Theoretical Study of Gas Sensing toward Acetone by a Single-Atom Transition Metal (Sc, Ti, V, and Cr)-Doped InP3 Monolayer

Acetone (C3H6O) 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 InP3 surfaces (denoted as X-InP3) toward C3H6O 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-InP3 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 InP3 layer has significantly improved the adsorption capacity toward the C3H6O molecule. Owing to the high gas response values (-98.0%, 393.3%, and 393.3%), the Ti-InP3, V-InP3, and Cr-InP3 layers show their superiority in C3H6O detection at room temperature, in which Ti-InP3 achieves recycle use through heating at 698 K. Sc-InP3 is unsuitable for C3H6O 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 InP3 upon acetone, which may provide an emerging kind of sensing material for the noninvasive diagnosis of diabetes mellitus indicated by acetone gas.

Physisorption Behaviors of Organochlorine Pesticides on the InP3 Monolayer from Theoretical Insight

Dichlorodiphenyltrichloroethane (DDT), hexachlorocyclohexane (BHC), aldrin, and chlordimeform are ubiquitous organochlorine pesticide (OCP) residues in the environment, which pose a great threat to human health and ecosystems due to their high toxicity and easy accumulation. Based on the density functional theory (DFT) calculations, a two-dimensional InP3 monolayer was selected as a sensing material to study the sensitivity detection and adsorption behaviors toward BHC, aldrin, chlordimeform, and DDT. The calculation results show that four pesticide molecules are adsorbed on the InP3 surface by physical interaction. The identified response values (69.1, -43.1%) for DDT and chlordimeform reveal the potential of the InP3 monolayer as a sensing material for the detection of these two pesticides, accompanied by the achievement of cyclic utilization by heating to 498 K. The most satisfactory result is the adsorption of BHC, owing to the admirable sensing response (62.7%) and short recovery time (1.8 s) at room temperature, which makes InP3 a promising pesticide sensor for BHC. However, the InP3 surface is unsuitable for aldrin sensing due to poor response (-1.9%). Our work gives theoretical insight into the good sensitivity and recycling of the InP3 monolayer as a new pesticide sensor to detect DDT, BHC, and chlordimeform, which further broadens the application prospect of the InP3 nanosheet into the sensitive detection of organochlorine pesticides in the ecological environment.

Recent Advances in 2D Layered Phosphorous Compounds

2D layered phosphorous compounds (2D LPCs) have led to explosion of research interest in recent years. With the diversity of valence states of phosphorus, 2D LPCs exist in various material types and possess many novel physical and chemical properties. These properties, including widely adjustable range of bandgap, diverse electronic properties covering metal, semimetal, semiconductor and insulator, together with inherent magnetism and ferroelectricity at atomic level, render 2D LPCs greatly promising in the applications of electronics, spintronics, broad-spectrum optoelectronics, high-performance catalysts, and energy storage, etc. In this review, the recently research progress of 2D LPCs are presented in detail. First, the 2D LPCs are classified according to their elemental composition and the corresponding crystal structures are introduced, followed by their preparation methods. Then, the novel properties are summarized and the potential applications are discussed in detail. Finally, the conclusion and perspective of the promising 2D LPCs are discussed on the foundation of the latest research progress.

The novel two-dimensional photocatalyst SnN3 with enhanced visible-light absorption for overall water splitting

Herein, we proposed a novel excellent two-dimensional photocatalyst, the SnN₃ monolayer, using first-principles calculations. The stability of the SnN₃ monolayer was examined via formation energy, phonon spectroscopy and ab initio molecular dynamics simulations. The SnN₃ monolayer has an ultra-high optical absorption capacity of the order of 10⁵ cm^-1 in the visible region, which is 3, 4 and 10 times those of SnP₃, MoS₂ and g-C₃N₄ monolayers, respectively. Moreover, it has a higher carrier mobility, 769.19 cm² V^-1 s^-1, than the other monolayers; the available electrostatic potential of -5.02 eV and the appropriate band gap of 1.965 eV indicate its applicability as a catalyst for overall water splitting over a wide strain range. The electronic properties of the SnN₃ monolayer could also be engineered effectively by altering the external strain and electric field.