A dimethyl disulfide gas sensor based on nanosized Pt-loaded tetrakaidecahedral-FeOnanocrystals.

Surface modification by employing precious metals is one of the most effective ways to improve the gas-sensing performance of metal oxide semiconductors. Pure-FeOnanoparticles and Pt-modified-FeOnanoparticles were prepared sequentially using a rather simple hydrothermal synthesis and impregnation method. Compared with the original-FeOnanomaterials, the Pt--FeOnanocomposite sensor shows a higher response value (/ = 58.

Mesoporous TiCrN for trace HS detection with excellent long-term stability.

Efficient, accurate and reliable detection and monitoring of HS is of significance in a wide range of areas: industrial production, medical diagnosis, environmental monitoring, and health screening. However the rapid corrosion of commercial platinum-on-carbon (Pt/C) sensing electrodes in the presence of HS presents a fundamental challenge for fuel cell gas sensors. Herein we report a solution to the issue through the design of a sensing electrode, which is based on Pt supported on mesoporous titanium chromium nitrides (Pt/TiCrN).

Integrated sensing array of the perovskite-type LnFeO (Ln˭La, Pr, Nd, Sm) to discriminate detection of volatile sulfur compounds.

Distinguishing toxic gases among the various volatile sulfur compounds (VSCs) is of significant practical value for atmospheric and environmental pollution monitoring, industrial monitoring, and even for medical diagnostics (where VSCs are indicators of diseases). The particular challenge lies in the detection and discrimination of sulfur-containing gases such as dimethyl disulfide (DMDS), methyl sulfide (DMS), hydrogen sulfide (HS), and carbon disulfide (CS) is of value. Herein, single-phase perovskite-type LnFeO nanoparticles were prepared by the citrate sol-gel method.

Surface Functionalized Sensors for Humidity-Independent Gas Detection.

Semiconducting metal oxides (SMOXs) are used widely for gas sensors. However, the effect of ambient humidity on the baseline and sensitivity of the chemiresistors is still a largely unsolved problem, reducing sensor accuracy and causing complications for sensor calibrations. Presented here is a general strategy to overcome water-sensitivity issues by coating SMOXs with a hydrophobic polymer separated by a metal-organic framework (MOF) layer that preserves the SMOX surface and serves a gas-selective function.

Mesoporous WO modified by Au nanoparticles for enhanced trimethylamine gas sensing properties.

In this paper, KIT-6 is used as a template to prepare ordered mesoporous materials WO and Au-loaded WO (Au-WO). The pristine WO sensor and the Au-WO sensor are fabricated for the detection of 19 important gases, such as trimethylamine, formaldehyde and CS. The results show that the Au-WO sensor has better selectivity and higher response to TMA.

ZnO nanoflowers modified with RuO for enhancing acetone sensing performance.

Surface modification is a simple and effective means to promote the sensing performance of metal oxide semiconductor-based gas sensors. Marigold-shaped ZnO nanoflowers are fabricated via a simple precipitation reaction and subsequently catalytically modified with RuO on the surface through an ethylene glycol solvothermal treatment. The experimental results have proven that a very low content of Ru on the surface of ZnO exists in an oxidized state.

Oxygen-Defective Ultrathin BiVO Nanosheets for Enhanced Gas Sensing.

BiVO nanomaterials are potentially applicable in gas sensing, but the sensing performance is limited by the less active sites on the BiVO surface. In this work, we propose a strategy to improve the gas-sensing performance of BiVO by forming ultrathin nanosheets and introducing oxygen vacancies, which increase the surface active sites. Two-dimensional (2D) BiVO nanosheets with oxygen vacancies are prepared through a colloidal method with the assistance of nitric acid.

A dual emission nanocomposite prepared from copper nanoclusters and carbon dots as a ratiometric fluorescent probe for sulfide and gaseous HS.

A series of dual-emission fluorescent probes was prepared from copper nanoclusters (Cu NCs) and carbon dots (CDs). They show two emission peaks (blue at 469 nm and red at 622 nm) when photoexcited at 365 nm. Upon exposure to sulfide, the Cu NCs will be deteriorated because they react with sulfide to form CuS.

