O3) and composite materials (Ti3C2Tx-Fe2O3) were investigated by cyclic voltammetry (CV). Ti3C2Tx-Fe2O3 nanocomposite modified electrode had exhibited potent electro-catalytic activity for H2O2 reduction by reducing the overpotential about 320 mV and a linear response was recorded from 10 nM to 1 μM H2O2. The optimization of various parameters such as material composition ratio, amount of catalyst, effects of pH, scan rate and interference effects with other biomolecules were carried out. In addition, the kinetic parameters such as rate constant, diffusion coefficient and the active surface area of the electrodes were calculated. Moreover, the Ti3C2Tx-Fe2O3 composite modified electrode was used successfully to detect H2O2 in food and urine samples. We believe that Ti3C2Tx-Fe2O3 composite based materials could be used for the fabrication of non-enzymatic H2O2 sensors for medical diagnosis, food safety and environmental monitoring applications.