TY - JOUR
T1 - Large modulation of the chemical and electronic sensitization of TiO2/Ag/NiO nanostructure via in situ hydrothermal-induced heterointerface engineering
AU - Balamurugan, Chandran
AU - Cho, Kyusang
AU - Park, Byoungwook
AU - Kim, Jehan
AU - Kim, Nara
AU - Pak, Yusin
AU - Kong, Jaemin
AU - Kwon, Sooncheol
N1 - Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2022/2/15
Y1 - 2022/2/15
N2 - Chemical and electronic sensitization in metal oxide gas sensors are severely limited by poor dimension controls of metal oxide nanostructure and their electric/electronic properties. These limitations are overcome using hydrothermal-induced heterointerface engineering approaches. This work demonstrates that forming spherical titanium dioxide nanoparticles on a substrate significantly reduce a surface energy barrier of nucleation and induces novel mesophorous hierarchical TiO2 structure during hydrothermal synthesis, consequently increasing the surface area of the structure by ∼ 3 times compared to that of control. In addition, we succeeded in tailoring the energetics of hierarchical TiO2 nanosctructure by decorating with the nickel oxide and silver nanoparticles, which results in a desirable semiconductors/metal heterointerface for fast charge transfer where silver nanoparticles bridge nickel oxide and TiO2 nanostructure, and silver nanoparticles serve as preferential sites for chemisorption and migration of oxygen anions. The resulting heterostructure sensing properties such as sensitivity, limit of detection and selectivity are studied as a function of operating temperature (30–150 °C), relative humidity (RH) and various volatile organic analytes concentrations. The TiO2/Ag/NiO heterostructure finally exhibits a high gas response of ∼ 2.1 for acetone with a limit of detection of 34 ppb at 30 °C (or 21 ppb at 90 °C), and retains an excellent selectivity of acetone even at 90 % relative humidity. It exhibited a highly stable and speedy gas response for acetone toward various gases such as formaldehyde, ethanol, hydrogen sulfide, carbon monoxide even operating at 90 °C. Our results suggest a potential of constructed TiO2/Ag/NiO heterostructure for superior sensing volatile organic acetone and will also stimulate research on hetero-structured gas sensors with high sensitivity and selectivity.
AB - Chemical and electronic sensitization in metal oxide gas sensors are severely limited by poor dimension controls of metal oxide nanostructure and their electric/electronic properties. These limitations are overcome using hydrothermal-induced heterointerface engineering approaches. This work demonstrates that forming spherical titanium dioxide nanoparticles on a substrate significantly reduce a surface energy barrier of nucleation and induces novel mesophorous hierarchical TiO2 structure during hydrothermal synthesis, consequently increasing the surface area of the structure by ∼ 3 times compared to that of control. In addition, we succeeded in tailoring the energetics of hierarchical TiO2 nanosctructure by decorating with the nickel oxide and silver nanoparticles, which results in a desirable semiconductors/metal heterointerface for fast charge transfer where silver nanoparticles bridge nickel oxide and TiO2 nanostructure, and silver nanoparticles serve as preferential sites for chemisorption and migration of oxygen anions. The resulting heterostructure sensing properties such as sensitivity, limit of detection and selectivity are studied as a function of operating temperature (30–150 °C), relative humidity (RH) and various volatile organic analytes concentrations. The TiO2/Ag/NiO heterostructure finally exhibits a high gas response of ∼ 2.1 for acetone with a limit of detection of 34 ppb at 30 °C (or 21 ppb at 90 °C), and retains an excellent selectivity of acetone even at 90 % relative humidity. It exhibited a highly stable and speedy gas response for acetone toward various gases such as formaldehyde, ethanol, hydrogen sulfide, carbon monoxide even operating at 90 °C. Our results suggest a potential of constructed TiO2/Ag/NiO heterostructure for superior sensing volatile organic acetone and will also stimulate research on hetero-structured gas sensors with high sensitivity and selectivity.
KW - 3D-nanostructure
KW - Heterointerface engineering
KW - Heterometal oxide
KW - P-n junctions and Schottky barriers
KW - VOC sensing
UR - http://www.scopus.com/inward/record.url?scp=85116869298&partnerID=8YFLogxK
U2 - 10.1016/j.cej.2021.132690
DO - 10.1016/j.cej.2021.132690
M3 - Article
AN - SCOPUS:85116869298
SN - 1385-8947
VL - 430
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
M1 - 132690
ER -