Green and recyclable solid acid catalysts are in urgent demand as a substitute for conventional liquid mineral acids.In this work,a series of novel sulfonic acid-functionalized core-shell Fe_(3)O_(4)@carbon microspher...Green and recyclable solid acid catalysts are in urgent demand as a substitute for conventional liquid mineral acids.In this work,a series of novel sulfonic acid-functionalized core-shell Fe_(3)O_(4)@carbon microspheres(Fe_(3)O_(4)@C-SO_(3)H)have been designed and synthesized as an efficient and recyclable heterogeneous acid catalyst.For the synthesis,core-shell Fe_(3)O_(4)@RF(resorcinol-formaldehyde)microspheres with tunable shell thickness were achieved by interfacial polymerization on magnetic Fe_(3)O_(4)microspheres.After high-temperature carbonization,the microspheres were eventually treated by surface sulfonation,re sulting in Fe_(3)O_(4)@C-x-SO_(3)H(x stands for carbonization temperature)microspheres with abundant surface SO_(3)H groups.The obtained microspheres possess uniform core-shell structure,partially-graphitized carbon skeletons,superparamagnetic property,high magnetization saturation value of 10.6 emu/g,and rich SO_(3)H groups.The surface acid amounts can be adju sted in the range of 0.59-1.04 mmol/g via sulfonation treatment of carbon shells with different graphitization degrees.The magnetic Fe_(3)O_(4)@C-x-SO_(3)H microspheres were utilized as a solid acid catalyst for the acetalization reaction between benzaldehyde and ethylene glycol,demonstrating high selectivity(97%)to benzaldehyde ethylene glycol acetal.More importantly,by applying an external magnetic field,the catalysts can be easily separated from the heterogeneous reaction solutions,which later show well preserved catalytic activity even after 9 cycles,revealing good recyclability and high stability.展开更多
Environment-friendly nano-catalysts capable of activating peroxymonosulfate(PMS)have received increasing attention recently.Nevertheless,traditional nano-catalysts are generally well dispersed and difficult to be sepa...Environment-friendly nano-catalysts capable of activating peroxymonosulfate(PMS)have received increasing attention recently.Nevertheless,traditional nano-catalysts are generally well dispersed and difficult to be separated from reaction system,so it is particularly important to develop nano-catalysts with both good catalytic activity and excellent recycling efficiency.In this work,magnetically recoverable Fe_(3)O_(4)-modified ternary CoFeCu-layered double hydroxides(Fe_(3)O_(4)/CoFeCu-LDHs)was prepared by a simple co-precipitation method and initially applied to activate PMS for the degradation of Rhodamine B(Rh B).X-ray diffraction(XRD),fourier transform infrared spectrometer(FT-IR),scanning electron microscope(SEM),transmission electron microscopy(TEM),Brunauer-Emmett-Teller method(BET),and vibrating sample magnetometer(VSM)were applied to characterize morphology,structure,specific surface area and magnetism.In addition,the effects of several key parameters were evaluated.The Fe_(3)O_(4)/CoFeCu-LDHs exhibited high catalytic activity,and Rh B degradation efficiency could reach 100%within 20 min by adding 0.2 g/L of catalyst and 1 mmol/L of PMS into 50 mg/L of Rh B solution under a wide pH condition(3.0-7.0).Notably,the Fe_(3)O_(4)/CoFeCu-LDHs showed good super-paramagnetism and excellent stability,which could be effectively and quickly recovered under magnetic condition,and the degradation efficiency after ten cycles could still maintain 98.95%.Both radicals quenching tests and electron spin resonance(ESR)identified both HO·and SO_(4)^(·-) were involved and SO_(4)^(·-) played a dominant role on the RhB degradation.Finally,the chemical states of the sample’s surface elements were measured by X-ray photoelectron spectroscopy(XPS),and the possible activation mechanism in Fe_(3)O_(4)/CoFeCu-LDHs/PMS system was proposed according to comprehensive analysis.展开更多
基金the Scientific and Technological Innovation Team Project of the Shaanxi Innovation Capability Support Plan,China(2022TD-30)the Youth Innovation Team of Shaanxi Universities(2019-2022)+2 种基金the Top Young Talents Project of“Special support program for high-level talents”in the Shaanxi Province(2018-2023)the International Science and Technology Cooperation Program of the Shaanxi Province(2022KW-39)Xi’an Science and Technology Planning Project(2022JH-RYFW-0196).
