Efficient water oxidation through strongly coupled graphitic CN coated cobalt hydroxide nanowires

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2016-08, Vol.4 (33), p.1294-12946
• Main Authors: Tahir, Muhammad, Mahmood, Nasir, Pan, Lun, Huang, Zhen-Feng, Lv, Zhe, Zhang, Jingwen, Butt, Faheem. K, Shen, Guoqiang, Zhang, Xiangwen, Dou, Shi Xue, Zou, Ji-Jun
• Format: Article
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c6ta05088c

The development of low cost and durable electrocatalysts for the oxygen evolution reaction (OER) for water splitting remains a great challenge. Here, we developed strongly coupled hybrid nanowires (NWs) of anion (Cl and CO ) doped cobalt hydroxide coated with nanosheets of graphitic carbon nitride (Co(OH) 2 @g-C 3 N 4 ) through an in situ hydrothermal method. With 5% g-C 3 N 4 added in the synthesis, we obtained perfectly coated Co(OH) 2 by g-C 3 N 4 nanosheets with an overall diameter of 110 nm and a coating layer of 10 nm. The structural and compositional analyses confirm the strong interaction between g-C 3 N 4 and Co(OH) 2 that makes the hybrid highly effective for the OER. As a result Co(OH) 2 @g-C 3 N 4 NWs exhibit an excellent over-potential of 0.32 V at 10 mA cm 2 as well as extraordinary stability, which are better than those of the state-of-the-art noble metals (IrO 2 and RuO 2 ) and most reported Co- and C 3 N 4 -based electrocatalysts although both Co(OH) 2 and g-C 3 N 4 separately display very fair performance. Furthermore, a combination of Co(OH) 2 @g-C 3 N 4 and Pt/C delivers a current density of 80 mA cm 2 at 1.9 V for overall water splitting. The activation of redox sites of Co(OH) 2 by coating g-C 3 N 4 brings outstanding over potential of 320 mV at 10 mA cm 2 and outperforms IrO 2 and RuO 2 along with best reported Co and g-C 3 N 4 based catalyst.