Facile preparation of MnO2-TiO2 nanotube arrays composite electrode for electrochemical detection of hydrogen peroxide

Abstract

The MnO₂-TNTA composite electrodes were obtained through depositing MnO₂ into TiO₂ nanotube arrays (TNTA) by successive ionic layer adsorption reaction (SILAR) and subsequent hydrothermal method. The MnO₂-TNTA nanocomposites were used as electrochemical sensors for the detection of hydrogen peroxide (H₂O₂). The preparation conditions of MnO₂-TNTA electrodes and test conditions affect the electrochemical detection performance significantly. The optimal conditions are listed as follows: the number of SILAR cycles, 6 times; KMnO₄ solution temperature, 50 °C; supporting electrolyte, 0.5 M NaOH. Under these conditions, the MnO₂-TNTA electrode exhibits the best performance for detecting H₂O₂. The optimized MnO₂-TNTA electrode has a minimum detection limit of 0.6 μM (S/N = 3) and a linear range of 5 μM ∼ 13 mM, which is much superior to the previously-reported electrodes. Moreover, the optimized MnO₂-TNTA electrode possesses high selectivity, excellent stability and good reproducibility in the detection of H₂O₂. When used in the determination of H₂O₂ content in actual samples including disinfectant and milk, it also shows good accuracy, ideal recovery (96.00% ∼ 102.67%) and high precision (RSD < 4.0%).

Keywords: Composite electrodes; Electrochemical detection; Hydrogen peroxide; MnO(2); TiO(2) nanotube arrays.