Facet-Dependent Gas Adsorption Selectivity on ZnO: A DFT Study

Semiconductor-based gas sensors are of great interest in both industrial and research settings, but poor selectivity has hindered their further development. Current efforts including doping, surface modifications facet controlling have been proved effective. However, the “methods-selectivity” correlation is ambiguous because uncontrollable defects states during experiments. Here, as a case study, using DFT method, we studied adsorption features commonly tested gases—CH2O, H2, C2H5OH, CH3COCH3, NH3—on facets ZnO(0001¯), ZnO(101¯0) ZnO(101¯1). The energies charge transfers were calculated, was analyzed. results show ZnO(0001¯) obvious CH2O selectivity; slight to C2H5OH NH3; ZnO(101¯1) which agrees with experimental results. mechanism selective terms polarity, geometric matching electronic structure matching. attributed joint effort matching: former allows for specific gas/slab interactions, latter decides strength interactions. As sensing probably dominated by gas–lattice this work envisioned be helpful designing new material high selectivity.