SnS_(2) nanosheets decorated SnO_(2) hollow multishelled nanostructures for enhanced sensing of triethylamine gas

Highly sensitive,fast and low-temperature detection of triethylamine(TEA)gas based on SnO_(2) is attractive yet remains challenging.Herein,SnS_(2) nanosheets(NSs)/SnO_(2) hollow multishelled structures(HoMSs)-based sensors are designed by the synthesis of SnO_(2) HoMSs,followed by in situ sulfuration with thioacetamide.By varying the thioacetamide levels,Sn S_(2)/SnO_(2) heterostructures with different SnS_(2) contents were obtained and their TEA gas sensing performances were investigated.

Fabrication of porous Zn_(2)TiO_(4)-ZnO microtubes and analysis of their acetone gas sensing properties

Porous Zn2 Ti04-ZnO microtubes have been successfully fabricated using chemical precipitation followed by a calcination process using a carbon fiber template.The porous Zn_(2)TiO_(4)-ZnO micro tubes with a diameter of~4μm consisted of Zn_(2)TiO_(4) and ZnO nanoparticles.These displayed worm-like pore structures.Carbon fibers played an important role during the porous Zn_(2)TiO_(4)-ZnO microtube formation process.The porous and hollow structure of Zn_(2)TiO_(4)-ZnO provided abundant active sensing sites and channels for gas adsorption and diffusion.The porous Zn_(2)TiO_(4)-ZnO microtubes exhibited improved gas sensing properties for acetone when compared with pure ZnO.The Zn_(2)TiO_(4)-ZnO sensor response was 33.4 for 100μg·ml^(-1) acetone at the optimum operating temperature(370℃).This was~2.7 times higher than that of pure ZnO.Additionally,the as-prepared porous Zn_(2)TiO_(4)-ZnO microtubes displayed sufficient long-term acetone stability and selectivity.This showed the potential application for acetone detection.The enhanced Zn_(2)TiO_(4)-ZnO gas sensing properties are due to the unique heterogeneous and porous structure,which was analyzed using the porous and band structure.

NiO nanoparticles-decorated ZnO hierarchical structures for isopropanol gas sensing

In this paper,a three-dimensional(3D)hierar-chical ZnO structure consisting of nanosheets modified with ultrafine NiO particles was synthesized via a facile two-step chemical precipitate method.Various techniques characterized the as-synthesized ZnO/NiO composites and pure ZnO.The p-NiO/n-ZnO junctions formed between adjacent ZnO and NiO nanoparticles,improving the gas sensing performance.The ZnO/NiO composite with the Ni:Zn atomic ratio of 7.42:100 exhibited the best iso-propanol sensing properties.Compared to pure ZnO,it showed high selectivity and sensitivity(R_(a)/R_(g)=221.3 toward 400×10^(-6)isopropanol),fast response rate(less than 10 s),short recovery time,and simultaneously low operating temperature.Also,the ZnO/NiO composite exhibited a wide sensing range(1×10^(-6)-1000×10^(-6))to isopropanol and processed good long-term stability.The experimental results suggested the potential application in fabricating efficient isopropanol sensors using this ZnO/NiO composite.The enhanced isopropanol sensing mech-anism is also discussed in charge transfer between heterojunctions,surface area,and surface defects.