Nanosized zero-valent iron (NZVI) supported on the cation exchange resin was synthesized and applied to decompose some water soluble azo dyes. The decomposition efficiency for azo dyes was evaluated by using the aqueo...Nanosized zero-valent iron (NZVI) supported on the cation exchange resin was synthesized and applied to decompose some water soluble azo dyes. The decomposition efficiency for azo dyes was evaluated by using the aqueous suspensions and parked column of this material. Batch experiments indicated that this novel material exhibited excellent degradation ability for 0.05 g·L1 of Acid Orange 7, Acid Orange 8, Acid Orange 10, Sunset Yellow, and Methyl Orange, with decolorization ratio up to 95% in 4 min; pH value was the key factor for degradation and H+ was one of the reactants; adsorption of azo dyes onto the material existed at the beginning but reduced gradually until disappearing completely. For the packed column system, 58%~90% of azo dyes were decomposed in the 1st circle of solution passing through the column, and the adsorption onto the materials could accelerate the degradation azo dyes with the increasing reaction time. During the degradation process, Fe2+, the product of NZVI, was exchanged to the resin again and could be reduced to Fe0 by KBH4 for reusing. The 10th refreshed NZVI possessed reductive activity up to 90% of the newly systhesized NZVI. Decomposing pollutants in the aqueous solution with columns packed with NZVI immobilized on the cation exchange resin is a promising technology that can solve the reclaiming and refreshing problem of NZVI.展开更多
Bandgap tuning using rare earth metals as dopants in ferrite-based photocatalytic materials has received a lot of interest because the Fermi 4f energy of these metals generates a sub-energy state in the bandgap genera...Bandgap tuning using rare earth metals as dopants in ferrite-based photocatalytic materials has received a lot of interest because the Fermi 4f energy of these metals generates a sub-energy state in the bandgap generated by the overlapping of Fe-3d and O-2p orbitals.Herein,dysprosium-doped cobalt-nickel mixed ferrite(D-CNFO)and its graphene-reinforced composite(D-CNFO@G)were prepared and an ideal photocatalyst material for azo dye mineralization was proposed.A cost-effective combination of wetchemical and ultrasonication methods was used to prepare the doped and composite samples.Advanced characterization methodologies were used to scrutinize the optical,compositional,structural,morphological,and photocatalytic characteristics of as-prepared materials.The X-ray diffraction analysis identified the spinel phase's(cubic)structure,while the electronic spectroscopy examination confirmed the prepared samples'rod-like morphology.The UV/visible absorbance spectrum shows the higher light harvesting behavior of the D-CNFO@G in the visible region.The mineralization performance of the DCNFO and D-CNFO@G composites was analyzed using Congo-red(an anionic dye),a well-known azo dye.The D-CNFO@G sample removes Congo-red dye at a rate almost 2.4%faster than the D-CNFO sample.The experiment involving trapping free radicals indicates that hydroxyl radical play s a crucial role in dye degradation.Since the D-CNFO@G catalyst is magnetic and can be isolated easily from the photocatalytic system,it shows an awkward cycle activity of more than 96%after five mineralization tests.The asprepared D-CNFO@G composite is proved as an excellent option for azo dye mineralization because of the combined impacts of rare earth doping,graphene reinforcement and nanotechnology.展开更多
The effect of interaction between liquid crystal （LC） and photoalignment material on the speed of optical rewriting process is investigated. The theoretical analysis shows that a smaller frank elastic constant K22 o...The effect of interaction between liquid crystal （LC） and photoalignment material on the speed of optical rewriting process is investigated. The theoretical analysis shows that a smaller frank elastic constant K22 of liquid crystal corresponds to a larger twist angle, which gives rise to a larger rewriting speed. Six different LC cells with the same boundary conditions （one substrate is covered with rubbed polyimide （PI） and the other with photo sensitive rewritable sulfuric dye I（SD1）） are tested experimentally under the same illumination intensity （450 nm, 80 mW/cm2）. The results demonstrate that with a suitable liquid crystal, the LC optical rewriting speed for e-paper application can be obviously improved. For two well known LC materials E7 （K22 is larger） and 5CB （K22 is smaller）, they require 11 s and 6 s corresponding to change alignment direction for generating image information.展开更多
Global solar radiation is recorded by fading of the colored film into which azo-dye is impregnated with use of organic solvent. Oil Red O, Sudan I, Sudan IV and Pyridylazonaphthol are used as the azo dye. These films ...Global solar radiation is recorded by fading of the colored film into which azo-dye is impregnated with use of organic solvent. Oil Red O, Sudan I, Sudan IV and Pyridylazonaphthol are used as the azo dye. These films can be applied to measure the solar radiation in many kinds of environmental or ecological conditions. The merits of the film compared with usual measurements are to be: unnecessary of any electric sources; cheap and mass-productive easily; suitable to integrate solar radiation for long time; easy dealing in out-door or underwater conditions; possible to use on leaves of any plants because of light weight; possible to use in a lot of points at the same time.展开更多
基金the National Natural Science Foundation of China (Grant No. 20537020)
文摘Nanosized zero-valent iron (NZVI) supported on the cation exchange resin was synthesized and applied to decompose some water soluble azo dyes. The decomposition efficiency for azo dyes was evaluated by using the aqueous suspensions and parked column of this material. Batch experiments indicated that this novel material exhibited excellent degradation ability for 0.05 g·L1 of Acid Orange 7, Acid Orange 8, Acid Orange 10, Sunset Yellow, and Methyl Orange, with decolorization ratio up to 95% in 4 min; pH value was the key factor for degradation and H+ was one of the reactants; adsorption of azo dyes onto the material existed at the beginning but reduced gradually until disappearing completely. For the packed column system, 58%~90% of azo dyes were decomposed in the 1st circle of solution passing through the column, and the adsorption onto the materials could accelerate the degradation azo dyes with the increasing reaction time. During the degradation process, Fe2+, the product of NZVI, was exchanged to the resin again and could be reduced to Fe0 by KBH4 for reusing. The 10th refreshed NZVI possessed reductive activity up to 90% of the newly systhesized NZVI. Decomposing pollutants in the aqueous solution with columns packed with NZVI immobilized on the cation exchange resin is a promising technology that can solve the reclaiming and refreshing problem of NZVI.
