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

• Published in: iScience 2020-10, Vol.23 (10), p.101613-101613, Article 101613
• Main Authors: Zhou, Baowen, Ou, Pengfei, Rashid, Roksana Tonny, Vanka, Srinivas, Sun, Kai, Yao, Lin, Sun, Haiding, Song, Jun, Mi, Zetian
• Format: Article
• Language: English
• Subjects: Atomic Electronic Structure; Catalysis; Electrochemical Energy Production; Nanoelectrochemistry; Nanomaterials
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2020.101613

The carbon-free production of hydrogen from water splitting holds grand promise for the critical energy and environmental challenges. Herein, few-atomic-layers iron (FeFAL) 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 FeFAL: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, FeFAL: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. [Display omitted] •Few-atomic-layers iron was anchored on GaN nanowires as an efficient HER catalyst•The spatial-confinement and N-rich GaN is essential for forming atomic iron layers•Low hydrogen absorption free energy is theoretically revealed over Fe3L:GaN•The device exhibits a prominent performance for PEC water splitting to H2 Catalysis; Electrochemical Energy Production; Nanoelectrochemistry; Atomic Electronic Structure; Nanomaterials