Theoretical Study of Gas Sensing toward Acetone by a Single-Atom Transition Metal (Sc, Ti, V, and Cr)-Doped InP Monolayer.

Acetone (CHO) gas in the exhaled breath of diabetic patients can be used as an important biomarker for the painless and noninvasive diagnosis of diabetes mellitus. In this paper, based on the density functional theory (DFT), the adsorption behaviors of pristine and single-atom transition metal (X = Sc, Ti, V, and Cr)-doped InP surfaces (denoted as X-InP) toward CHO molecule were examined to explore the potential of these two-dimensional (2D) materials as a sensitive sensor for acetone gas. The calculation results indicate the unfavorable detection property for the pristine 2D-InP surface upon acetone with an unsatisfied gas response (12.4%). The introduction of a single-atom transition metal (Sc, Ti, V, and Cr) into the InP layer has significantly improved the adsorption capacity toward the CHO molecule. Owing to the high gas response values (-98.0%, 393.3%, and 393.3%), the Ti-InP, V-InP, and Cr-InP layers show their superiority in CHO detection at room temperature, in which Ti-InP achieves recycle use through heating at 698 K. Sc-InP is unsuitable for CHO sensing with a poor response (8.1%). Our work first gives a theoretical predication about the adsorption and sensitive detection performance of pristine and single-atom transition metal (Sc, Ti, V, and Cr)-doped InP upon acetone, which may provide an emerging kind of sensing material for the noninvasive diagnosis of diabetes mellitus indicated by acetone gas.