基金supported by Researchers Supporting Project(RSP2023R100),King Saud University,Riyadh,Saudi Arabiathe support provided by the Statutory City of Ostrava,Czechia through Research Grant"Global Experts"。
文摘Bandgap tuning using rare earth metals as dopants in ferrite-based photocatalytic materials has received a lot of interest because the Fermi 4f energy of these metals generates a sub-energy state in the bandgap generated by the overlapping of Fe-3d and O-2p orbitals.Herein,dysprosium-doped cobalt-nickel mixed ferrite(D-CNFO)and its graphene-reinforced composite(D-CNFO@G)were prepared and an ideal photocatalyst material for azo dye mineralization was proposed.A cost-effective combination of wetchemical and ultrasonication methods was used to prepare the doped and composite samples.Advanced characterization methodologies were used to scrutinize the optical,compositional,structural,morphological,and photocatalytic characteristics of as-prepared materials.The X-ray diffraction analysis identified the spinel phase's(cubic)structure,while the electronic spectroscopy examination confirmed the prepared samples'rod-like morphology.The UV/visible absorbance spectrum shows the higher light harvesting behavior of the D-CNFO@G in the visible region.The mineralization performance of the DCNFO and D-CNFO@G composites was analyzed using Congo-red(an anionic dye),a well-known azo dye.The D-CNFO@G sample removes Congo-red dye at a rate almost 2.4%faster than the D-CNFO sample.The experiment involving trapping free radicals indicates that hydroxyl radical play s a crucial role in dye degradation.Since the D-CNFO@G catalyst is magnetic and can be isolated easily from the photocatalytic system,it shows an awkward cycle activity of more than 96%after five mineralization tests.The asprepared D-CNFO@G composite is proved as an excellent option for azo dye mineralization because of the combined impacts of rare earth doping,graphene reinforcement and nanotechnology.
基金Project supported by the Science Foundation of Hong Kong University of Science and Technology (HKUST) (Grant Nos. CERG612208,CERG RPC07/08.EG01,CERG 612208/614408,CERG 612409,and CERG 612310)
文摘The effect of interaction between liquid crystal （LC） and photoalignment material on the speed of optical rewriting process is investigated. The theoretical analysis shows that a smaller frank elastic constant K22 of liquid crystal corresponds to a larger twist angle, which gives rise to a larger rewriting speed. Six different LC cells with the same boundary conditions （one substrate is covered with rubbed polyimide （PI） and the other with photo sensitive rewritable sulfuric dye I（SD1）） are tested experimentally under the same illumination intensity （450 nm, 80 mW/cm2）. The results demonstrate that with a suitable liquid crystal, the LC optical rewriting speed for e-paper application can be obviously improved. For two well known LC materials E7 （K22 is larger） and 5CB （K22 is smaller）, they require 11 s and 6 s corresponding to change alignment direction for generating image information.
文摘Global solar radiation is recorded by fading of the colored film into which azo-dye is impregnated with use of organic solvent. Oil Red O, Sudan I, Sudan IV and Pyridylazonaphthol are used as the azo dye. These films can be applied to measure the solar radiation in many kinds of environmental or ecological conditions. The merits of the film compared with usual measurements are to be: unnecessary of any electric sources; cheap and mass-productive easily; suitable to integrate solar radiation for long time; easy dealing in out-door or underwater conditions; possible to use on leaves of any plants because of light weight; possible to use in a lot of points at the same time.
