Wu Congyi, Zhang Jian, Wang Xiaoxia, Xie Changsheng, Shi Songxin, Zeng Dawen
State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China.
State Key Lab of Digital Manufacturing Equipment and Technology, Huazhong University of Science and Technology (HUST), Wuhan 430074, China.
Nanomaterials (Basel). 2019 Nov 16;9(11):1628. doi: 10.3390/nano9111628.
In this work, TiO QDs-modified NiO nanosheets were employed to improve the room temperature NO sensing properties of NiO. The gas sensing studies showed that the response of nanocomposites with the optimal ratio to 60 ppm NO was nearly 10 times larger than that of bare NiO, exhibiting a potential application in gas sensing. Considering the commonly reported immature mechanism that the effective charge transfer between two phases contributes to an enhanced sensitivity, the QDs sensitization mechanism was further detailed by designing a series of contrast experiments. First, the important role of the QDs size effect was revealed by comparing the little enhanced sensitivity of TiO particle-modified NiO with the largely enhanced sensitivity of TiO QDs-NiO. Second, and more importantly, direct evidence of the heterointerface charge transfer efficiency was detailed by the extracted interface bond (Ti-O-Ni) using XPS peak fitting. This work can thus provide guidelines to design more QDs-modified nanocomposites with higher sensitivity for practical applications.
在本工作中，采用TiO量子点修饰的NiO纳米片来改善NiO的室温NO传感性能。气敏研究表明，具有最佳比例的纳米复合材料对60 ppm NO的响应比裸NiO的响应大近10倍，在气敏方面展现出潜在应用。考虑到普遍报道的不成熟机制，即两相之间有效的电荷转移有助于提高灵敏度，通过设计一系列对比实验进一步详细阐述了量子点敏化机制。首先，通过比较TiO颗粒修饰的NiO灵敏度增强较小与TiO量子点修饰的NiO灵敏度大幅增强，揭示了量子点尺寸效应的重要作用。其次，更重要的是，利用XPS峰拟合提取的界面键（Ti-O-Ni）详细说明了异质界面电荷转移效率的直接证据。因此，这项工作可为设计更具灵敏度的量子点修饰纳米复合材料用于实际应用提供指导。
