Synthesis of functionalized mesoporous TiO2-SiO2 with organic fluoroalcohol as high performance DMMP gas sensor

Mesoporous TiO2-SiO2 functionalized with p-hexa-fluoroisopropanol aniline (HFIP) was designed and synthesized to achieve highly sensitive and selective sensing toward nerve agent simulant dimethyl methylphosphonate (DMMP) due to a hydrogen bonding between target DMMP and TiO2-SiO2-HFIP. The sensing experiments were conducted by coating compounds onto quartz crystal microbalance (QCM) transducers. It was found that the observed frequency shifts gradually and turned saturated in the range from 10 to 60 ppm. Gas sensing test results revealed that sensors had enhanced sensitivity due to the decoration of HFIP on TiO2-SiO2 in a ppb level. Furthermore, when the doping of HFIP reached 20 wt%, the sensors achieved the best sensing performance. In conclusion, the QCM sensor coated with mesoporous TiO2-SiO2-HFIP exhibited fast response, excellent reversibility and high selectivity to nerve agent stimulant DMMP vapor, implying that mesoporous TiO2-SiO2-HFIP may be a good candidate for sensing DMMP.