A new Zr-substituted polyoxometalate（POM） [（CH3）4N]6H2Cs2（H2O）4[Zr2（μ2-OH）2（α-SiW11O39）2]·27H2O（1） was prepared by the reaction of K10[A-α-SiW9O（34）]·25H2O with ZrCl4 in 0.5 mol/L NaAc-HAc（...A new Zr-substituted polyoxometalate（POM） [（CH3）4N]6H2Cs2（H2O）4[Zr2（μ2-OH）2（α-SiW11O39）2]·27H2O（1） was prepared by the reaction of K10[A-α-SiW9O（34）]·25H2O with ZrCl4 in 0.5 mol/L NaAc-HAc（Ac = CH3COO^-） buffer solution（pH = 4.5）. 1 was characterized by elemental and thermogravimetric analyses, powder X-ray diffraction and single-crystal X-ray diffraction. The title compound crystallizes in monoclinic system, space group P21/m with a = 13.1865（16）, b = 20.964（3）, c = 21.432（3） A^°, V = 5923.9（12） A^°3, Z = 2, Dc = 3.833 mg/m^3, μ = 22.175 mm^-1, F（000） = 6116, the final R = 0.0697 and wR = 0.1959 for 10319 observed reflections with I 〉 2σ（I）. Single-crystal X-ray structure analysis reveals that 1 exhibits a one-dimensional chain structure based on sandwiched-type POM anions [Zr2（μ2-OH）2（α-SiW11O（39））2]^10- linked by Cs＋cations. In addition, catalytic tests indicate that 1 provides a sufficient driving force for the conversion from thioethers to sulfoxides/sulfones by H2O2.展开更多
Different preparation routes for TiO_(2)-supported natural and synthetic clinoptilolite(TiO_(2)/CP)composites were thoroughly investigated on the basis of sol-gel,hydrothermal,and in-situ hydrothermal methods.The micr...Different preparation routes for TiO_(2)-supported natural and synthetic clinoptilolite(TiO_(2)/CP)composites were thoroughly investigated on the basis of sol-gel,hydrothermal,and in-situ hydrothermal methods.The micro-structural features and physicochemical properties of resultant TiO_(2)/CPs were characterized via X-ray diffraction patterns,scanning(transmission)electron microscope images,Fourier transform infrared spectra,inductively coupled plasma-optical emission spectrometry methods,BET-isotherms,UV-visible spectra,and surface charge potential distributions.The results showed that in-situ hydrothermal method led to well dispersions of loaded-TiO_(2) particles on the surface of leaf-like CP,while obviously aggregated TiO_(2) on a relatively distorted structure of CP was obtained using sol-gel and hydrothermal methods.Their adsorptive and photocatalytic efficiencies for removal of crystal violet(CV)dye in aqueous solution were also explored under UV-irradiations.The results demonstrated that TiO_(2)/CPs synthesized via sol-gel and in-situ hydrothermal methods presented the excellent performances with 98% removal efficiencies as compare to the bare commercial TiO_(2) which achieved 53%removal of CV dye.While,the in-situ hydrothermally synthesized TiO_(2)/CPs were the best due to their moderate energy cost,highest adsorption capacities and removal efficiencies.Particularly,the synthetic CPs as supports exhibited synergetic photocatalytic activities for the degradation of CV dye,which is attributed to their high surface areas,better adsorption capability,and fine dispersion of TiO_(2) particles.Adsorption and degradation kinetics of CV dye were found to follow the pseudo-second and pseudo-first order models,respectively.展开更多
水热体系下合成了新型层状UZM-8沸石,采用~13C交叉极化魔角旋转核磁共振(~13C CP MAS NMR)谱研究了该体系下二甲基二乙基氢氧化铵(DEDMAOH)的模板导向作用。研究结果表明,DEDMA^+与沸石发生较强的相互作用,处于沸石的不同化学环境中,起...水热体系下合成了新型层状UZM-8沸石,采用~13C交叉极化魔角旋转核磁共振(~13C CP MAS NMR)谱研究了该体系下二甲基二乙基氢氧化铵(DEDMAOH)的模板导向作用。研究结果表明,DEDMA^+与沸石发生较强的相互作用,处于沸石的不同化学环境中,起到了较强的模板导向作用。采用XRD和SEM方法对合成的UZM-8沸石进行了表征,考察了晶种和Na^+对UZM-8沸石的形成及结构的影响。实验结果表明,当n(DEDMA^+)∶n(SiO_2)<0.3时,合成体系中UZM-8沸石无法自发结晶,而当体系中存在Na^+和晶种时,n(DEDMA^+)∶n(SiO_2)=0.1时仍可合成出UZM-8沸石,且合成产物UZM-8沸石的结晶度提高,晶化时间缩短。展开更多
