Marikutsa Artem, Khmelevsky Nikolay, Rumyantseva Marina
Chemistry Department, Moscow State University, Vorobyovy Gory 1-3, 119234 Moscow, Russia.
LISM, Moscow State Technological University Stankin, Vadkovsky Ln. 1, 127055 Moscow, Russia.
Sensors (Basel). 2022 Aug 29;22(17):6520. doi: 10.3390/s22176520.
Benzene is a potentially carcinogenic volatile organic compound (VOC) and its vapor must be strictly monitored in air. Metal-oxide semiconductors (MOS) functionalized by catalytic noble metals are promising materials for sensing VOC, but basic understanding of the relationships of materials composition and sensors behavior should be improved. In this work, the sensitivity to benzene was comparatively studied for nanocrystalline -type MOS (ZnO, InO, SnO, TiO, and WO) in pristine form and modified by catalytic PtO nanoparticles. Active sites of materials were analyzed by X-ray photoelectron spectroscopy (XPS) and temperature-programmed techniques using probe molecules. The sensing mechanism was studied by in situ diffuse-reflectance infrared (DRIFT) spectroscopy. Distinct trends were observed in the sensitivity to benzene for pristine MOS and nanocomposites MOS/PtO. The higher sensitivity of pristine SnO, TiO, and WO was observed. This was attributed to higher total concentrations of oxidation sites and acid sites favoring target molecules' adsorption and redox conversion at the surface of MOS. The sensitivity of PtO-modified sensors increased with the surface acidity of MOS and were superior for WO/PtO. It was deduced that this was due to stabilization of reduced Pt sites which catalyze deep oxidation of benzene molecules to carbonyl species.
苯是一种潜在的致癌挥发性有机化合物（VOC），其蒸汽必须在空气中受到严格监测。由催化贵金属功能化的金属氧化物半导体（MOS）是用于检测VOC的有前途的材料，但对于材料组成与传感器行为之间关系的基本理解仍有待提高。在这项工作中，对原始形式以及经催化PtO纳米颗粒改性的纳米晶型MOS（ZnO、InO、SnO、TiO和WO）对苯的灵敏度进行了比较研究。使用探针分子通过X射线光电子能谱（XPS）和程序升温技术分析了材料的活性位点。通过原位漫反射红外（DRIFT）光谱研究了传感机制。在原始MOS和纳米复合材料MOS/PtO对苯的灵敏度方面观察到了明显的趋势。观察到原始SnO、TiO和WO具有更高的灵敏度。这归因于氧化位点和酸性位点的总浓度较高，有利于目标分子在MOS表面的吸附和氧化还原转化。PtO改性传感器的灵敏度随着MOS的表面酸度而增加，并且对于WO/PtO表现更优。据推断，这是由于还原的Pt位点的稳定化，其催化苯分子深度氧化为羰基物种。
