Interstitial Doping in Ultrafine Nanocrystals for Efficient and Durable Water Splitting

Minming Jiang; Jiang Xu; Yujie Chen; Luqi Wang; Qi Zhou; Paul Munroe; Linlin Li; Zong-Han Xie; Shengjie Peng

doi:10.1002/anie.202424195

Interstitial Doping in Ultrafine Nanocrystals for Efficient and Durable Water Splitting

Angew Chem Int Ed Engl. 2025 Jan 13:e202424195. doi: 10.1002/anie.202424195. Online ahead of print.

Authors

Minming Jiang¹, Jiang Xu², Yujie Chen³, Luqi Wang⁴, Qi Zhou⁴, Paul Munroe⁵, Linlin Li⁴, Zong-Han Xie³, Shengjie Peng⁶

Affiliations

¹ Nanjing University of Aeronautics and Astronautics, Department of Material Science and Engineering, 29 Yudao Street, 210016, Nanjing, CHINA.
² NUAA: Nanjing University of Aeronautics and Astronautics, College of Materials Science and Technology, 29 Yudao Street, 210016, Nanjing, CHINA.
³ The University of Adelaide, School of Mechanical Engineering, AUSTRALIA.
⁴ NUAA: Nanjing University of Aeronautics and Astronautics, College of Materials Science and Technology, CHINA.
⁵ University of New South Wales, School of Materials Science and Engineering, AUSTRALIA.
⁶ Nanjing University of Aeronautics and Astronautics, College of Materials Science and Technology, No. 169 Sheng Tai West Road, Jiangning District, Nanjing, Jiangsu, China, 211106, Nanjing, CHINA.

PMID: 39806983
DOI: 10.1002/anie.202424195

Abstract

Transition metal-based catalysts with high efficiency and stability for overall water splitting (OWS) offer significant potential for reducing green hydrogen production costs. Utilizing sputtering deposition technology, we propose a deposition-diffusion strategy to fabricate heterojunction coatings composed of ultrafine FeCoNi-C-N transition metal interstitial solid solution (TMISS) nanocrystals and amorphous nitrided carbon (NC) on the pre-deposited NC micro column arrays. The diffusion of C and N atoms results in the formation of uniformly distributed TMISS nanocrystals, with an average diameter of ~1.9 nm, thus maximizing atomic utilization. The unique crystalline-amorphous heterojunction interface enhances electrocatalytic stability. Furthermore, the electronic regulation of metal sites by interstitial C and N atoms not only optimizes the adsorption-dissociation process in hydrogen evolution reaction (HER), but also accelerates the surface reconstruction of hydroxyl oxides to enhance the oxygen evolution reaction (OER) activity. As a result, the as-prepared coating achieved overpotentials of only 62 and 237 mV for the HER and OER at 10 mA cm-2 in alkaline electrolytes, and exhibited excellent OWS performance and long-term stability at high current densities. This work presents a new perspective for synthesizing TMISS nanocrystals and promotes their application in bifunctional electrocatalysts.

Keywords: Large current density; Overall water splitting; interstitial doping; solid solution; ultrafine nanocrystal.