Enhanced electrochemical performance of manganese dioxide spheres deposited on a titanium dioxide nanotube arrays substrate

The deposition of MnO sub(2) spheres on a TiO sub(2) nanotube arrays substrate are achieved via a sequential chemical bath deposition (SCBD) method for an application of anode materials in supercapacitors. The electrochemical performance of the MnO sub(2)-TiO sub(2) composite electrode is observed to show a strong dependence on the MnO sub(2) loading mass, which could be adjusted by repeating the SCBD treatment for several cycles. The optimized doses of MnO sub(2) loaded MnO sub(2)-TiO sub(2) and MnO sub(2)-Ti samples are compared in terms of their areal capacitance studies and the former is of 175 and 101 mF cm super(-2) at a scan rate of 10 and 100 mV s super(-1), respectively, which are 1.52-fold and 1.51-fold of that of the latter sample at corresponding scan rates. The enhancement in areal capacitance has been accounted to the progressive effect of the TiO sub(2) tubular substrate on the capacitive behavior of the loaded MnO sub(2) rather than the different MnO sub(2) loading mass on these two substrates. Impedance analysis reveals this enhanced electrochemical activity is owing to the tubular structure of the TiO sub(2) substrate provides an increased reaction area and facilitates the contact of electrolyte with the active MnO sub(2) material. This work justified the suitability of using the TiO sub(2) nanotube arrays for constructing high-performance supercapacitors.