Evaluation of sensitivity, selectivity and stability of MOF and Zeolite functionalized resistive sensors, sensor arrays and pre-concentrators for the detection of VOCs mixtures

Abstract

Summarize → We synthesized Core shell composite structure of ZnO@ZIF-8 with tetrapodal morphology by solvothermal method. → We obtained MOF-coated 3D structure is selective towards H2 gas at 250°C and it also gives excellent UV response (about 195) at RT. → As we increases temperature in RT UV response decreases significantly and about to nullify at higher temperatures is attributed to no increase in minority charge carrier concentration at higher temperature by UV irradiation as due to thermal energy contribution conductivity of composite already increased. → We observed at 175°C sensor enters saturation unlike at RT. → The response and recovery time for UV response at 175°C comes out to be 10s and 102s respectively. → We observed at 250°C nanocomposite (2h) exhibits about 2.6 response value for H2. → We observed at RT, UV irradiation gives response value of about 265 for 4h coated nanocomposite. → Charged defects at the nanocomposite interface may be very reactive towards H2 and vanish. → Hence, selectivity towards H2 is attributed due to pore size of nanocomposite as other moieties don’t fit through these pores.