Gao Xueqing, Qi Jing, Wan Shanhong, Zhang Wei, Wang Qiang, Cao Rui
Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China.
College of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing, 211816, China.
Small. 2018 Nov;14(48):e1803361. doi: 10.1002/smll.201803361. Epub 2018 Oct 10.
Molybdenum sulfide (MoS ) is a layered material with high activity for electrocatalytic hydrogen evolution reaction (HER). In conventional MoS , the high electrical resistance between the layers hampers the bulk charge transfer and therefore greatly limits its performance in electrolysis. Herein, ultrathin MoS nanosheets with bent layers on reduced graphene oxide (RGO) are reported. In sharp contrast to the bulk MoS , the resulting MoS has mostly 1 or 2 layers, and the layer distance is significantly expanded to ≈1 nm. From computational studies, the prepared MoS with limited layer numbers and expanded layer distances has similar physical and chemical features with single-layer MoS . Importantly, the bent single layer is electrically conductive and is intrinsically more active than a normal flat single layer. In addition, the unusual features of confined sizes and distorted lattices in the prepared MoS can bring about plentiful active sites and are beneficial for mass diffusion during electrocatalysis. The hybrid material exhibits high activity for electrocatalytic HER, affording a current density of 10 mA cm at a low overpotential of 66 mV.
硫化钼（MoS ）是一种对电催化析氢反应（HER）具有高活性的层状材料。在传统的MoS 中，层间的高电阻阻碍了体电荷转移，因此极大地限制了其在电解中的性能。在此，报道了在还原氧化石墨烯（RGO）上具有弯曲层的超薄MoS纳米片。与块状MoS 形成鲜明对比的是，所得的MoS大多为1或2层，层间距显著扩大至约1nm。通过计算研究，制备的层数有限且层间距扩大的MoS与单层MoS具有相似的物理和化学特征。重要的是，弯曲的单层具有导电性，并且本质上比正常的平坦单层更具活性。此外，制备的MoS中受限尺寸和扭曲晶格的不寻常特征可以带来大量活性位点，并有利于电催化过程中的质量扩散。该混合材料对电催化HER表现出高活性，在66mV的低过电位下提供10mA cm 的电流密度。