Hierarchical CoO@NiMoO core-shell nanowires for chemiresistive sensing of xylene vapor.

Hierarchical CoO@NiMoO core-shell nanowires (NWs) were synthesized utilizing a two-step hydrothermal method. The NWs show a high chemiresistive response (at a temperature of 255 °C) to xylene, with an R/R ratio of 24.6 at 100 ppm xylene, while the response towards toluene, benzene, ethanol, and acetone, CO, HS and NO is much weaker.

Manganese-doped zinc oxide hollow balls for chemiresistive sensing of acetone vapors.

Both pure and Mn(II)-doped ZnO hollow structures were synthesized by a solvothermal reaction, and their phase structures, morphologies and elemental composition were characterized. SEM and TEM observations show the pure ZnO and the Mn(II)-doped ZnO balls to possess similar hollow structure with a particle size of about 1.5 μm.

Aliovalent Fe(iii)-doped NiO microspheres for enhanced butanol gas sensing properties.

Fe-Doped NiO multi-shelled microspheres have been synthesized via a facile hydrothermal reaction. Various characterization techniques were introduced to investigate the structure and morphology of the as-prepared Fe-doped NiO multi-shelled microspheres. SEM and TEM observations showed that NiO microspheres are about 500 nm in diameter and with three shells.

Coordination Polymer-Derived Multishelled Mixed Ni-Co Oxide Microspheres for Robust and Selective Detection of Xylene.

Multishell, stable, porous metal-oxide microspheres (Ni-Co oxides, CoO and NiO) have been synthesized through the amorphous coordination polymer-based self-templated method. Both oxides of Ni and Co show poor selectivity to xylene, but the composite phase has substantial selectivity (e.g.

Designed formation through a metal organic framework route of ZnO/ZnCoO hollow core-shell nanocages with enhanced gas sensing properties.

The rational design of nanoscale metal oxides with hollow structures and tunable porosity has stimulated tremendous attention due to their vital importance for practical applications. Here, we report the designed synthesis of ZnO/ZnCoO hollow core-shell nanocages (HCSNCs) through a metal-organic framework (MOF) route. The strategy includes the synthesis of a zeolite imidazolate framework-8 (ZIF-8)/Co-Zn hydroxide core-shell nanostructure precursor and subsequent transformation to ZnO/ZnCoO HCSNCs by thermal annealing of the as-prepared precursor in air.

Mesoporous InN/In2O3 heterojunction with improved sensitivity and selectivity for room temperature NO2 gas sensing.

Establishing heterostructures is a good strategy to improve gas sensing performance, and has been studied extensively. In this work, mesoporous InN/In2O3 composite (InNOCs) heterostructures were prepared through a simple two-step strategy involving hydrothermal synthesis of In2O3 and subsequent nitriding into InN-composite In2O3 heterostructures. We found that the InN content has great influence on the resistance of InNOCs, and thus, the gas sensing performance.

Low Working-Temperature Acetone Vapor Sensor Based on Zinc Nitride and Oxide Hybrid Composites.

Transition-metal nitride and oxide composites are a significant class of emerging materials that have attracted great interest for their potential in combining the advantages of nitrides and oxides. Here, a novel class of gas sensing materials based on hybrid Zn3 N2 and ZnO composites is presented. The Zn3 N2 /ZnO (ZnNO) composites-based sensor exhibits selectivity and high sensitivity toward acetone vapor, and the sensitivity is dependent on the nitrogen content of the composites.

Preparation and ethanol sensing properties of In2O3 nanotubes.

In this paper, In2O3 nanotubes were prepared by an electrospinning method combined with an oriented-contract calcinations scheme, and characterized by differential thermal and thermal gravimetric analyzer (DTA-TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Ethanol sensing properties of the as-prepared nanotubes were investigated. The results showed that the In2O3 nanotubes were obtained at a fast heating rate of 100 degrees C/min.