Heteroatom‐Mediated Interactions between Ruthenium Single Atoms and an MXene Support for Efficient Hydrogen Evolution

• Published in: Advanced materials (Weinheim) Vol. 31; no. 48; pp. e1903841 - n/a
• Main Authors: Ramalingam, Vinoth, Varadhan, Purushothaman, Fu, Hui‐Chun, Kim, Hyunho, Zhang, Daliang, Chen, Shuangming, Song, Li, Ma, Ding, Wang, Yun, Alshareef, Husam N., He, Jr‐Hau
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.11.2019
• Subjects: Density functional theory; Fine structure; hydrogen evolution; Hydrogen evolution reactions; Hydrogen production; Materials science; MXene; MXenes; Nitrogen; Noble metals; Photocathodes; Photoelectric effect; Photoelectric emission; Ruthenium; Scanning transmission electron microscopy; Single atom catalysts; Titanium carbide; hydrogen evolution; photocathodes; MXene; single atom catalysts
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.201903841

A titanium carbide (Ti3C2Tx) MXene is employed as an efficient solid support to host a nitrogen (N) and sulfur (S) coordinated ruthenium single atom (RuSA) catalyst, which displays superior activity toward the hydrogen evolution reaction (HER). X‐ray absorption fine structure spectroscopy and aberration corrected scanning transmission electron microscopy reveal the atomic dispersion of Ru on the Ti3C2Tx MXene support and the successful coordination of RuSA with the N and S species on the Ti3C2Tx MXene. The resultant RuSA‐N‐S‐Ti3C2Tx catalyst exhibits a low overpotential of 76 mV to achieve the current density of 10 mA cm−2. Furthermore, it is shown that integrating the RuSA‐N‐S‐Ti3C2Tx catalyst on n+np+‐Si photocathode enables photoelectrochemical hydrogen production with exceptionally high photocurrent density of 37.6 mA cm−2 that is higher than the reported precious Pt and other noble metals catalysts coupled to Si photocathodes. Density functional theory calculations suggest that RuSA coordinated with N and S sites on the Ti3C2Tx MXene support is the origin of this enhanced HER activity. This work would extend the possibility of using the MXene family as a solid support for the rational design of various single atom catalysts. Ti3C2Tx MXene is demonstrated as a 2D solid support to host a ruthenium single atom (RuSA) catalyst for water splitting. The resultant RuSA‐N‐S‐Ti3C2Tx catalyst coupled with n+np+‐Si photocathode enables photoelectrochemical H2 production with exceptionally high photocurrent density of 37.6 mA cm−2 under AM 1.5G illumination.