Surface State Regulation Of Metal Sulfide Semiconductor And Its Application In Ozone Detection

The most important gas sensors for monitoring gaseous pollutants such as ozone?O₃?and nitrogen dioxide?NO₂?are sensor arrays.The three key factors affecting the selectivity of semiconductor gas sensors include specific adsorption,surface conditions?adsorption sites,reaction sites,oxidation activity,acid-base properties,etc.?and selective improvement strategies?base material screening,loading and doping,surface modification,operating temperature control,etc.?Metal sulfide semiconductors have very low surface state densities and are very sensitive to changes in surface electrical properties,and have the potential as highly sensitive resistive gas sensors.Therefore,we will improve the recognition function and sensitivity of semiconductors by using Zn²⁺doped MoS₂ ultrathin nanosheets?UNs?and surface modification of MoS₂ UNs to develop different responses and a chemical-inductive sensor array that recognizes patterns of different analytes.?1?1 mmol of ammonium molybdate and 30 mmol of thiourea are dissolved in35 mL of distilled water,and 0,0.01,0.03,0.05,0.09,and 0.15 mmol of zinc acetate are added respectively,and the Zn²⁺doping tailored MoS₂ ultrathin nanosheets is prepared by the hydrothermal method.MoS₂ UNs,A thin brush was used to coat the paste of the MoS₂ UNs on a ceramic substrate to form a sensing film,and a sensor based on MoS₂ UNs is fabricated.Through the study,it was found that the response of the 5%Zn²⁺containing MoS₂ sensor to the five analytes of O₃ and NO₂ increased by more than 160%compared with the pure MoS₂ sensor,indicating that the Zn²⁺doping was successfully adapted to the sensing performance of the MoS₂ substrate.A versatile sensor array is constructed by doping different metal ions and changing their doping amount in MoS₂.In addition,the detection limits of O₃ and NO₂ for the MoS₂sensor containing 5%Zn²⁺were 17 and 215 ppb,respectively.The sensor array can identify O₃,NO₂,and other analytes in 14 seconds in real-world assays.?2?1 mmol of ammonium molybdate and 30 mmol of thiourea are made into MoS₂ UNs,followed by 0.1 mmol/L of S1-4?Note:S1-L-cysteine,S2-DL-Lysine,S3-N?-trifluoroacetyl-L-lysine,and S4-8-hydroxyquinoline?were uniformly mixed to obtain surface modified MoS₂ ultrathin nanosheets?UNs?respectively.Finally,a MoS₂ UNs sensor array was fabricated.Through the detection of O₃,C₂H₆O,CH₂O,and N₂-NO₂ gases,it was found that the response of different sensors to the same target gas changes significantly with the participation of different drugs in the surface modification.The same sensor responds to different target gases.The change of response is larger,indicating that the doping of S1-4 has obvious cutting effect and good discrimination performance on the sensing performance of MoS₂ UNs.