Efficient water oxidation through strongly coupled graphitic C3N4 coated cobalt hydroxide nanowires

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 4; no. 33; pp. 12940 - 12946
• Main Authors: Tahir, Muhammad, Mahmood, Nasir, Pan, Lun, Huang, Zhen-Feng, Lv, Zhe, Zhang, Jingwen, Butt, FaheemK, Shen, Guoqiang, Zhang, Xiangwen, Dou, Shi Xue, Zou, Ji-Jun
• Format: Journal Article
• Language: English
• Published: 01.01.2016
• Subjects: Coating; Cobalt; Current density; Electrocatalysts; Hydroxides; Nanostructure; Nanowires; Water splitting
• 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[at]g-C3N4) through an in situ hydrothermal method. With 5% g-C3N4 added in the synthesis, we obtained perfectly coated Co(OH)2 by g-C3N4 nanosheets with an overall diameter of similar to 110 nm and a coating layer of similar to 10 nm. The structural and compositional analyses confirm the strong interaction between g-C3N4 and Co(OH)2 that makes the hybrid highly effective for the OER. As a result Co(OH)2[at]g-C3N4 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 (IrO2 and RuO2) and most reported Co- and C3N4-based electrocatalysts although both Co(OH)2 and g-C3N4 separately display very fair performance. Furthermore, a combination of Co(OH)2[at]g-C3N4 and Pt/C delivers a current density of 80 mA cm-2 at 1.9 V for overall water splitting.