We report a type of micro-electro-mechanical system (MEMS) HS gas sensors with excellent sensing performance at the ppb level (lowest detection limit is 5 ppb). The sensors were fabricated with ZnO/CoO sensing materials derived from Zn/Co-MOFs by annealing at a suitable temperature of 500 °C. ZnO/CoO-500 exhibits the highest response when exposed to 10 ppb HS gas at 120 °C, and the response/recovery times are 10 s/21 s.
View Article and Find Full Text PDFIn this paper, the growth behavior of brain-like SnO microspheres synthesized by a tetrahydrofuran (THF) solvothermal method was studied. Unlike water or ethanol as the solvent, THF is a medium polar and aprotic solvent. Compared with other common polar solvents, the THF has no strong irregular effects on the growth process of SnO.
View Article and Find Full Text PDFTemplate-assisted synthesis strategy is an effective approach to prepare high performance oxygen reduction catalyst. The Fe-N/C catalysts were prepared via high temperature pyrolysis of the composites containing Fe-loaded mesoporous silica nanospheres and polypyrrole wrapped on it (Fe/mSiO@PPY). Fe loading ways combined with polymerization means of pyrrole greatly influence the structure and morphology of the final catalysts.
View Article and Find Full Text PDFMonodispersed Au nanoparticles in ordered mesoporous carbon/silica (Au/OMCS) nanocomposites were prepared by the solvent evaporation induced self-assembly. Au/OMCS nanocomposites were characterized through XRD, BET, and TEM. The obtained nanocomposites exhibit uniform mesopores with the size of 18 ± 2 nm.
View Article and Find Full Text PDFIn this study, an interface coassembly strategy is employed to rationally synthesize a yolk-shell CuO/silicalite-1@void@mSiO composite consisting of silicalite-1 supported CuO nanoparticles confined in the hollow space of mesoporous silica, and the obtained composite materials were used as a novel nonenzymatic biosensor for highly sensitive and selective detecting glucose with excellent anti-interference ability. The synthesis of CuO/silicalite-1@mSiO includes four steps: coating silicalite-1 particles with resorcinol-formaldehyde polymer (RF), immobilization of copper species, interface deposition of a mesoporous silica layer, and final calcination in air to decompose RF and form CuO nanoparticles. The unique hierarchical porous structure with mesopores and micropores is beneficial to selectively enrich glucose for fast oxidation into gluconic acid.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
January 2015
A hierarchical MFI zeolite, with typical micro/meso bimodal pore structures, was prepared by desilication method. CuO nanoparticles (NPs) were incorporated into the hierarchical MFI zeolite by impregnation method. CuO/hierarchical zeolite composites were characterized by X-ray diffraction, transmission electron microscopy and nitrogen sorption.
View Article and Find Full Text PDFVertically aligned cable-like CuO@Cu nanowires array was synthesized using a template-directed electrodeposition strategy. The morphology, crystal structure, and surface property of nanowires array were investigated by SEM, HRTEM, XRD, and XPS, respectively. It is found that the free standing namowires are highly dense, and possess about 20 μm in length and 200 nm in diameter.
View Article and Find Full Text PDFThis paper reports a nanomagnetic polyhedral oligomeric silsesquioxanes (POSS)-directing strategy toward construction of molecularly imprinted hybrid materials for antibiotic residues determination in milk samples. The imprinted polymeric layer was facilely obtained through the copolymerization of active vinyl groups present on the nanomagnetic POSS (Fe3O4@POSS) surface and functional monomer (methacrylic acid) binding with template (enrofloxacin). Herein, the octavinyl POSS acted as not only the building blocks for hybrid rigid architectures but also the cross-linker for the formation of effective recognition sites during the imprinting process.
View Article and Find Full Text PDFAn ordered mesoporous WO3 material with a highly crystalline framework was synthesized by using amphiphilic poly(ethylene oxide)-b-polystyrene (PEO-b-PS) diblock copolymers as a structure-directing agent through a solvent-evaporation-induced self-assembly method combined with a simple template-carbonization strategy. The obtained mesoporous WO3 materials have a large uniform mesopore size (ca. 10.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2013
Templated pores: A resol-assisted solvent-evaporation-induced self-assembly (RA-EISA) gives unique ordered mesoporous niobia spheres by using the amphiphilic diblock copolymer PEO-b-PS as a template. The mesoporous Nb2O5 spheres have ordered hexagonal structures, large pore size and high surface area, and a nanocrystalline framework. They show excellent electrochemical sensing of hydrogen peroxide.
View Article and Find Full Text PDFA functionalizable organosiliceous hybrid magnetic material was facilely constructed by surface polymerization of octavinyl polyhedral oligomeric silsesquioxane (POSS) on the Fe3O4 nanoparticles. The resultant Fe3O4@POSS was identified as a mesoporous architecture with an average particle diameter of 20 nm and high specific surface area up to 653.59 m(2) g(-1).
View Article and Find Full Text PDFThis study synthesized Fe(3)O(4) nanoparticles of 30-40nm by a sonochemical method, and these particles were uniformly dispersed on the reduced graphene oxide sheets (Fe(3)O(4)/RGO). The superparamagnetic property of Fe(3)O(4)/RGO was evidenced from a saturated magnetization of 30emu/g tested by a sample-vibrating magnetometer. Based on the testing results, we proposed a mechanism of ultrasonic waves to explain the formation and dispersion of Fe(3)O(4) nanoparticles on RGO.
View Article and Find Full Text PDFAn ordered mesoporous carbon material functionalized with carboxylic acid groups was synthesized. It was characterized by powder X-ray diffraction, transmission electron microscopy, Fourier transform IR spectroscopy and N(2) adsorption/desorption. Furthermore, this material was used to modify an electrode surface combined with a hydrophobic ionic liquid.
View Article and Find Full Text PDF