Department of Materials Science and Engineering, North Carolina State University , Raleigh, North Carolina 27695, United States.
Department of Chemistry, Duke University , Durham, North Carolina 27708, United States.
J Am Chem Soc. 2017 Nov 15;139(45):16194-16200. doi: 10.1021/jacs.7b07450. Epub 2017 Nov 2.
MoS presents a promising catalyst for the hydrogen evolution reaction (HER) in water splitting, but its worse catalytic performance in neutral and alkaline media than in acidic environment may be problematic for practical application. This is because the other half reaction of water splitting, i.e., oxygen evolution reaction, often needs to be implemented in alkaline environment. Here we demonstrate a universal strategy that may be used to significantly improve the HER catalysis of MoS in all kinds of environments from acidic to alkaline, proton intercalation. Protons may be enabled to intercalate between monolayer MoS and underlying substrates or in the interlayer space of thicker MoS by two processes: electrochemically polarizing MoS at negative potentials (vs RHE) in acidic media or immersing MoS into certain acid solutions like TFSI. The improvement in catalytic performance is due to the activity enhancement of the active sites in MoS by the intercalated protons, which might be related with the effect of the intercalated protons on electrical conductance and the adsorption energy of hydrogen atoms. The enhancement in catalytic activity by the intercalated proton is very stable even in neutral and alkaline electrolytes.
MoS 作为一种在水分解中具有前景的析氢反应 (HER) 催化剂，但其在中性和碱性介质中的催化性能不如在酸性环境中那么好，这可能会对实际应用造成问题。这是因为水分解的另一半反应，即氧气析出反应，通常需要在碱性环境中进行。在这里，我们展示了一种通用策略，可以显著提高 MoS 在从酸性到碱性的各种环境中的 HER 催化性能，即质子插层。质子可以通过两种过程插层在单层 MoS 和底层基底之间，或在较厚的 MoS 的层间空间中：在酸性介质中通过将 MoS 电化学极化至负电位（相对于 RHE）或将 MoS 浸入 TFSI 等某些酸溶液中。催化性能的提高是由于插层质子增强了 MoS 中活性位点的活性，这可能与插层质子对电导率和氢原子吸附能的影响有关。插层质子增强的催化活性在中性和碱性电解质中非常稳定。
