Detection of Trace Water Based on Electro-oxidation of Molybdenum Disulfide Nanomaterials to Form Molybdenum Oxysulfide.
Detection of Trace Water Based on Electro-oxidation of Molybdenum Disulfide Nanomaterials to Form Molybdenum Oxysulfide.
复制标题
DOI：
10.1021/acsami.2c02432
复制
发表时间：
2022-05
影响因子：
9.5
通讯作者：
Di Liu;Yixuan Bian;Zhiwei Zhu;Y. Shao;Meixian Li
中科院分区：
文献类型：
--
作者：
Di Liu;Yixuan Bian;Zhiwei Zhu;Y. Shao;Meixian Li
二硫化钼纳米材料由于其对许多电化学反应具有出色的催化性能，目前在电催化领域非常受欢迎。然而，二硫化钼纳米材料在正电位范围内的电化学氧化反应尚未得到深入研究。在此，我们研究了二硫化钼纳米材料的电氧化，并提出了一种新的反应机理：二硫化钼纳米材料与水发生电氧化，形成氧硫化钼（MoOS2）和氢离子，导致对电极上释放出氢气。采用接触角测量、扫描电子显微镜 (SEM)、透射电子显微镜 (TEM) 和能量色散 X 射线光谱 (EDS)、X 射线光电子能谱 (XPS)、X 射线吸收近边结构 (XANES) 光谱、飞行时间二次离子质谱 (ToF-SIMS) 和气相色谱 (GC) 等多种表征方法 用于证明氧的掺杂和氢的产生。基于该反应，我们构建了一种新型超灵敏电化学传感器，用于检测各种有机溶剂和离子液体中的痕量水，其最小可检测含量为0.0010%（v/v），与卡尔费休滴定法相当，但试剂更简单。
Molybdenum disulfide nanomaterials nowadays are very popular in electrocatalysis field due to their outstanding catalytic performance toward many electrochemical reactions. However, the electrochemical oxidation reaction of molybdenum disulfide nanomaterials in the range of positive potential has not been studied thoroughly. Herein, we have investigated electro-oxidation of molybdenum disulfide nanomaterials and put forward a new reaction mechanism: molybdenum disulfide nanomaterials are electro-oxidized with water to form molybdenum oxysulfide (MoOS2) and hydrogen ions, leading to the release of hydrogen on the counter electrode. Various characterization methods such as contact angle measurement, scanning electron microscope (SEM), transmission electron microscope (TEM) with energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge structure (XANES) spectroscopy, time-of-flight secondary ion mass spectrometry (ToF-SIMS), and gas chromatography (GC) were applied to attest the doping of oxygen and the generation of hydrogen. Based on this reaction, we constructed a novel ultrasensitive electrochemical sensor for detecting trace water with the minimum detectable content of 0.0010% (v/v) in various organic solvents and ionic liquids, which is comparable to the Karl Fischer titration, but with much simpler reagent.