The selective detection of harmful gases is of great significance to human health and air quality,triggering the need for special customizations of sensing material structure.In this study,we prepared a novel Sn S_(2)...The selective detection of harmful gases is of great significance to human health and air quality,triggering the need for special customizations of sensing material structure.In this study,we prepared a novel Sn S_(2)/black phosphorus(BP)two-dimensional(2D)-2D heterostructure via the in situ hydrothermal growth of Sn S_(2)nanosheets on exfoliated BP lamellae for NO_(2)sensing applications.In the Sn S_(2)/BP composite,the holes with high oxidizability in p-type BP could oxidize Sn^(2+)into Sn^(4+),thus inhibiting the formation of Lewis acidic S vacancies.This Sn^(2+)/Lewis acidity suppression of the composite was further confirmed by X-ray photoelectron spectroscopy and acidic double-layer capacitance analyses,and promoted the adsorption and detection of acidic NO_(2).Owing to its valence and Lewis acidity engineering,the Sn S_(2)/BP heterostructure sensor could detect trace levels of NO_(2)as low as 100 ppb(parts per billion)with high response,fast response/recovery,good stability,and selectivity at room temperature.The high absorption energy of NO_(2)(à0.74 e V),as indicated by the density functional theory calculations,suggests that NO_(2)was chemically adsorbed on the Sn S_(2)/BP surface,which was also evidenced by the in situ Raman spectroscopy results.This work opens up interesting opportunities for the rational design of highly efficient NO_(2)gas sensors through Lewis acidity modification and interface engineering.展开更多
A PANI/WO3@cotton thread-based flexible sensor that is capable of detecting NH3 at room temperature is developed here.A layer of WO3 with PANI nanoparticles can be deposited by in-situ polymerization.The morphology an...A PANI/WO3@cotton thread-based flexible sensor that is capable of detecting NH3 at room temperature is developed here.A layer of WO3 with PANI nanoparticles can be deposited by in-situ polymerization.The morphology and structure of the specimens were investigated by utilizing TEM,SEM,XRD and FTIR.The sensing performance of the PANI/WO3@cotton sensors with different WO3 molar ratios to NH3 at room temperature was examined.The results show that the optimal sensor(10 mol%WO3)has a response of 6.0 to 100 ppm NH3,which is significantly higher than that of the sensors based on pristine PANI and other composites.The PANI/WO3@cotton sensor also displays excellent selectivity,gas response,and flexibility even at room temperature.The unique fiber structure,p-n heterojunction,and the increased protonation of PANI in the composites contribute to the enhanced sensing property.展开更多
基金supported by the National Natural Science Foundation of China(51802252)Natural Science Foundation of Shaanxi Province(2020JM-032)+1 种基金Natural Science Foundation of Jiangsu Province(BK20180237)111 Project 2.0(BP0618008)。
文摘The selective detection of harmful gases is of great significance to human health and air quality,triggering the need for special customizations of sensing material structure.In this study,we prepared a novel Sn S_(2)/black phosphorus(BP)two-dimensional(2D)-2D heterostructure via the in situ hydrothermal growth of Sn S_(2)nanosheets on exfoliated BP lamellae for NO_(2)sensing applications.In the Sn S_(2)/BP composite,the holes with high oxidizability in p-type BP could oxidize Sn^(2+)into Sn^(4+),thus inhibiting the formation of Lewis acidic S vacancies.This Sn^(2+)/Lewis acidity suppression of the composite was further confirmed by X-ray photoelectron spectroscopy and acidic double-layer capacitance analyses,and promoted the adsorption and detection of acidic NO_(2).Owing to its valence and Lewis acidity engineering,the Sn S_(2)/BP heterostructure sensor could detect trace levels of NO_(2)as low as 100 ppb(parts per billion)with high response,fast response/recovery,good stability,and selectivity at room temperature.The high absorption energy of NO_(2)(à0.74 e V),as indicated by the density functional theory calculations,suggests that NO_(2)was chemically adsorbed on the Sn S_(2)/BP surface,which was also evidenced by the in situ Raman spectroscopy results.This work opens up interesting opportunities for the rational design of highly efficient NO_(2)gas sensors through Lewis acidity modification and interface engineering.
基金This work was supported by the National Natural Science Foundation of China(61471233).
文摘A PANI/WO3@cotton thread-based flexible sensor that is capable of detecting NH3 at room temperature is developed here.A layer of WO3 with PANI nanoparticles can be deposited by in-situ polymerization.The morphology and structure of the specimens were investigated by utilizing TEM,SEM,XRD and FTIR.The sensing performance of the PANI/WO3@cotton sensors with different WO3 molar ratios to NH3 at room temperature was examined.The results show that the optimal sensor(10 mol%WO3)has a response of 6.0 to 100 ppm NH3,which is significantly higher than that of the sensors based on pristine PANI and other composites.The PANI/WO3@cotton sensor also displays excellent selectivity,gas response,and flexibility even at room temperature.The unique fiber structure,p-n heterojunction,and the increased protonation of PANI in the composites contribute to the enhanced sensing property.