•A facile and environmental friendly preparation method of rod-like In2O3 and Au/In2O3 nanomaterials was developed.•The In2O3 had no response to CO at room temperature, and the introduction of Au improved CO gas-sensing performance greatly.•Low working temperature favored the improvement of the response of Au/In2O3.Rod-like In2O3 nanomaterial was prepared under atmospheric pressure at 100 °C by using In(NO3)3 as In source. During the preparation process, HMTA provided alkaline environment, and was also acted as structure-directing agent to lead to the formation of rod-like structure. Rod-like Au/In2O3 was generated through in situ reduction of HAuCl4 by NaBH4. The pure In2O3 had no response to CO at room temperature (25 °C). The loading of the In2O3 with Au improved the gas-sensing performance greatly due to the abundant superficial adsorbed oxygen species. Low working temperature favored the improvement of the response. High annealing temperature led to the destruction of the rod-like structure and the growth of Au, resulting in the decrease of the response. Rod-like Au/In2O3 annealed at 300 °C had the best performance. The response to 100 ppm CO was about 9, and the response time and recovery time were all approximately 30 s. The stability and selectivity were good. Electron depletion layer principle was used to explain the discrepancy of responses for rod-like In2O3 and Au/In2O3.

•A simple hydrothermal method has been developed to obtain CeO2: Er/Yb.•The CeO2: Er/Yb nanocrystals present octahedral structure.•The upconversion fluorescence can be tuned with the doped concentration of Yb3+.•We studied the relationship of upconversion properties and calcination temperature.•The luminescence process can be explained as a typical of ET and GSA/ESA process.A simple hydrothermal method has been developed to obtain CeO2: Er/Yb nano-octahedra upconversion material, which converts near infrared to red, green and blue light. The effects of the doped concentration of Yb3+ and the calcination temperature on upconversion fluorescence performances have been studied by means of XRD, EDS, PL and XPS. The morphology and upconversion fluorescence can be tuned via increasing the doped concentration of Yb3+ and the calcining temperature.A simple hydrothermal method has been developed to obtain CeO2: Er/Yb nano-octahedra upconversion material, which converts near infrared to red, green and blue light. The morphology and upconversion fluorescence can be tuned via increasing the doped concentration of Yb3+ and calcining temperature.

The specific problem that is of concern here is to stop or at least significantly retard the diffusion of hazardous chemicals which are accidentally released into public places. The solution proposed is to employ rapidly gelling hydrogels that display an effective barrier property to cover the hazardous chemicals. Rapidly gelling hydrogels were prepared by blending a solution of polyvinyl alcohol (PVA) and borax. Sodium alginate (SA) was incorporated so as to improve the stretchability of the PVA–borax crosslinked system. The PVA–SA–borax hydrogels with PVA contents of 15 wt%, SA contents of 0.6 wt%, and borax:PVA ratios of 1:25 can be formed within 1 minute, which exhibited self-healing capability and favorable thermal adaptability. The barrier properties of the PVA–SA–borax hydrogels to sodium cyanide, dichlorvos and phorate were investigated, and more than 99% of the sodium cyanide, dichlorvos and phorate can be confined for 24 h by using 10 mm thick hydrogels.

Rare earth (Tm, Er, La, Yb and Ce)-doped In2O3 nanostructures with three-dimensionally ordered macroporous structures (3DOM) were prepared by a colloidal crystal templating method, and their ethanol sensing properties were investigated. Rare earth doping improved the gas response and lowered the optimum operating temperature. Tm-doped 3DOM In2O3 had the best gas-sensing performance, and the gas sensitivity for 100 ppm ethanol was seven times higher than that of pure 3DOM In2O3. The reason for the different sensitivities generated by the five doping elements and the underlying mechanism of the enhanced gas response for the samples were studied.

Au@ZnO yolk–shell nanostructures were synthesized by using Au@MOF-5 as a precursor. The morphological and structural properties of the products were characterized by XRD, SEM, TEM, TGA, XPS and UV-vis DRS. The morphology of the products could be tuned by the synthesis and calcination conditions. The acetone-sensing performance of the Au@ZnO yolk–shell nanostructures was investigated. The sensor based on Au@ZnO exhibited a high response (43 to 10 ppm acetone), low detection concentration of 50 ppb, excellent selectivity and short response/recovery time (15 s/12 s). The as-synthesized Au@ZnO has a promising application in acetone detection.

Au-loaded three-dimensional ordered macroporous In2O3 (Au-3DOM In2O3) was successfully prepared by a colloidal crystal template method, which exhibited high ethanol-sensing response and improved selectivity due to its unique skeleton structure and highly dispersed Au nanoparticles.

