Magnetic field enhanced photoelectrochemical response of a nanostructured titanium dioxide anode

Abstract

The concept of permanent-magnet photoelectrochemical fuel cell is proposed. The fuel cell contains a TiO2 nanotube anode and a platinum cathode. Water was used as the fuel. The anode has a self-organized high aspect ratio TiO2 nanotube layer made through electrochemical oxidation of Ti. Photocatalysis and permanent magnetic field excitation experiments were performed. The photoelectrochemical responses of the anode to visible (Vis) and ultraviolet (UV) light were studied to examine the magnetic field effect. The open circuit voltages were 0.0564, 0.1625, 0.1898 and 0.376V, under the excitation of Vis, UV, magnet and magnet+UV, respectively. Current density was measured under different linear potential scanning conditions. It reached a value of 5.23mA/m2 just under the excitation of the permanent magnet at a bias voltage of 2V. Combining the magnetic action and the photovoltaic effect, the titanium dioxide photosensitive anode showed a maximum photocurrent density of 296.05mA/m2 at 2V bias. It is concluded that the absolute value of open circuit voltage (OCV) of the fuel cell due to the exposure to the magnet field is much higher than that due to either UV or Vis light illumination. However, UV light excitation results in higher current density in the measurement.