Bifunctional catalysts of Co3O4@GCN tubular nanostructured (TNS) hybrids for oxygen and hydrogen evolution reactions

• Published in: Nano research Vol. 8; no. 11; pp. 3725 - 3736
• Main Authors: Tahir, Muhammad, Mahmood, Nasir, Zhang, Xiaoxue, Mahmood, Tariq, Butt, Faheem. K., Aslam, Imran, Tanveer, M., Idrees, Faryal, Khalid, Syed, Shakir, Imran, Yan, Yiming, Zou, Jijun, Cao, Chuanbao, Hou, Yanglong
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01-11-2015; Springer Nature B.V
• Subjects: Alternative energy; Atomic/Molecular Structure and Spectra; Benchmarks; Biomedicine; Biotechnology; Carbon; Catalysis; Catalysts; Chemical engineering; Chemical synthesis; Chemistry and Materials Science; Clean energy; Cobalt oxides; Condensed Matter Physics; Conduction; Current density; Energy sources; Green energy; Hybrids; Hydrogen; Hydrogen evolution reactions; Laboratories; Low temperature; Materials Science; Metal oxides; Metals; Microscopy; Morphology; Nanostructure; Nanotechnology; Noble metals; Oxygen; Research Article; Ruthenium oxide; Splitting; Synergistic effect; Water splitting; oxygen evolution reaction; carbon nitride; bifunctional catalyst; cobalt oxide; hydrogen evolution reaction
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-015-0872-1

Catalysts for oxygen and hydrogen evolution reactions (OER/HER) are at the heart of renewable green energy sources such as water splitting. Although incredible efforts have been made to develop efficient catalysts for OER and HER, great challenges still remain in the development of bifunctional catalysts. Here, we report a novel hybrid of Co
3
O
4
embedded in tubular nanostructures of graphitic carbon nitride (GCN) and synthesized through a facile, large-scale chemical method at low temperature. Strong synergistic effects between Co
3
O
4
and GCN resulted in excellent performance as a bifunctional catalyst for OER and HER. The high surface area, unique tubular nanostructure, and composition of the hybrid made all redox sites easily available for catalysis and provided faster ionic and electronic conduction. The Co
3
O
4
@GCN tubular nanostructured (TNS) hybrid exhibited the lowest overpotential (0.12 V) and excellent current density (147 mA/cm
2
) in OER, better than benchmarks IrO
2
and RuO
2
, and with superior durability in alkaline media. Furthermore, the Co
3
O
4
@GCN TNS hybrid demonstrated excellent performance in HER, with a much lower onset and overpotential, and a stable current density. It is expected that the Co
3
O
4
@GCN TNS hybrid developed in this study will be an attractive alternative to noble metals catalysts in large scale water splitting and fuel cells.