Recently, iChEM researchers, Prof. Changzheng Wu’s group in Prof. Yi Xie’s team made a series of important progress in the area of metallic electrocatalysts for oxygen evolution.

Environmental pollution and energy shortages caused by the continuous depletion of fossil fuels and oil are triggering considerable research interests in new kind of efficient alternative energy sources. Electrolysis hydrogen evolution is one of the efficient methods to produce clean energy, however, kinetics of the oxygen evolution reaction (OER) is usually slow, limiting efficiency of the integrated water electrolysis.

Prof. Changzheng Wu’s group designed one new kind of intrinsic metallic cobalt-based electrocatalyst. They developed metallic Co4N porous nanowire arrays directly grown on flexible substrates as highly active OER electrocatalysts for the first time. The first-principles calculations and electrical transport property measurements unravel that the Co4N is intrinsically metallic electrode material could accelerate the electron transportation, porous nanowire arrays could fully expose the active sites, while a three-dimensional configuration of electrodes could facilitate the escape of the oxygen, enhancing the stability of the electrode structure. Surface oxidation activated Co4N porous nanowire arrays/carbon cloth achieved an extremely small over potential of 257 mV at a current density of 10 mA cm-2, and a low Tafel slope of 44 mV dec-1 in an alkaline medium. This finding introduces a new concept to explore the design of high efficiency OER electrocatalysts. The result was published in Angew .Chem. Int. Ed. (Angew. Chem. Int. Ed. 2015, 10.1002/anie.201506480)

Recently, Prof. Changzheng Wu’s group made progress on the preparation of high efficient electrocatalysts based on the electrical behavior. They obtained metallic Ni3N electrode material with two-dimensional thin structure successfully through long-term exploration. Benefiting from enhanced electrical conductivity with metallic behavior and atomically disordered structure, the Ni3N nanosheets realize intrinsically improved OER activity. The result was published in JACS. (J. Am. Chem. Soc., 2015, 137 (12), pp 4119–4125). Besides, by introducing a small amount of oxygen defects and ion doping, without changing the crystal structure, improved the OER significantly by the optimization of electronics, conductivity and the active site at the same time. (Adv. Mater., 2015，27, 5989-5994)

The research was supported by the National Foundation of Science and Technology, Chinese Academy of Sciences, Collaborative Innovation Center of Chemistry for Energy Materials.

(Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemistry and Materials Science, Collaborative Innovation Center of Chemistry for Energy Materials,)

http://onlinelibrary.wiley.com/doi/10.1002/anie.201506480/full ;

http://pubs.acs.org/doi/abs/10.1021/ja5119495 ;

http://onlinelibrary.wiley.com/doi/10.1002/adma.201502024/epdf .