Polymer-Mediated Self-Assembly of TiO2@Cu2O Core–Shell Nanowire Array for Highly Efficient Photoelectrochemical Water Oxidation

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• 作者：Weiyong Yuan ; Jia Yuan ; Jiale Xie ; Chang Ming Li
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：March 9, 2016
• 年：2016
• 卷：8
• 期：9
• 页码：6082-6092
• 全文大小：814K
• ISSN：1944-8252

文摘

Phototoelectrochemical (PEC) water splitting represents a highly promising strategy to convert solar energy to chemical energy in the form of hydrogen, but its performance is severely limited by the water oxidation reaction. We conformally grew an ultrathin and continuous coating of Cu<sub>2sub>O on TiO<sub>2sub> nanowire array (NWA) to form a truly core–shell TiO<sub>2sub>@Cu<sub>2sub>O NWA via a new facile, economical, and scalable polymer-mediated self-assembly approach, in which the polymer serves as a stabilizer, reductant, and linker simultaneously. This heteronanostructure was subsequently directly used as a photoanode for PEC water splitting, showing a photocurrent density of 4.66 mA cm<sup>–2sup> at 1.23 V vs RHE in 0.5 M Na<sub>2sub>SO<sub>4sub> solution and a maximum photoconversion efficiency of 0.71%, both of which are the highest reported for TiO<sub>2sub>-based photoanodes measured under the same conditions (neutral conditions and without any sacrificial agent). The superior PEC performance of the TiO<sub>2sub>@Cu<sub>2sub>O NWA toward water oxidation is primarily due to much enhanced visible light collection and charge separation for high charge carrier density as well as greatly facilitated charge transfer and transport. This work not only offers a novel TiO<sub>2sub>@Cu<sub>2sub>O core–shell NWA photoanode for highly efficient PEC water oxidation and investigate its enhancement mechanism but also provides scientific insights into the mechanism of the polymer-mediated self-assembly, which can be further extended to fabricate various other core–shell nanoarchitectures for broad applications.