A hierarchical oxygen vacancy-rich WO3 with "nanowire-array-on-nanosheet-array" structure for highly efficient oxygen evolution reaction. Issue 12 (4th March 2019)

• Record Type: Journal Article
• Authors: Diao, Jinxiang; Yuan, Wenyu; Qiu, Yu; Cheng, Laifei; Guo, Xiaohui
• Is Part Of: Journal of materials chemistry. Volume 7:Issue 12(2019)
• Page Start: 6730
• Page End: 6739
• Publication Date: 2019-03-04
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c9ta01044k
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Hierarchical vertical WO3 nanowire arrays on vertical WO3 nanosheet arrays with rich oxygen vacancies were synthesized via a simple and facile method, and the outstanding OER performance which is superior to that of most reported state-of-the-art catalysts was reported for the first time. Abstract : The search for highly efficient non-noble metal-based catalysts for the oxygen evolution reaction (OER) has received growing attention. Herein, we demonstrate a hierarchical oxygen vacancy-rich WO3 with "nanowire array on nanosheet array" (WO3 NWA-NSA) structure as a highly efficient catalyst for the OER. The vertical structure can not only highly improve the mass loading of WO3 catalysts on Ni foam, but also provide efficient paths and channels for electron and mass transfer, leading to superior catalytic activity. Besides, the oxygen vacancies in WO3 further promote the OER activity. The as-prepared WO3 NWA-NSA catalyst requires an extremely low overpotential of 0.23 V to achieve a benchmark of 10 mA cm −2, with a Tafel slope of only 33 mV dec −1, superior to most reported state-of-the-art nonprecious metal-based catalysts and noble oxide catalysts. Further theoretical modeling calculations indicate that the electronic structure of WO3 with oxygen vacancies fits extremely well with the requirements of OER catalysts. This facile strategy provides a new avenue toward the hierarchical design of electrocatalysts, and our research opens a brand-new field for the applications of WO3 .