TY - JOUR
T1 - Hollow spheres of CoCr2O4-Cr2O3 mixed oxides with nanoscale heterojunctions for exclusive detection of indoor xylene
AU - Kim, Bo Young
AU - Yoon, Ji Won
AU - Lim, Kyeorei
AU - Park, Sung Hyun
AU - Yoon, Ji Wook
AU - Lee, Jong Heun
N1 - Funding Information:
This work was supported by the Industrial Strategic Technology Development Program-Development of Miniaturized 10 mW TVOC/Alcohol Dual Gas Sensor and Module using Non-Silicon AAO Ceramic Substrate (Grant No. 10073068) funded by the Ministry of Trade, Industry & Energy (MOTIE, Korea) and a grant from the National Research Foundation of Korea (NRF), which was funded by the Korean government (Ministry of Education, Science, and Technology (MEST), Grant No. 2016R1A2A1A05005331), and the International Research & Development Program of the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (MSIT) of Korea (NRF-2017K1A3A1A49069947).
Publisher Copyright:
© The Royal Society of Chemistry.
PY - 2018
Y1 - 2018
N2 - As an effective alternative to simple binary oxide chemiresistors, polynary oxides with excellent tunability of the composition and hetero-interfaces are considered as promising material platforms for designing highly selective and sensitive gas sensors. In this study, ternary spinel CoCr2O4 hollow spheres and CoCr2O4-Cr2O3 mixed oxide hollow spheres were prepared via one-pot ultrasonic spray pyrolysis using solutions with different cation compositions (i.e., [Cr]/[Co] = 2, 3, and 4), and their gas-sensing characteristics were investigated. The pure CoCr2O4 hollow spheres exhibited an unusually high response to 5 parts per million (ppm) of p-xylene (ratio of resistance to gas and air = 61.4), with negligible cross-responses to 5 ppm of ethanol, toluene, benzene, trimethylamine, ammonia, formaldehyde, and carbon monoxide. When CoCr2O4-Cr2O3 hollow spheres with discrete Cr2O3 nanoclusters were formed using a spray solution with a [Cr]/[Co] ratio of 3, the xylene response was enhanced to 144.1, which allows the sensitive and selective detection of sub-ppm level p-xylene. The unprecedentedly high xylene selectivity and response in the present study are explained by the gas-accessible hollow morphology, the unique catalytic activity of the ternary and mixed oxides, and the enhanced chemiresistivity due to the formation of a heterojunction between CoCr2O4 and Cr2O3. The novel ternary oxide-based gas sensors with excellent xylene-sensing performance can be used in indoor air-monitoring applications.
AB - As an effective alternative to simple binary oxide chemiresistors, polynary oxides with excellent tunability of the composition and hetero-interfaces are considered as promising material platforms for designing highly selective and sensitive gas sensors. In this study, ternary spinel CoCr2O4 hollow spheres and CoCr2O4-Cr2O3 mixed oxide hollow spheres were prepared via one-pot ultrasonic spray pyrolysis using solutions with different cation compositions (i.e., [Cr]/[Co] = 2, 3, and 4), and their gas-sensing characteristics were investigated. The pure CoCr2O4 hollow spheres exhibited an unusually high response to 5 parts per million (ppm) of p-xylene (ratio of resistance to gas and air = 61.4), with negligible cross-responses to 5 ppm of ethanol, toluene, benzene, trimethylamine, ammonia, formaldehyde, and carbon monoxide. When CoCr2O4-Cr2O3 hollow spheres with discrete Cr2O3 nanoclusters were formed using a spray solution with a [Cr]/[Co] ratio of 3, the xylene response was enhanced to 144.1, which allows the sensitive and selective detection of sub-ppm level p-xylene. The unprecedentedly high xylene selectivity and response in the present study are explained by the gas-accessible hollow morphology, the unique catalytic activity of the ternary and mixed oxides, and the enhanced chemiresistivity due to the formation of a heterojunction between CoCr2O4 and Cr2O3. The novel ternary oxide-based gas sensors with excellent xylene-sensing performance can be used in indoor air-monitoring applications.
UR - http://www.scopus.com/inward/record.url?scp=85055212798&partnerID=8YFLogxK
U2 - 10.1039/c8tc04166k
DO - 10.1039/c8tc04166k
M3 - Article
AN - SCOPUS:85055212798
VL - 6
SP - 10767
EP - 10774
JO - Journal of Materials Chemistry C
JF - Journal of Materials Chemistry C
SN - 2050-7526
IS - 40
ER -