Ordered intracrystalline pores in planar molybdenum oxide for enhanced alkaline hydrogen evolution

Farjana Haque; Ali Zavabeti; Bao Yue Zhang; Robi S. Datta; Yuefeng Yin; Zhifeng Yi; Yichao Wang; Nasir Mahmood; Naresh Pillai; Nitu Syed; Hareem Khan; Azmira Jannat; Ning Wang; Nikhil Medhekar; Kourosh Kalantar-zadeh; Jian Zhen Ou

doi:10.1039/C8TA08330D

Ordered intracrystalline pores in planar molybdenum oxide for enhanced alkaline hydrogen evolution†

Farjana Haque,

^a Ali Zavabeti,^a Bao Yue Zhang,^a Robi S. Datta,^a Yuefeng Yin,^bg Zhifeng Yi,^c Yichao Wang,^d Nasir Mahmood,

^a Naresh Pillai,^a Nitu Syed,^a Hareem Khan,^a Azmira Jannat,^a Ning Wang,*^e Nikhil Medhekar,

*^bg Kourosh Kalantar-zadeh

*^af and Jian Zhen Ou

*^a

Author affiliations

* Corresponding authors

^a School of Engineering, RMIT University Melbourne, Victoria, Australia
E-mail: jianzhen.ou@rmit.edu.au

^b School of Materials Science and Engineering, Monash University, Clayton, Victoria, Australia
E-mail: nikhil.medhekar@monash.edu

^c Institute for Frontier Materials, Deakin University, Geelong, Victoria, Australia

^d School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia

^e State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan, China
E-mail: wangn02@foxmail.com

^f School of Chemical Engineering, University of New South Wales, Sydney, New South Wales, Australia
E-mail: k.kalantar-zadeh@unsw.edu.au

^g School of Physics and Astronomy, Monash University, Clayton, Victoria, Australia

Abstract

Molybdenum based compounds are an emerging class of non-metallic catalytic materials for the hydrogen evolution reaction (HER) in acidic media. However, most of them lose considerable catalytic performance and exhibit poor long-term stability in alkaline media. Here, planar molybdenum oxide, with high alkaline stability and ordered intracrystalline pores, is developed as the HER candidate. The pores with diameters in the order of ∼5–7 Å are HER-active, and appear after an NH₄⁺ doping-driven phase transition from the orthorhombic to hexagonal phase. Such a unique structure facilitates the diffusion of ionic entities and water molecules to the HER sites and helps in the removal of gaseous products, therefore improving the surface active area and reaction kinetics. These intracrystalline pores also reduce the long term stress on electrodes. The corresponding HER activity is extremely stable for >40 h in an alkaline medium at an overpotential of 138 mV with a Tafel slope of 50 mV dec⁻¹. Such properties offer a superior combination compared to those of other reported molybdenum based nanostructures, hence providing a great opportunity for developing high-performance alkaline non-metal HER catalysts.

Journal of Materials Chemistry A

Ordered intracrystalline pores in planar molybdenum oxide for enhanced alkaline hydrogen evolution†

Abstract

Supplementary files

Article information

Download Citation

Permissions

Ordered intracrystalline pores in planar molybdenum oxide for enhanced alkaline hydrogen evolution

Social activity

Search articles by author

Spotlight

Advertisements