Predicting gases sensing performance of α-MoO3 from nano-structural and electronic properties

• DOI: 10.1016/j.apsusc.2019.144913
• Publication Date: 2019-12-02T16:37:54Z
• Authors: Ke Xu; Ningbo Liao; Wei Xue; Hongming Zhou
• Keywords: 02 engineering and technology; 0210 nano-technology

Abstract MoO3 with α-phase (α-MoO3) is considered as one of the most promising gas sensing materials because of its thermodynamic stability and high sensitivity. In this work, the sensing performance of α-MoO3 toward H2, NO2, CH4, H2S, CO and NO gases molecules are investigated and predicted by DFT calculations. Based on calculated adsorption energies, density of states, charge transfer, bonding mechanism, and I-V relationship, MoO3 shows a significantly stronger sensitivity to H2, H2S, CH4 and NO2 than NO and CO. Furthermore, an approach is proposed to evaluate equivalent sensitivity of MoO3 by band gap difference, adsorption distance and charge transfer. The predicted sensitivities of MoO3 toward various gases are consistent with experimental results, demonstrating the validity and efficiency of the approach.