Usui, Hiroyuki Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University / Center for Research on Green Sustainable Chemistry, Tottori University Tottori University Researchers KAKEN Search Researchers
Suzuki, Shin Course of Chemistry and Biotechnology, Department of Engineering, Graduate School of Sustainability Science, Tottori University / Center for Research on Green Sustainable Chemistry, Tottori University
Domi, Yasuhiro Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University / Center for Research on Green Sustainable Chemistry, Tottori University Tottori University Researchers KAKEN Search Researchers
We prepared composite electrodes by using rutile TiO2 particles and γ-MnO2 particles, and evaluated their photoelectrochemical capacitor properties based on Na+ adsorption by light irradiation in aqueous electrolytes. By employing different synthesis method for TiO2 particles, we synthesized TiO2 particles with various particle sizes and crystallite sizes. An electrode of sol-gel-synthesized TiO2 showed higher photovoltages compared with an electrode of commercial TiO2. This probably originates from a larger contact area between electrode surface and electrolyte because of its smaller particle size than commercial TiO2's size. A further enhancement in photovoltage was attained for an electrode of a hydrothermally-synthesized TiO2 with good crystallinity. We consider that electron-hole recombination was suppressed because hydrothermal TiO2 has a lower density of lattice defect trapping the photoexcited carriers. As photoelectrochemical capacitor, a composite electrode consisting of hydrothermal TiO2 and MnO2 exhibited a 2.4 times larger discharge capacity compared with that of commercial TiO2 and MnO2. This result is attributed to an increased amount of Na+ adsorption induced by the enhanced photovoltage of TiO2.
Materials Today Energy
Copyright © 2018 Elsevier Ltd. All rights reserved. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/
This research was published by Elsevier.: USUI, Hiroyuki, et al. TiO2/MnO2 composite electrode enabling photoelectric conversion and energy storage as photoelectrochemical capacitor. Materials today energy, 2018, 9: 229-234. https://doi.org/10.1016/j.mtener.2018.05.013
Faculty of Engineering/Graduate School of Engineering