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Fully Solar-Powered Photoelectrochemical Conversion for Simultaneous Energy Storage and Chemical Sensing

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journal contribution
posted on 11.06.2014, 00:00 authored by Yongcheng Wang, Jing Tang, Zheng Peng, Yuhang Wang, Dingsi Jia, Biao Kong, Ahmed A. Elzatahry, Dongyuan Zhao, Gengfeng Zheng
We report the development of a multifunctional, solar-powered photoelectrochemical (PEC)–pseudocapacitive–sensing material system for simultaneous solar energy conversion, electrochemical energy storage, and chemical detection. The TiO2 nanowire/NiO nanoflakes and the Si nanowire/Pt nanoparticle composites are used as photoanodes and photocathodes, respectively. A stable open-circuit voltage of ∼0.45 V and a high pseudocapacitance of up to ∼455 F g–1 are obtained, which also exhibit a repeating charging–discharging capability. The PEC–pseudocapacitive device is fully solar powered, without the need of any external power supply. Moreover, this TiO2 nanowire/NiO nanoflake composite photoanode exhibits excellent glucose sensitivity and selectivity. Under the sun light illumination, the PEC photocurrent shows a sensitive increase upon different glucose additions. Meanwhile in the dark, the open-circuit voltage of the charged pseudocapacitor also exhibits a corresponding signal over glucose analyte, thus serving as a full solar-powered energy conversion–storage–utilization system.