二维过渡金属硫化物纳米材料气敏特性及其传感器研究

High sensitivity, high selectivity gas sensing materials are needed for the future integrated, wireless, low energy consumption gas sensors.Transition metal dichalcogenides, such as molybdenum disulfide and tungsten disulfide, monolayers have caused much attention due to their interesting structure and properties analogous to graphene.While, the intrinsic semidonducting properties and tunable band-gap make two-dimentional transition metal dichalcogenides even better candidates for optoelectronic devices than graphenes，which stimulate us to work on the gas sensing performance and gas sensing mechanism of this promising material. We proposed to synthesize high quality molybdenum disulfide and tungsten disulfide nanosheets with controllable thickness by a chemical bath method,following with high temperature treatment in S containing gas flow. Protype gas sensors will be fabricated by depositing the nanosheets on the interdigitial electrodes. The gas sensing performance of the sensors will be tested by exposing to the gas pulse of donor or acceptor molcules with various functional chemical bond or electronic structure. Since the gas sensing properties are closely related to the material surface states,the gas sensing performance of the nanosheets with Pt nanoparticles loading will be investigated. To clarify the effect of oxygen species on the gas sensing behavior of the dichalcogenides, these materials will be characterized under both oxygen exhaust condition and oxygen rich condition. The gas sensing mechanism of the transition metal dichalcogenide nanosheets would be clarified by analyzing the gas sensing information obtained from different conditions. Considering the potential application of the molybdenum disulfide and tungsten disulfide nanosheets in the future wireless sensing network, the wireless gas sensors will be developed by integrating the nanosheets with the interdigitial electrodes of the LCR resonators.The gas sensing behavior of these passive wireless gas sensors will be investigated for a better understanding of the gas sensing mechanism of the two-dimensional transition metal dichalcogenide nanomaterials.

研究开发满足未来高灵敏度、高选择性、低功耗需求的高性能气敏材料及其传感器是气体传感器领域研究的重要课题。二维过渡金属硫化物纳米材料具有和石墨烯类似的结构，但其独特的元素组成、电子结构及表面化学键预示着该类材料是很有前景的新型气敏材料。本项目致力于二维过渡金属硫化物纳米材料气敏特性、气敏机理及其无线气体传感器的研究，将采用高温化学浴法制备不同厚度的二硫化钼、二硫化钨二维纳米材料；在材料可控制备的基础上系统研究不同条件下二硫化钼、二硫化钨二维纳米材料的气敏特性，不同表面性质对气敏响应的影响，以期阐明其气敏响应机理；通过把二维纳米材料与LCR谐振天线集成制备无线无源气体传感器，研究不同气体对传感器谐振频率的调谐规律及调谐机制，获得性能优化的传感器。本项目的研究将为二维过渡金属硫化物纳米材料在气体传感器领域应用奠定重要科学和技术基础。

二维纳米材料由于其大的体积/表面积比、独特的表面特性、优异的电学性能，非常适合气体传感器应用。本项目针对智能网络的发展对高性能无线无源气体传感器的需求，开展了二维硫化物纳米材料的制备、气敏特性的研究及无线气体传感器研究。采用高温化学浴法合成先后合成了二维(2D)二硫化锡(SnS2)、一硫化锡(SnS)纳米材料，发现反应介质中有机物的-NHR基团和-COOH基团的比例、反应温度及反应时间是控制产物形貌的核心参数；在二维SnS纳米材料的形成过程中，少量H2O的加入是生成黑磷结构SnS二维纳米材料的关键。系统研究可二维SnS2和SnS纳米材料的气敏响应特性，二维SnS2纳米材料对NO2气体有很好的气敏响应，检测限可以达到1 ppm以下，且对NO2有很好的选择性；二维SnS纳米材料对乙醇有优良的气敏响应和选择性，采用Pt纳米颗粒改性后，二维SnS纳米材料对乙醇的低温响应特性增强，但随工作温度的增加，气敏响应减弱，同时也发现Pt改性后二维SnS纳米材料对乙醇响应的选择性变差，这可能是由于Pt对有机分子基团都有很高的吸附活性所致。基于LTCC技术开发出了LC谐振天线，通过LC谐振天线与二维纳米材料的集成，研制出了基于LTCC技术的无线气体传感器，并获得了广泛关注，研究成果被欧盟COST-EUNETAIR国际合作团队作为亮点工作报导。该项目的研究为课题研究团队在2D纳米材料及无线集成传感器领域的进一步深入研究奠定了坚实基础。