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Currently, the identification of sensing materials that can selectively and rapidly respond to hazardous gases is urgent for safeguarding the environment and human life. The adsorption of hazardous gas molecules (NO, NO 2 , SO 2 , CO, and H 2 S) on the GeSe monolayer doped with single main-group element atom is investigated and compared based on first-principles density functional theory (DFT). NO 2 has the highest adsorption energy and charge transfer adsorbed on both pristine GeSe and doped GeSe monolayer. At ambient temperature, for any doped GeSe monolayers adsorbing gas molecules (including H 2 O, O 2 , and N 2), the occupation function value of NO 2 is the highest. The analysis of density of states (DOS) and band structure indicates that NO 2 interacts with different modified GeSe monolayers in terms of atomic orbitals. Moreover, Al-GeSe has the largest change of work function before and after the adsorption of NO 2 , meaning that Al-GeSe has the greatest response to NO 2. current-voltage (I-V) characteristics demonstrate that Al-GeSe exhibits a remarkable current change after the adsorption of NO 2. These results illustrate that Al-GeSe has a strong physical and chemical interaction with NO 2 , yielding a high response and selectivity, which is anticipated to be the optimal gas sensing material for NO 2. [Display omitted] • Substituting one Ge atom with single main-group element atom (Al, Si, Sn, Ga and In) exhibits stable structures. • NO 2 shows significant physical and chemical interaction with doped GeSe monolayers by observing density of states, especially Al-GeSe. • The response of doped GeSe monolayers to NO 2 can be evaluated by observing work function and I-V characteristic. [ABSTRACT FROM AUTHOR]

Wearables and on-skin triboelectric nanogenerator (TENG) highly desire intrinsic stretchability, favorable permeability and waterproofness, fibers/textiles as one of the ideal substrates could meet the requirements. However, realizing the versatile integration of hydrophobic elastic fibers with electrodes remains a huge challenge. Herein, inspired by the sericin-bundled silk with outstanding stretchability, we develop a microfibers-membrane with omnidirectional superelasticity, permeability and superhydrophobicity (SPSM) by synchronous electrospinning of styrene-isoprene (SIS) block copolymers and electrospraying of the fluorinated SiO 2 nanoparticles. Co-solvent welding effect free of extra binders is proposed for the generation of in-situ anchored junctions between the SIS fibers, as well as achieving the anchoring effect for enhanced integration of SIS fiber-membranes with a variety of conductors such as sputtered gold (Au) layer, vacuum filtrated liquid metal-silver nanowires (LM-AgNWs) network and printed liquid metal-silver flakes-SIS (LM-AgFKs-SIS) ink, creating diverse elastic conductors and triboelectric-active-materials with optional advantages in mechanical stability, electrical robustness, triboelectric output and permeability. A self-cleaning SPSM-based single-electrode stretchable TENG (STENG) is demonstrated adaptive for tapping, stretching, bending and humidity, realizing a breathable self-powered sensor for materials identifying and hand posture monitoring. This work proposes a versatile superelastic fiber material competent for permeable STENGs and wearables with environment adaptivity. [Display omitted] • In-situ interlocked superelastic SIS microfibers with permeability and superhydrophobicity is realized free of extra binders. • Co-solvent in-situ anchoring effect enables integration of conductors with SPSM to realize mechanical/electrical robustness. • Permeable STENG as stretchable power source or self-powered sensor for materials identifying, posture monitoring is achieved. • Multifunctional SPSM promises as versatile substrate for multi-scenarios STENGs and wearables with environment adaptivity. [ABSTRACT FROM AUTHOR]

In the electrical industry, there are many hazardous gases that pollute the environment and even jeopardize human health, so timely detection and effective control of these hazardous gases is of great significance. In this work, the gas-sensitive properties of Pd-modified g-C 3 N 4 interface for each hazardous gas molecule were investigated from a microscopic viewpoint, taking the hazardous gases (CO, NO x) that may be generated in the power industry as the detection target. Then, the performance of Pd-modifiedg-C 3 N 4 was evaluated for practical applications as a gas sensor material. Novelly, an unconventional means was designed to briefly predict the effect of humidity on the adsorption properties of this sensor material. The final results found that Pd-modified g-C 3 N 4 is most suitable as a potential gas-sensitizing material for NO 2 gas sensors, followed by CO. Interestingly, Pd-modified g-C 3 N 4 is less suitable as a potential gas-sensitizing material for NO gas sensors, but has the potential to be used as a NO cleaner (adsorbent). Unconventional simulation explorations of humidity effects show that in practical applications Pd-modified g-C 3 N 4 remains a promising material for gas sensing in specific humidity environments. This work reveals the origin of the excellent properties of Pd-modified g-C 3 N 4 as a gas sensor material and provides new ideas for the detection and treatment of these three hazardous gases. [Display omitted] • The sensing properties of Pd-modified g-C 3 N 4 interface were evaluated for CO, NO x. • A new experiment for the prediction of humidity-influenced interface performance was designed. • This work enriches new schemes for the preparation of g–C 3 N 4 –based gas sensors. • This work provides new ideas for addressing hazardous gases generated in the electrical industry. [ABSTRACT FROM AUTHOR]

