Strain-Induced Band Modulation, Work Function, and QTAIM Analysis of Surface O-Functionalized Ti(2)C MXene

[Image: see text] Functionalized MXenes have wide applications in the fields of gas sensors, thermoelectric materials, and hydrogen storage. Strain-induced band engineering and the work function (WF) of Ti(2)CO(2) MXene are investigated theoretically. The calculations reveal that Ti(2)CO(2) MXenes are stable because of the negative E(coh), and all the strains considered are within the elastic limit. For Ti(2)CO(2) MXene, strain-induced blue shift of the Ti d state results in the transformation from a semiconductor to a metal. At about 4%, Ti(2)CO(2) MXene transforms from an indirect band gap to a direct band gap. The decreased WF induced by the strain improves the power efficiency of Ti(2)CO(2) MXene.