Adsorption of NO2 and H2S on ZnGa2O4(111) Thin Films: A First-Principles Density Functional Theory Study

Jen-Chuan Tung,Yi-Hung Chiang,Po-Liang Liu,Ding-Yuan Wang

doi:10.3390/app10248822

Jen-Chuan Tung, Yi-Hung Chiang + Show 2 more

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https://doi.org/10.3390/app10248822

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Abstract

We performed first-principles total-energy density functional calculations to study the reactions of NO2 and H2S molecules on Ga–Zn–O-terminated ZnGa2O4(111) surfaces. The adsorption reaction and work functions of eight NO2 and H2S adsorption models were examined. The bonding of the nitrogen atom from a single NO2 molecule to the Ga atom of the Ga–Zn–O-terminated ZnGa2O4(111) surfaces exhibited a maximum work function change of +0.97 eV. The bond joining the sulfur atom from a single H2S molecule and the Ga atom of Ga–Zn–O-terminated ZnGa2O4(111) surfaces exhibited a maximum work function change of −1.66 eV. Both results concur with previously reported experimental observations for ZnGa2O4-based gas sensors.

Highlights

IntroductionHousehold and industrial gas sensors are of great significance in artificial intelligence systems [1]
Household and industrial gas sensors are of great significance in artificial intelligence systems [1].several key problems and challenges persist in the development of sensing components.The sensor has an operating temperature that is too high for it to be used as a wearable device; wearable devices are subject to moisture, which weakens their sensing efficiency
To simulate the change of the work function with and without an NO2 or hydrogen sulfide (H2 S) molecule, we developed a supercell of ZnGa2 O4 along the (111) direction

Summary

Introduction

Household and industrial gas sensors are of great significance in artificial intelligence systems [1]. Liu et al, reported that Ga2 O3 nanowire gas sensors exhibit a reversible response to the oxidizing gases of O2 and reductive gas of CO in a working temperature range of 100–500 ◦ C [5]. Satyanarayana et al, reported that spinel ZnGa2 O4 films can be used to sense liquid petroleum gas (LPG) at temperatures ranging from 200 to 400 ◦ C. We developed adequate models for accurately predicting toxic NO2 oxidizing gases and H2 S reducing gases adsorbed on the ZnGa2 O4 (111) surface, which offer a detailed description of gas-sensing performance of the use of ZnGa2 O4 -based thin-film sensors, which may be probed experimentally using phenomenological techniques of sensor characterization such as chemical components, sensing layers, and surface modification by metal doping

Computational Details

Results and Discussion

Conclusions