Oxygen deficient α-MoO₃ with enhanced adsorption and state-quenching of H₂O for gas sensing: a DFT study

Semiconducting oxides with reducible cations are ideal platforms for various functional applications in nanoelectronics and catalysts. Here we report an ultrathin monolayer alpha-MoO3 where tunable electronic properties different gas adsorbing behaviors upon introducing the oxygen vacancies (VO). The unique property of is that it contains three types atoms occupying Wyckoff sites absent other low-dimensional provides rich hybridized states. presence VO triggers intermediate state gap at ~0.59 eV below conduction band minimum reduces work function dramatically, together new excitations near infrared. realigned Fermi level associated dangling neighboring Mo affects adsorption thereafter. binding energy H2O molecules above 2.5 times up to -0.75 compared perfect lattice site trends transfer electrons also reverse. latter related shallow localized due adsorbed MoO3 which becomes quenched site. Those in-gap defective states deficient MoO3, broadening light absorption promoting uptake water, conductive application optoelectronics, photothermal therapy, sensor moisture.