ABSTRACT
Salicylaldehyde rhodamine B hydrazone (SRBH) was developed as a new spectrofluorimetric probe for the selective and sensitive detection of CrO(4)(2-) in acidic conditions. The proposed method was based on the special oxidation reaction between non-fluorescent SRBH by potassium dichromate to produce a highly fluorescent rhodamine B, as a product. Under the optimum conditions described, the fluorescence enhancement at 591 nm was good linearly related to the concentration of CrO(4)(2-) from 1.0 x 10(-8) to 3.0 x 10(-7)M (0.42-12.6 ng mL(-1)) with a correlation coefficient of R(2)=0.9989 (n=10) and a detection limit of 1.5 x 10(-9)M (0.063 ng mL(-1)). The relative standard deviation (R.S.D.) was 2.0% (n=6). The proposed method was also successfully applied to the determination of chromium (VI) in drinking water, river water and synthetic samples.
Subject(s)
Biosensing Techniques/methods , Chromium Compounds/analysis , Chromium/analysis , Fluorescent Dyes/chemistry , Hydrazones/pharmacology , Chromium/chemistry , Chromium Compounds/chemistry , Environmental Monitoring/methods , Fluorescent Dyes/chemical synthesis , Fluorescent Dyes/pharmacology , Hydrazones/chemical synthesis , Hydrazones/chemistry , Models, Biological , Osmolar Concentration , Rhodamines/chemical synthesis , Rhodamines/chemistry , Rhodamines/pharmacology , Solubility , Time Factors , Water/chemistry , Water/pharmacology , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/isolation & purificationABSTRACT
Co9S8 nanocrystalline aggregations were synthesized in hydrazine hydrate (N2H4 x H2O) solvent at 180 degrees C for 12 h through a hydrothermal method using cobalt sulfate hydrate (CoSO4 x 7H2O) and sodium sulfate (Na2SO3) as the starting materials. The prepared samples were characterized using X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), and transmission electron microscope (TEM). FTIR spectrum was measured using Fourier-transform infrared spectrometer. The results showed that the products were mainly composed of Co9S8 hexagonal flakes, which were about 2.1 microm in diameter and 200 nm in thickness. The flakes consisted of Co9S8 nanocrystallites with an average size of 2.5 nm.
ABSTRACT
TiO2 nanocrystalline was prepared by a emulsion method in the mixed solvent of cyclohexane and acetic anhydride using, titanyl organic compound as the precursor. The prepared product was characterized by means of X-ray diffraction (XRD) and Fourier transform infrared spectrum (FTIR). The photocatalytic oxidation of methyl orange with TiO2 loaded with various metal ions was discussed. The spectral research results showed that the photocatalytic reaction of methyl orange with TiO2 loaded with Bi3+ was promoted, some metal ions caused almost no promotion of TiO2 oxidation of methyl orange, and Ni2+ and Fe3+ ions caused a little promotion. The best mass proportion of Bi3+ and TiO2 was defined as 1:8, which has a good photocatalytic activity. The photocatalytic degradation reaction of methyl orange was affected by the concentration of TiO2 nanocrystal, and when the mass proportion of Bi3+ and TiO2 is 1:8, the best photocatalytic activity concentration of TiO2 is about 1.6 g x L(-1).
Subject(s)
Metals/chemistry , Nanoparticles/chemistry , Spectroscopy, Fourier Transform Infrared , Titanium/chemistry , Azo Compounds/chemistry , Bismuth/chemistry , Catalysis/radiation effects , Cations/chemistry , Iron/chemistry , Nickel/chemistry , Oxidation-Reduction/radiation effects , Research Design , Ultraviolet Rays , X-Ray DiffractionABSTRACT
ZnO nanocrystal was prepared with Zn(CH3COO)2.2H2O and CO(NH2)2 as precursor by a solvothermal process. The products were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), and photoluminescence spectrum (PL). The results show that the ZnO nanocrystal has good characteristics, and the average particle size of the ZnO nanocrystal is about 17.2 nm. There is a broad PL peak for ZnO nanocrystal between 500-700 nm.
