超低密度、整体式 WS2、MoS2 和 MoS2/石墨烯气凝胶。

Ultralow Density, Monolithic WS2, MoS2, and MoS2/Graphene Aerogels.

机构信息

Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States.

出版信息

ACS Nano. 2015 May 26;9(5):4698-705. doi: 10.1021/acsnano.5b00087. Epub 2015 Apr 14.

Abstract

We describe the synthesis and characterization of monolithic, ultralow density WS2 and MoS2 aerogels, as well as a high surface area MoS2/graphene hybrid aerogel. The monolithic WS2 and MoS2 aerogels are prepared via thermal decomposition of freeze-dried ammonium thio-molybdate (ATM) and ammonium thio-tungstate (ATT) solutions, respectively. The densities of the pure dichalcogenide aerogels represent 0.4% and 0.5% of full density MoS2 and WS2, respectively, and can be tailored by simply changing the initial ATM or ATT concentrations. Similar processing in the presence of the graphene aerogel results in a hybrid structure with MoS2 sheets conformally coating the graphene scaffold. This layered motif produces a ∼50 wt % MoS2 aerogel with BET surface area of ∼700 m(2)/g and an electrical conductivity of 112 S/m. The MoS2/graphene aerogel shows promising results as a hydrogen evolution reaction catalyst with low onset potential (∼100 mV) and high current density (100 mA/cm(2) at 260 mV).

摘要

我们描述了整体式、超低密度 WS2 和 MoS2 气凝胶，以及具有高表面积的 MoS2/石墨烯杂化气凝胶的合成和特性。通过冷冻干燥的硫钼酸铵（ATM）和硫钨酸铵（ATT）溶液的热分解分别制备了整体式 WS2 和 MoS2 气凝胶。纯二硫化物气凝胶的密度分别为 MoS2 和 WS2 完全密度的 0.4%和 0.5%，通过简单改变初始 ATM 或 ATT 浓度可以进行调整。在石墨烯气凝胶存在的情况下进行类似的处理，会得到一种具有 MoS2 片层在石墨烯支架上形成共形涂层的杂化结构。这种层状结构产生了一种具有约 700 m2/g 的 BET 表面积和约 112 S/m 的电导率的约 50wt% MoS2 气凝胶。MoS2/石墨烯气凝胶作为析氢反应催化剂具有低起始电位（约 100 mV）和高电流密度（在 260 mV 时为 100 mA/cm2）的优异性能。