title: Comparative study on CO2 and CO sensing performance of LaOCl-coated ZnO nanowires.
abstract: Carbon dioxide (CO(2)) and carbon monoxide (CO) emissions from industries and combustion fuels such as coal, oil, hydrocarbon, and natural gases are increasing, thus causing environmental pollution and climate change. The selective detection of CO(2) and CO gases is important for environmental monitoring and industrial safety applications. In this work, LaOCl-coated ZnO nanowires (NWs) sensors are fabricated and characterized for the detection of CO(2) (250-4000 ppm) and CO (10-200 ppm) gases at different operating temperatures. The effects of the LaCl(3) coating concentration and calcination temperature of the sensors are studied. They are found to have a strong influence on the sensing performance to CO(2) gas, but a relatively slight influence on that to CO. The LaOCl coating enhances the response and shortens the response and recovery times to CO(2) compared with those to CO. The enhanced response of the LaOCl-coated ZnO NW sensors is attributed to the extension of the electron depletion layer due to the formation of p-LaOCl/n-ZnO junctions on the surfaces of the ZnO NWs.
authors.affiliation: International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST), No. 1 Dai Co Viet, Hanoi, Viet Nam. hieu@itims.edu.vn
authors.forename: Nguyen
authors.initials: N
authors.lastname: Van Hieu
authors.forename: Nguyen Duc
authors.initials: ND
authors.lastname: Khoang
authors.forename: Do Dang
authors.initials: do D
authors.lastname: Trung
authors.forename: Le Duc
authors.initials: le D
authors.lastname: Toan
authors.forename: Nguyen
authors.initials: N
authors.lastname: Van Duy
authors.forename: Nguyen Duc
authors.initials: ND
authors.lastname: Hoa
mesh_terms: D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D002245:Carbon Dioxide / Q000032:analysis* / Q000737:chemistry; D002248:Carbon Monoxide / Q000032:analysis* / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods; D007811:Lanthanum / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D000393:Air Pollutants; C028521:lanthanum chloride; D002245:Carbon Dioxide; D007811:Lanthanum; D002248:Carbon Monoxide; D015034:Zinc Oxide