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

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 degrees 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 mu M (S/N = 3) and a linear range of 5 mu M similar to 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% similar to 102.67%) and high precision (RSD < 4.0%).