Two multifunctional sandwich-like mesoporous silica–graphene oxide (GO@mSiO2) and mesoporous silica–Fe3O4–graphene oxide (Fe3O4/GO@mSiO2) adsorbents were synthesized, and the adsorption equilibrium and kinetics of methylene blue on both of them were investigated. The structural and physical properties of the adsorbents were investigated by transmission electron microscopy, X-ray diffraction, vibrating magnetometry, nitrogen adsorption–desorption measurement and their chemical properties were analyzed by X-ray photoelectron spectroscopy, infrared spectroscopy, and Raman spectroscopy. GO@mSiO2 exhibited a high specific surface area of 634 m2 g−1 and its maximum adsorption capacity for methylene blue was 305.3 mg g−1. The specific surface and the maximum adsorption capacity were 179 m2 g−1 and 125.1 mg g−1 to Fe3O4/GO@mSiO2, which could be recycled by using an external magnetic field because of its magnetic property. Moreover, both adsorbents exhibited photothermal properties. A second-order kinetic equation could best describe the adsorption kinetics. Thermodynamic parameters indicated that the adsorption of methylene blue onto both adsorbents was thermodynamically feasible and could occur spontaneously.

Three-dimensionally ordered macroporous (3DOM) Pd–LaMnO3 self-regeneration catalysts were successfully prepared. After reduction treatment at 500 °C, the catalyst exhibited the best catalytic activity for methane combustion. The excellent catalytic performance was attributed to the ordered porous structure, the large surface area, and the strong interaction between segregated Pd and the LaMnO3 substrate.

Perovskite-type metal oxides have been regarded as promising materials for solar cells and catalysts. However, they suffer from a major challenge due to their low specific surface area. In this work, high specific surface area LaMO3 (M = Co, Mn) hollow spheres were synthesized by a hard template method. The influence of the reactant ratios on the properties of the products was investigated. The formation of La2O3, Co3O4 or MnO2 prevented the growth of LaMO3, which resulted in variations in the composition, morphology, specific surface area, surface chemistry and catalytic activity of the products. An acid washing process could remove La2O3 and Co3O4, which led to the enhancement of the specific surface area of LaCoO3. Due to the high reactant concentration and the slow heating rate, multishelled LaMnO3 hollow spheres with a high specific surface area of 42.6 m2 g−1 were formed, which showed the best catalytic activity in methane combustion.

Hierarchical flower-like and 1D tube-like ZnO architectures were synthesized by a microemulsion-based solvothermal method. Technologies of XRD, SEM and TEM were used to characterize the morphological and structural properties of the products. The influence of the flower-like and tube-like morphologies on their NO2 sensing properties was investigated. The experimental results showed that high-sensitivity NO2 gas sensors were fabricated. The sensitivity of the tube-like ZnO gas sensor was much higher than that of the flower-like ZnO gas sensor and the tube-like ZnO gas sensor exhibited shorter response time. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) technique was employed to investigate the NO2 sensing mechanisms. Free nitrate ions, nitrate and nitrite were the main adsorbed species during the adsorption, and NO also existed in the initial period of surface reoxidation. Furthermore, N2O was formed via NO− and N2O2− stemmed from NO and increased upon rising temperature. Moreover, the PL spectra and the XPS spectra further proved that the intensity of donors (oxygen vacancy (VO) and zinc interstitial (Zni)) and surface oxygen species (O2− and O2) involved in the gas sensing mechanism leaded to the different sensitivities.

An analytical method was developed using a solid phase extraction (SPE) cleanup and gas chromatography for detecting the residues of difenoconazole in Chinese cabbage and soil. The recovery and the relative standard deviation of this method in Chinese cabbage was 87.6–99.0%, 1.71–10.50%, respectively; in soil was 92.4–95.5%, 4.93–10.70%, respectively. Further degradation of difenoconazole residue in Chinese cabbage and soil was studied to evaluate residue behavior and environmental safety of difenoconazole. Degradation rate of difenoconazole in both Chinese cabbage and soil followed the first order kinetics with the half-lives of 6.6–7.8 and 54.2–55.0 days, respectively.

A graphite furnace atomic absorption spectrometry (GFAAS) method with optical temperature control for the determination of trace cadmium in paint samples is described. Optical temperature control was superior in many respects to current temperature control. The sensibility increased by 60%, the linear range widened by 60%, and the life of graphite tube showed a 200–300% increase because atomization temperature was lowered distinctly and atomization time was shortened. Use of lanthanum chloride as a matrix modifier was investigated. The linear range of calibration curve was 0–24 ng mL−1. The detection limit was 9.6 ng L−1. The characteristic mass was 3.0 pg. The method also resulted in excellent reproducibility (≤2.5% R.S.D.) at such low levels, and the recovery of added cadmium in paint samples was from 94.6% to 102%. This method is readily applicable to the determination of cadmium in paint samples.

Three-dimensionally ordered macroporous (3DOM) Pd–LaMnO3 self-regeneration catalysts were successfully prepared. After reduction treatment at 500 °C, the catalyst exhibited the best catalytic activity for methane combustion. The excellent catalytic performance was attributed to the ordered porous structure, the large surface area, and the strong interaction between segregated Pd and the LaMnO3 substrate.