Using first-principles theory, we theoretically investigate the most stable doping site of Ni atom on pristine InN monolayer and adsorption behavior of Ni-doped InN (Ni-InN) monolayer upon four noxious gases (NO, CO 2 , H 2 S and NH 3). Electron localization function (ELF), electron deformation density (EDD) as well as density of state (DOS) are considered to further understand the adsorption behavior of Ni-InN monolayer towards gas molecules. For possible application of our proposed material, work function and band structure of the isolated and gas adsorbed Ni-InN monolayer are analyzed as well. It is found that the Ni dopant prefers to be adsorbed on the pristine InN monolayer at the T N site with the lowest biding force (E b) of −3.02 eV. Four gases could be stably adsorbed on the Ni-InN monolayer surface wherein the chemisorption is identified due to the large adsorption energy (E ad) and charge transfer (Q T). ELF, EDD and DOS analyses corroborate the strong chemical interaction between Ni dopant and activated atoms in gas molecules. The band structure analysis provides the sensing mechanism of Ni-InN based resistance-type chemical sensor for detection of such four gaseous species. Our calculations can supply some guidance to explore promising novel gas sensors using group III-V nitrides in the gas-sensing field and environmental monitoring fields. Unlabelled Image • The Ni-doping behavior on InN monolayer is elucidated to enrich the principle of TM-InN. • Adsorption and sensing behaviors of Ni- InN monolayer upon common pollutant gases were analyzed. • Our calculation can accelerate development of chemical sensors in environment monitoring and industrial manufacturing. [ABSTRACT FROM AUTHOR]

• C 4 F 7 N-N 2 gas mixture has great compatibility with heated aluminum. • Interaction between C 4 F 7 N-N 2 and copper cause gas decomposition and metal corrosion. • Accumulation of F, CF x and CN particles on the metal surface can be found. • Anti-corrosion treatment should be applied on the copper before application. The thermal interaction mechanism between C 4 F 7 N (fluorinated nitrile)-N 2 gas mixture using as substitute to SF 6 with metal was investigated. We found that interaction between C 4 F 7 N-N 2 and copper leads to surface corrosion or gas decomposition with interface temperature at 120℃-220℃. The oxidation of copper and accumulation of F, CF x and CN can be found and gaseous by-products such as C 3 F 6 , CF 3 H, C 3 F 6 O is produced. C 4 F 7 N-N 2 has better compatibility with aluminum than that of copper due to the existence of alumina. The interaction between C 4 F 7 N and alumina surface has the lowest adsorption energy, charge transfer compared with that of copper and aluminum. [ABSTRACT FROM AUTHOR]

Abstract Fluorinated nitrile (C 4 F 7 N) has received much attention as substitute gas for sulfur hexafluoride (SF 6) using in electrical equipment over the past two years. In this paper, we explored the compatibility between C 4 F 7 N and silver theoretically and experimentally. The interaction mechanism between C 4 F 7 N and silver was investigated based on the density functional theory (DFT) and the composition characteristics of C 4 F 7 N and silver after long term interaction were also revealed. It was found that the most energetically favorable adsorption structure has the adsorption energy of 0.69 eV with 0.024e charge transfer. Electron localization function (ELF) also shows evidently electron delocalization region between C 4 F 7 N and Ag (1 1 1). Thus the interaction mechanism belongs to physisorption and the van der Waals force plays a major role. The gas composition of C 4 F 7 N, the morphology and crystal structure of silver did not have any obvious change after 70 days' interaction, which indicates the compatibility between C 4 F 7 N and silver is great. Graphical abstract Image 1 Highlights • Composition of C 4 F 7 N and silver did not have any change after 70 days' interaction. • ELF shows evidently electron delocalization region between C 4 F 7 N and Ag (1 1 1). • Interaction between C 4 F 7 N and silver belongs to physisorption. • The use of silver is reliable for C 4 F 7 N gas insulated equipment. [ABSTRACT FROM AUTHOR]