基金supported by the National Natural Science Foundation of China(No.21401195,21671040)the Natural Science Foundation for Young Scholars of Fujian Province(2015J05041)the Open Foundation of State Key Laboratory of Structural Chemistry(20160020)
文摘A new Zr-substituted polyoxometalate（POM） [（CH3）4N]6H2Cs2（H2O）4[Zr2（μ2-OH）2（α-SiW11O39）2]·27H2O（1） was prepared by the reaction of K10[A-α-SiW9O（34）]·25H2O with ZrCl4 in 0.5 mol/L NaAc-HAc（Ac = CH3COO^-） buffer solution（pH = 4.5）. 1 was characterized by elemental and thermogravimetric analyses, powder X-ray diffraction and single-crystal X-ray diffraction. The title compound crystallizes in monoclinic system, space group P21/m with a = 13.1865（16）, b = 20.964（3）, c = 21.432（3） A^°, V = 5923.9（12） A^°3, Z = 2, Dc = 3.833 mg/m^3, μ = 22.175 mm^-1, F（000） = 6116, the final R = 0.0697 and wR = 0.1959 for 10319 observed reflections with I 〉 2σ（I）. Single-crystal X-ray structure analysis reveals that 1 exhibits a one-dimensional chain structure based on sandwiched-type POM anions [Zr2（μ2-OH）2（α-SiW11O（39））2]^10- linked by Cs＋cations. In addition, catalytic tests indicate that 1 provides a sufficient driving force for the conversion from thioethers to sulfoxides/sulfones by H2O2.
基金This work was supported by the National Natural Science Foundation of China (21878006)。
文摘Different preparation routes for TiO_(2)-supported natural and synthetic clinoptilolite(TiO_(2)/CP)composites were thoroughly investigated on the basis of sol-gel,hydrothermal,and in-situ hydrothermal methods.The micro-structural features and physicochemical properties of resultant TiO_(2)/CPs were characterized via X-ray diffraction patterns,scanning(transmission)electron microscope images,Fourier transform infrared spectra,inductively coupled plasma-optical emission spectrometry methods,BET-isotherms,UV-visible spectra,and surface charge potential distributions.The results showed that in-situ hydrothermal method led to well dispersions of loaded-TiO_(2) particles on the surface of leaf-like CP,while obviously aggregated TiO_(2) on a relatively distorted structure of CP was obtained using sol-gel and hydrothermal methods.Their adsorptive and photocatalytic efficiencies for removal of crystal violet(CV)dye in aqueous solution were also explored under UV-irradiations.The results demonstrated that TiO_(2)/CPs synthesized via sol-gel and in-situ hydrothermal methods presented the excellent performances with 98% removal efficiencies as compare to the bare commercial TiO_(2) which achieved 53%removal of CV dye.While,the in-situ hydrothermally synthesized TiO_(2)/CPs were the best due to their moderate energy cost,highest adsorption capacities and removal efficiencies.Particularly,the synthetic CPs as supports exhibited synergetic photocatalytic activities for the degradation of CV dye,which is attributed to their high surface areas,better adsorption capability,and fine dispersion of TiO_(2) particles.Adsorption and degradation kinetics of CV dye were found to follow the pseudo-second and pseudo-first order models,respectively.
文摘水热体系下合成了新型层状UZM-8沸石,采用~13C交叉极化魔角旋转核磁共振(~13C CP MAS NMR)谱研究了该体系下二甲基二乙基氢氧化铵(DEDMAOH)的模板导向作用。研究结果表明,DEDMA^+与沸石发生较强的相互作用,处于沸石的不同化学环境中,起到了较强的模板导向作用。采用XRD和SEM方法对合成的UZM-8沸石进行了表征,考察了晶种和Na^+对UZM-8沸石的形成及结构的影响。实验结果表明,当n(DEDMA^+)∶n(SiO_2)<0.3时,合成体系中UZM-8沸石无法自发结晶,而当体系中存在Na^+和晶种时,n(DEDMA^+)∶n(SiO_2)=0.1时仍可合成出UZM-8沸石,且合成产物UZM-8沸石的结晶度提高,晶化时间缩短。
基金The Project was supported by the State Key Development Program for Basic Research of China(No.2009CB930400)the National Natural Science Foundation of China(Nos.21121063,51362009,51362010)