基金financially supported by the National Natural Science Foundation of China(Nos.21875044,52073064,22005058 and 22005057)National Key R&D Program of China(No.2020YFB2008600)+3 种基金Key Basic Research Program of Science and Technology Commission of Shanghai Municipality(No.20JC1415300)Program of Shanghai Academic Research Leader(No.19XD1420300)China Post-doctoral Science Foundation(Nos.2020M670973,BX20200085)the State Key Laboratory of Transducer Technology of China(No.SKT1904)。
文摘Green and recyclable solid acid catalysts are in urgent demand as a substitute for conventional liquid mineral acids.In this work,a series of novel sulfonic acid-functionalized core-shell Fe_(3)O_(4)@carbon microspheres(Fe_(3)O_(4)@C-SO_(3)H)have been designed and synthesized as an efficient and recyclable heterogeneous acid catalyst.For the synthesis,core-shell Fe_(3)O_(4)@RF(resorcinol-formaldehyde)microspheres with tunable shell thickness were achieved by interfacial polymerization on magnetic Fe_(3)O_(4)microspheres.After high-temperature carbonization,the microspheres were eventually treated by surface sulfonation,re sulting in Fe_(3)O_(4)@C-x-SO_(3)H(x stands for carbonization temperature)microspheres with abundant surface SO_(3)H groups.The obtained microspheres possess uniform core-shell structure,partially-graphitized carbon skeletons,superparamagnetic property,high magnetization saturation value of 10.6 emu/g,and rich SO_(3)H groups.The surface acid amounts can be adju sted in the range of 0.59-1.04 mmol/g via sulfonation treatment of carbon shells with different graphitization degrees.The magnetic Fe_(3)O_(4)@C-x-SO_(3)H microspheres were utilized as a solid acid catalyst for the acetalization reaction between benzaldehyde and ethylene glycol,demonstrating high selectivity(97%)to benzaldehyde ethylene glycol acetal.More importantly,by applying an external magnetic field,the catalysts can be easily separated from the heterogeneous reaction solutions,which later show well preserved catalytic activity even after 9 cycles,revealing good recyclability and high stability.
基金supported by the Key Research and Development(R&D)Projects of Shanxi Province(No.201803D31050)。
文摘Environment-friendly nano-catalysts capable of activating peroxymonosulfate(PMS)have received increasing attention recently.Nevertheless,traditional nano-catalysts are generally well dispersed and difficult to be separated from reaction system,so it is particularly important to develop nano-catalysts with both good catalytic activity and excellent recycling efficiency.In this work,magnetically recoverable Fe_(3)O_(4)-modified ternary CoFeCu-layered double hydroxides(Fe_(3)O_(4)/CoFeCu-LDHs)was prepared by a simple co-precipitation method and initially applied to activate PMS for the degradation of Rhodamine B(Rh B).X-ray diffraction(XRD),fourier transform infrared spectrometer(FT-IR),scanning electron microscope(SEM),transmission electron microscopy(TEM),Brunauer-Emmett-Teller method(BET),and vibrating sample magnetometer(VSM)were applied to characterize morphology,structure,specific surface area and magnetism.In addition,the effects of several key parameters were evaluated.The Fe_(3)O_(4)/CoFeCu-LDHs exhibited high catalytic activity,and Rh B degradation efficiency could reach 100%within 20 min by adding 0.2 g/L of catalyst and 1 mmol/L of PMS into 50 mg/L of Rh B solution under a wide pH condition(3.0-7.0).Notably,the Fe_(3)O_(4)/CoFeCu-LDHs showed good super-paramagnetism and excellent stability,which could be effectively and quickly recovered under magnetic condition,and the degradation efficiency after ten cycles could still maintain 98.95%.Both radicals quenching tests and electron spin resonance(ESR)identified both HO·and SO_(4)^(·-) were involved and SO_(4)^(·-) played a dominant role on the RhB degradation.Finally,the chemical states of the sample’s surface elements were measured by X-ray photoelectron spectroscopy(XPS),and the possible activation mechanism in Fe_(3)O_(4)/CoFeCu-LDHs/PMS system was proposed according to comprehensive analysis.
