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

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...

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Detalles Bibliográficos
Autores principales: Zhou, Baowen, Ou, Pengfei, Rashid, Roksana Tonny, Vanka, Srinivas, Sun, Kai, Yao, Lin, Sun, Haiding, Song, Jun, Mi, Zetian
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Elsevier 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7559863/
https://www.ncbi.nlm.nih.gov/pubmed/33089102
http://dx.doi.org/10.1016/j.isci.2020.101613
Descripción
Sumario: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 KHCO(3) aqueous solution under standard one-sun illumination.