Abstract
Understanding the effect of copper oxide (CuO)-decorated zinc oxide nanotube on carbon monoxide (CO) adsorption is crucial for designing a high-performance CO gas sensor. In this work, CO sensing properties of copper oxide-decorated zinc oxide (CuO-ZnO) nanotube are studied theoretically by employing first-principles density functional theory for the first time. The stability, adsorption mechanism, density of states, and change in electrical conductivity are studied. The results of calculating the adsorption energy show strong chemical adsorption of CO on CuO-ZnO nanotubes. The adsorption energy of CO on CuO-ZnO nanotube is calculated as 7.5 times higher than that on ZnO nanotube. The results of the Mulliken charge analysis reveal that electron transfer occurs from CO molecules to CuO-ZnO nanotubes. Additionally, the electrical conductivity of CuO-ZnO nanotubes significantly changes after adsorption of CO at room temperature. According to these studies, CuO-ZnO nanotube sensors can be used for the detection of CO gas. The results are in excellent agreement with the reported experimental results.
Highlights
Carbon monoxide (CO) is a highly toxic, colorless, odorless and tasteless gas
The results illustrated that compared to pristine Zinc oxide (ZnO) nanotube, CuO-decorated ZnO nanotube was more sensitive to CO molecules
It was found that CO prefers to be adsorbed on CuO-decorated ZnO (CuO-ZnO) nanotube with an excellent Ebind of − 4.76 eV
Summary
Carbon monoxide (CO) is a highly toxic, colorless, odorless and tasteless gas. CO is a byproduct of the incomplete burning of fossil fuels with insufficient oxygen [1]. Pristine ZnO-based gas sensors had a weak interaction with different gas molecules To solve this problem, some methods have been presented, including doping or decorating of impurity atoms, chemical functionalization, and introducing structural defects [23,24,25]. An et al [28] studied the adsorption of gas molecules on ZnO (6,0) single-walled nanotubes with and without oxygen vacancy. They showed that CO molecules form C − Zn bonds with a length of 2.67Å, an adsorption energy of -0.22 eV and 0.18 |e| charge transfer from the CO molecules to the nanotube. Charge transfer occurs between CO molecules and ZnO nanotube surface because of chemical adsorption
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
