Discrimination of 1‐ and 2‐Propanol by Using the Transient Current Change of a Semiconducting ZnFe2O4 Chemiresistor
Abstract
A semiconducting metal oxide (SMO) chemiresistor (ZnFe2O4) is used for discriminating two isomeric volatile organic compounds (VOCs), namely 1‐ and 2‐propanol. The transient current of the SMO chemiresistor is correlated with the aerobic oxidation of organic vapors on its surface. The changes in transient current of the ZnFe2O4 chemiresistor are measured at different temperatures (260–320 °C) for detecting equal concentrations (200 ppm) of the two structural isomers of propanol. The transient current of ZnFe2O4 reflects a faster oxidation of 2‐propanol than 1‐propanol on the surface. First‐principles calculations and kinetic studies on the interaction of 1‐ and 2‐propanol over ZnFe2O4 provide further insight in support of the experimental evidence. The calculations predict more spontaneous adsorption of 2‐propanol on the (111) surface of ZnFe2O4 than 1‐propanol. Kinetic parameters for the oxidation of isomeric vapors are estimated by modelling the transient current of ZnFe2O4 using the Langmuir‐Hinshelwood reaction mechanism. The faster oxidation of 2‐propanol and comparatively lower activation energy for the respective process over ZnFe2O4 is justified in accordance to the chemical structures of vapors. The findings have strong implications in exploring a new technique for discriminating isomeric VOCs, which is significant for environmental monitoring and medical applications.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 01, 2019
- Source ID
- 10.1002/cplu.201900036
Entities
People
- Abhishek Maikap
- Chinedu E. Ekuma
- K Mukherjee
- Mona E. Zaghloul
- Sina Najmaei
- Yangyang Zhao
Organizations
- Engineer Research and Development Center
- George Washington University
- Lehigh University
- Pandit Deendayal Energy University
- United States Army Research Laboratory