Porous Zn O was obtained by hydrothermal method. The results of scanning electron microscope revealed the porous structure in the as-prepared materials. The acetone sensing test results of porous Zn O show that porous...Porous Zn O was obtained by hydrothermal method. The results of scanning electron microscope revealed the porous structure in the as-prepared materials. The acetone sensing test results of porous Zn O show that porous Zn O possesses excellent acetone gas sensing properties. The response is 35.5 at the optimum operating temperature of 320？C to 100 ppm acetone. The response and recovery times to 50 ppm acetone are 2 s and 8 s, respectively. The lowest detecting limit to acetone is 0.25 ppm, and the response value is 3.8. Moreover, the sensors also exhibit excellent selectivity and long-time stability to acetone.展开更多
La3＋ doped ZnO nano-rods with different doping concentration were prepared via solvothermal method.The doped ZnO nano-rods were characterized by X-ray diffraction（XRD） and scanning electron microscopy（SEM）,respec...La3＋ doped ZnO nano-rods with different doping concentration were prepared via solvothermal method.The doped ZnO nano-rods were characterized by X-ray diffraction（XRD） and scanning electron microscopy（SEM）,respectively.The effect of La3＋ doping on the gas-sensing properties was investigated.The results revealed that the sensor based on 6 mol% La3＋ doped ZnO nano-rods exhibited high response to dilute acetone,and the responses to 0.01×10-6 acetone reached 2.4 when operating at 425 ℃.The response time and the recovery time for 0.01×10-6 acetone were only 16 and 3 s,respectively.展开更多
ZnO has been studied intensely for chemical sensors due to its high sensitivity and fast response.Here,we present a simple approach to precisely control oxygen vacancy contents to provide significantly enhanced aceton...ZnO has been studied intensely for chemical sensors due to its high sensitivity and fast response.Here,we present a simple approach to precisely control oxygen vacancy contents to provide significantly enhanced acetone sensing performance of commercial ZnO nanopowders.A combination of H_(2)O_(2)treatment and thermal annealing produces optimal surface defects with oxygen vacancies on the ZnO nanoparticles(NPs).The highest response of~27,562 was achieved for 10 ppm acetone in 0.125 MH_(2)O_(2)treated/annealed ZnO NPs at the optimal working temperature of 400℃,which is significantly higher than that of reported so far in various acetone sensors based on metal oxide semiconductors(MOSs).Furthermore,first-principles calculations indicate that pre-adsorbed O formed on the surface of H_(2)O_(2)treated ZnO NPs can provide favorable adsorption energy,especially for acetone detection,due to strong bidentate bonding between carbonyl C atom of acetone molecules and pre-adsorbed O on the ZnO surface.Our study demonstrates that controlling surface oxygen vacancies by H_(2)O_(2)treatment and re-annealing at optimal temperature is an effective method to improve the sensing properties of commercial MOS materials.展开更多
基金Projected supported by the Project of Challenge Cup for College Students,China(Grant No.450060497053)
文摘Porous Zn O was obtained by hydrothermal method. The results of scanning electron microscope revealed the porous structure in the as-prepared materials. The acetone sensing test results of porous Zn O show that porous Zn O possesses excellent acetone gas sensing properties. The response is 35.5 at the optimum operating temperature of 320？C to 100 ppm acetone. The response and recovery times to 50 ppm acetone are 2 s and 8 s, respectively. The lowest detecting limit to acetone is 0.25 ppm, and the response value is 3.8. Moreover, the sensors also exhibit excellent selectivity and long-time stability to acetone.
基金supported by the project (No.KJ2009A098) sponsored by Education Department of Anhui Provincethe National Natural Science Foundation of China (No. 50975002)
文摘La3＋ doped ZnO nano-rods with different doping concentration were prepared via solvothermal method.The doped ZnO nano-rods were characterized by X-ray diffraction（XRD） and scanning electron microscopy（SEM）,respectively.The effect of La3＋ doping on the gas-sensing properties was investigated.The results revealed that the sensor based on 6 mol% La3＋ doped ZnO nano-rods exhibited high response to dilute acetone,and the responses to 0.01×10-6 acetone reached 2.4 when operating at 425 ℃.The response time and the recovery time for 0.01×10-6 acetone were only 16 and 3 s,respectively.
基金supported by the Technology Innovation Program(No.20013621,Center for Super Critical Material Industrial Technology)funded by the Ministry of Trade,Industry&Energy(MOTIE,Republic of Korea)the Priority Research Centers Program(2019R1A6A1A11055660)+2 种基金the Basic Science Research Program(2017 M3A9F1052297)through the National Research Foundation of Korea(NRF),funded by the Republic of Korean Government(Ministry of Science and ICT)the support from the International Energy Joint R&D Program of the Korea Institute of Energy Technology Evaluation and Planning(KETEP),granted financial resource from the Ministry of Trade,Industry&Energy,Republic of Korea(20208510010310)the support from the Basic Research in Science and Engineering Program of the NRF(2021R1A2C1013690)。
文摘ZnO has been studied intensely for chemical sensors due to its high sensitivity and fast response.Here,we present a simple approach to precisely control oxygen vacancy contents to provide significantly enhanced acetone sensing performance of commercial ZnO nanopowders.A combination of H_(2)O_(2)treatment and thermal annealing produces optimal surface defects with oxygen vacancies on the ZnO nanoparticles(NPs).The highest response of~27,562 was achieved for 10 ppm acetone in 0.125 MH_(2)O_(2)treated/annealed ZnO NPs at the optimal working temperature of 400℃,which is significantly higher than that of reported so far in various acetone sensors based on metal oxide semiconductors(MOSs).Furthermore,first-principles calculations indicate that pre-adsorbed O formed on the surface of H_(2)O_(2)treated ZnO NPs can provide favorable adsorption energy,especially for acetone detection,due to strong bidentate bonding between carbonyl C atom of acetone molecules and pre-adsorbed O on the ZnO surface.Our study demonstrates that controlling surface oxygen vacancies by H_(2)O_(2)treatment and re-annealing at optimal temperature is an effective method to improve the sensing properties of commercial MOS materials.
