TiO2/MnO2 composite electrode enabling photoelectric conversion and energy storage as photoelectrochemical capacitor
TiO2/MnO2 composite electrode enabling photoelectric conversion and energy storage as photoelectrochemical capacitor
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DOI：
10.1016/j.mtener.2018.05.013
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发表时间：
2018-09
影响因子：
9.3
通讯作者：
H. Usui;Shin Suzuki;Y. Domi;H. Sakaguchi
中科院分区：
文献类型：
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作者：
H. Usui;Shin Suzuki;Y. Domi;H. Sakaguchi
以金红石型TiO 2颗粒和γ-MnO 2颗粒为原料，制备了复合电极，并以Na+在水溶液中的光吸收为基础，研究了复合电极的光电化学电容性能。通过采用不同的合成方法，合成了不同粒径和晶粒尺寸的TiO 2颗粒。溶胶-凝胶合成的TiO 2电极显示出更高的光电压相比，商业TiO 2的电极。这可能源于电极表面与电解质之间的较大接触面积，因为其粒径小于商业TiO 2的尺寸。水热合成的TiO 2具有良好的结晶性，在光电压的进一步提高，获得的电极。我们认为，电子-空穴复合被抑制，因为水热TiO 2具有较低的晶格缺陷密度捕获的光激发载流子。作为光电化学电容器，由水热TiO 2和MnO 2组成的复合电极表现出比商业TiO 2和MnO 2大2.4倍的放电容量。这一结果是由于增加量的Na+吸附诱导的增强的光电压的TiO 2。
We prepared composite electrodes by using rutile TiO2particles and γ-MnO2particles, and evaluated their photoelectrochemical capacitor properties based on Na+adsorption by light irradiation in aqueous electrolytes. By employing different synthesis method for TiO2particles, we synthesized TiO2particles with various particle sizes and crystallite sizes. An electrode of sol–gel-synthesized TiO2showed 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 TiO2with good crystallinity. We consider that electron−hole recombination was suppressed because hydrothermal TiO2has a lower density of lattice defect trapping the photoexcited carriers. As photoelectrochemical capacitor, a composite electrode consisting of hydrothermal TiO2and MnO2exhibited a 2.4 times larger discharge capacity compared with that of commercial TiO2and MnO2. This result is attributed to an increased amount of Na+adsorption induced by the enhanced photovoltage of TiO2.