Self-Supported Copper Oxide Electrocatalyst for Water Oxidation at Low Overpotential and Confirmation of Its Robustness by Cu K-edge X-ray Absorption Spectroscopy

Journal Article · Thu Jan 21 00:00:00 EST 2016 · Journal of Physical Chemistry. C

DOI:https://doi.org/10.1021/acs.jpcc.5b09818· OSTI ID:1248900

Liu, Xiang; Cui, Shengsheng; Sun, Zijun; Ren, Yang; Zhang, Xiaoyi; Du, Pingwu

Developing efficient water oxidation catalysts made of earth-abundant elements is a demanding challenge that should be met to fulfill the promise of water splitting for clean energy. Herein we report an annealing approach to synthesize binder-free, self-supported heterogeneous copper oxide (CuO) on conductive electrodes for oxygen evolution reaction (OER), producing electrodes with excellent electrocatalytic properties such as high efficiency, low overpotential, and good stability. The catalysts were grown in situ on fluorine-doped tin oxide (FTO) by electrodeposition from a simple Cu(II) salt solution, followed by annealing at a high temperature. Under optimal conditions, the CuO-based OER catalyst shows an onset potential of <0.58 V (vs Ag/AgCl) in 1.0 M KOH at pH 13.6. From the Tafel plot, the required overpotentials for current densities of 0.1 and 1.0 mA/cm2 are only 360 and 430 mV, respectively. The structure and the presence of a CuO motif in the catalyst have been identified by high-energy X-ray diffraction (HE-XRD), Cu K-edge X-ray absorption (XAS) spectra including X-ray absorption near-edge structure (XANES), and extended X-ray absorption fine structure (EXAFS). To the best of our knowledge, this represents the best catalytic activity for CuO-based OER catalysts to date.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: National Natural Science Foundation of China (NNSFC); USDOE Office of Science (SC), Basic Energy Sciences (BES); Argonne National Laboratory - Advanced Photon Source
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1248900
• Journal Information: Journal of Physical Chemistry. C, Vol. 120, Issue 2; ISSN 1932-7447
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English