中国科学院大连化物所金盛烨团队报道了时间分辨光谱电化学研究析氢过程中MoS₂质子控制电子注入。相关研究成果于2025年1月22日发表于国际一流学术期刊《美国化学会杂志》。

单层MoS₂是一种有效的析氢反应（HER）电催化剂。尽管为优化活性位点做出了重大努力，但其催化性能仍低于理论预测。一个经常被忽视的关键因素是电子从导电基板注入MoS₂。基板-MoS₂界面上的电荷转移行为是非经典的，表现出液栅电子注入行为，其潜在机制仍存在争议。

为了研究这一点，研究人员采用纳秒时间分辨光谱电化学来探测在操作HER条件下单层MoS₂中的电子注入动力学。同时，瞬态电流测量提供了对基板上电子密度的见解。通过将光谱电化学分析从MoS₂获得的电子密度与瞬态电流测量得出的导电基底上的电子密度相结合，研究人员探索了电子注入动力学，并表征了基板-MoS₂界面上的电流密度势（J-E）行为。

研究结果表明，电子注入势垒和能力与电解质中的质子浓度密切相关。这种关系可能反映了MoS₂的电子浓度依赖性电导率，在注入开始之前，较高的质子浓度会导致杂散电子减少。

附：英文原文

Title: Proton-Controlled Electron Injection in MoS2 During Hydrogen Evolution Revealed by Time-Resolved Spectroelectrochemistry

Author: Tao Yang, Boning Wu, Chunmei Ding, Xianchang Yan, Wenming Tian, Shengye Jin

Issue&Volume: January 22, 2025

Abstract: Monolayer MoS2 is an effective electrocatalyst for the hydrogen evolution reaction (HER). Despite significant efforts to optimize the active sites, its catalytic performance still falls short of theoretical predictions. One key factor that has often been overlooked is the electron injection from the conductive substrate into the MoS2. The charge transfer behavior at the substrate-MoS2 interface is nonclassical, exhibiting a liquid-gated electron injection behavior, the underlying mechanism of which remain under debate. To investigate this, we employ nanosecond time-resolved spectroelectrochemistry to probe the electron injection dynamics into monolayer MoS2 under operando HER conditions. Simultaneously, transient current measurements provide insights into the electron density at the substrate. By combining the electron density obtained from the MoS2 through spectroelectrochemical analysis with the electron density at the conductive substrate derived from transient current measurements, we explore the electron injection dynamics and characterize the current density potential (J-E) behavior at the substrate-MoS2 interface. Our findings show that the electron injection barrier and capability correlate strongly with proton concentration in the electrolyte. This relationship likely reflects the electron concentration-dependent conductivity of MoS2, where higher proton concentrations lead to fewer stray electrons before injection begins.

DOI: 10.1021/jacs.4c16536

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c16536