Few-Atomic-Layers Iron for Hydrogen Evolution from Water by Photoelectrocatalysis

Baowen Zhou; Pengfei Ou; Roksana Tonny Rashid; Srinivas Vanka; Kai Sun; Lin Yao; Haiding Sun; Jun Song; Zetian Mi

doi:10.1016/j.isci.2020.101613

Few-Atomic-Layers Iron for Hydrogen Evolution from Water by Photoelectrocatalysis

iScience. 2020 Sep 28;23(10):101613. doi: 10.1016/j.isci.2020.101613. eCollection 2020 Oct 23.

Authors

Baowen Zhou^{1

2}, Pengfei Ou³, Roksana Tonny Rashid², Srinivas Vanka¹, Kai Sun⁴, Lin Yao⁵, Haiding Sun⁶, Jun Song³, Zetian Mi^{1

2}

Affiliations

¹ Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, MI 48109, USA.
² Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, QC H3A 0E9, Canada.
³ Department of Mining and Materials Engineering, McGill University, 3610 University Street, Montreal, QC H3A 0C5, Canada.
⁴ Department of Materials Science and Engineering, University of Michigan, 2300 Hayward Street, Ann Arbor, MI 48109, USA.
⁵ Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 19 Zhongguancundonglu, Beijing 100190, P. R. China.
⁶ School of Microelectronics, University of Science and Technology of China, 244 Huangshan Road, Hefei, Anhui 230026, P. R. China.

Abstract

The carbon-free production of hydrogen from water splitting holds grand promise for the critical energy and environmental challenges. Herein, few-atomic-layers iron (Fe_FAL) anchored on GaN nanowire arrays (NWs) is demonstrated as a highly active hydrogen evolution reaction catalyst, attributing to the spatial confinement and the nitrogen-terminated surface of GaN NWs. Based on density functional theory calculations, the hydrogen adsorption on Fe_FAL:GaN NWs is found to exhibit a significantly low free energy of -0.13 eV, indicative of high activity. Meanwhile, its outstanding optoelectronic properties are realized by the strong electronic coupling between atomic iron layers and GaN(10ī0) together with the nearly defect-free GaN NWs. As a result, Fe_FAL:GaN NWs/n⁺-p Si exhibits a prominent current density of ∼ -30 mA cm^-2 at an overpotential of ∼0.2 V versus reversible hydrogen electrode with a decent onset potential of +0.35 V and 98% Faradaic efficiency in 0.5 mol/L KHCO₃ aqueous solution under standard one-sun illumination.

Keywords: Atomic Electronic Structure; Catalysis; Electrochemical Energy Production; Nanoelectrochemistry; Nanomaterials.