Hydrogen(H_(2))sensors are of great significance in hydrogen energy development and hydrogen safety monitoring.However,achieving fast and effective detection of low concentrations of hydrogen is a key problem to be so...Hydrogen(H_(2))sensors are of great significance in hydrogen energy development and hydrogen safety monitoring.However,achieving fast and effective detection of low concentrations of hydrogen is a key problem to be solved in hydrogen sensing.In this work,we combined the excellent gas sensing properties of tin(IV)oxide(SnO_(2))and zinc oxide(ZnO)with the outstanding electrical properties of reduced graphene oxide(rGO)and prepared palladium(Pd)-doped rGO/ZnO-SnO_(2)nanocomposites by a hydrothermal method.The crystal structure,structural morphology,and elemental composition of the material were characterized by FE-SEM,TEM,xRD,XPS,Raman spectroscopy,and N2 adsorption-desorption.The results showed that the Pd-doped ZnO-SnO_(2)composites were successfully synthesized and uniformly coated on the surface of the rGO.The hydrogen gas sensing performance of the sensor prepared in this work was investigated,and the results showed that,compared with the pure Pd-doped ZnO-SnO_(2)sensor,the Pddoped rGO/ZnO-SnO_(2)sensor modified with 3 wt%rGO had better hydrogen(H_(2))-sensing response of 9.4-100 ppm H_(2)at 380℃.In addition,this sensor had extremely low time parameters(the response time and recovery time for 100 ppm H_(2)at 380℃were 4 s and 8 s,respectively)and an extremely low detection limit(50 ppb).Moreover,the sensor exhibited outstanding repeatability and restoration.According to the analysis of the sensing mechanism of this nanocomposite,the enhanced sensing performance of the Pd-doped rGO/ZnO-SnO_(2)sensor is mainly due to the heterostructure of rGO,Zno,and SnO_(2),the excellent electrical and physical properties of rGO and the synergy between rGO and Pd.展开更多
Hydrogen sulfide(H_(2)S)detection remains a significant concern and the sensitivity,selectivity,and detection limit must be balanced at low temperatures.Herein,we utilized a facile solvothermal method to prepare Cu-do...Hydrogen sulfide(H_(2)S)detection remains a significant concern and the sensitivity,selectivity,and detection limit must be balanced at low temperatures.Herein,we utilized a facile solvothermal method to prepare Cu-doped SnO_(2)/rGO nanocomposites that have emerged as promising candidate materials for H_(2)S sensors.Characterization of the Cu-SnO_(2)/rGO was carried out to determine its surface morphology,chemical composition,and crystal defects.The optimal sensor response for 10 ppm H_(2)S was~1415.7 at 120℃,which was over 320 times higher than that seen for pristine SnO_(2)CQDs(R_(a)/R_(g)=4.4)at 280℃.Moreover,the sensor material exhibited excellent selectivity,a superior linear working range(R^(2)=0.991,1-150 ppm),a fast response time(31 s to 2 ppm),and ppb-level H_(2)S detection(R_(a)/R_(g)=1.26 to 50 ppb)at 120℃.In addition,the sensor maintained a high performance even at extremely high humidity(90%)and showed outstanding long-term stability.These superb H_(2)S sensing properties were attributed to catalytic sensitization by the Cu dopant and a synergistic effect of the Cu-SnO_(2)and rGO,which offered abundant active sites for O_(2)and H_(2)S absorption and accelerated the transfer of electrons/holes.展开更多
基金funded by the National Basic Research Program of China(grant No.2021YFB2012502)the National Science Foundation of China Project(grant numbers 62174163,61874121,61874012).
文摘Hydrogen(H_(2))sensors are of great significance in hydrogen energy development and hydrogen safety monitoring.However,achieving fast and effective detection of low concentrations of hydrogen is a key problem to be solved in hydrogen sensing.In this work,we combined the excellent gas sensing properties of tin(IV)oxide(SnO_(2))and zinc oxide(ZnO)with the outstanding electrical properties of reduced graphene oxide(rGO)and prepared palladium(Pd)-doped rGO/ZnO-SnO_(2)nanocomposites by a hydrothermal method.The crystal structure,structural morphology,and elemental composition of the material were characterized by FE-SEM,TEM,xRD,XPS,Raman spectroscopy,and N2 adsorption-desorption.The results showed that the Pd-doped ZnO-SnO_(2)composites were successfully synthesized and uniformly coated on the surface of the rGO.The hydrogen gas sensing performance of the sensor prepared in this work was investigated,and the results showed that,compared with the pure Pd-doped ZnO-SnO_(2)sensor,the Pddoped rGO/ZnO-SnO_(2)sensor modified with 3 wt%rGO had better hydrogen(H_(2))-sensing response of 9.4-100 ppm H_(2)at 380℃.In addition,this sensor had extremely low time parameters(the response time and recovery time for 100 ppm H_(2)at 380℃were 4 s and 8 s,respectively)and an extremely low detection limit(50 ppb).Moreover,the sensor exhibited outstanding repeatability and restoration.According to the analysis of the sensing mechanism of this nanocomposite,the enhanced sensing performance of the Pd-doped rGO/ZnO-SnO_(2)sensor is mainly due to the heterostructure of rGO,Zno,and SnO_(2),the excellent electrical and physical properties of rGO and the synergy between rGO and Pd.
基金This research was funded by the National Basic Research Program of China(2022YFB3206800,2021YFB2012500)the National Science Foundation of China Project(grant numbers 62174163,61874121,and 61874012).
文摘Hydrogen sulfide(H_(2)S)detection remains a significant concern and the sensitivity,selectivity,and detection limit must be balanced at low temperatures.Herein,we utilized a facile solvothermal method to prepare Cu-doped SnO_(2)/rGO nanocomposites that have emerged as promising candidate materials for H_(2)S sensors.Characterization of the Cu-SnO_(2)/rGO was carried out to determine its surface morphology,chemical composition,and crystal defects.The optimal sensor response for 10 ppm H_(2)S was~1415.7 at 120℃,which was over 320 times higher than that seen for pristine SnO_(2)CQDs(R_(a)/R_(g)=4.4)at 280℃.Moreover,the sensor material exhibited excellent selectivity,a superior linear working range(R^(2)=0.991,1-150 ppm),a fast response time(31 s to 2 ppm),and ppb-level H_(2)S detection(R_(a)/R_(g)=1.26 to 50 ppb)at 120℃.In addition,the sensor maintained a high performance even at extremely high humidity(90%)and showed outstanding long-term stability.These superb H_(2)S sensing properties were attributed to catalytic sensitization by the Cu dopant and a synergistic effect of the Cu-SnO_(2)and rGO,which offered abundant active sites for O_(2)and H_(2)S absorption and accelerated the transfer of electrons/holes.
