Study Of Thiol Functionalized Gold Nanoparticles For Gas Sensor

As one of the air pollutants,volatile organic compounds(VOCs)have caused serious impacts on the atmospheric environment and human health.National and local governments have also put more and more stringent restrictions on VOC gas emissions,which has also put forward higher requirements for VOC gas detection.Therefore,it is of great significance to develop low-cost,high-response,highly portable VOC sensors for environmental monitoring.Nanogold is considered to be an excellent gas-sensitive material due to its high specific surface area and high surface plasticity.In this paper,two-phase synthesis of thiol-modified nanogold is used,and its gas-sensitive properties are tested by a gas-sensitive test platform.Nanogold was modified with different types of thiols,and its response and gas selectivity were studied.The principal component analysis method was used to test the ability of different nanogold sensors to distinguish different VOC gases.The main tasks include:Firstly,a two-phase method was used to synthesize a well-dispersed thiolmodified nano-gold,and a nanogold gas sensor was fabricated on the interdigitated electrode by drip coating to test its response to VOC gas.The gas sensitivity of the sensor is studied from different gas concentrations,different gas types,and different temperatures,and the response mechanism is analyzed.Studies have shown that there is a good linear relationship between response size and gas concentration,showing selectivity for different gas response differences,and temperature will have a certain irreversible effect on the sensor.Secondly,different types of thiols were used to modify nanogold,and the effect of different modifications on the gas sensing performance of the sensor was studied.The results show that the increase of alkyl mercaptan chain length can improve the response of nano-gold sensors to various VOC gases.The introduction of thiols containing different groups can change the sensor selectivity significantly.The stability of the sensor is improved by cross-linked nanogold.Finally,arrays of different modified nano-gold sensors were fabricated,and qualitative research was conducted on whether the sensor array can distinguish VOC gas by principal component analysis(PCA).The results of the study indicate that the sensor array can achieve VOC gas discrimination within the gas concentration range used in the experiment.