In situ anchor of magnetic Fe304 nanoparticles （NPs） onto the surface of natural maifanite was realized by chemical oxidation coprecipitation in hot alkaline solution. The Fe304/maifanite composites were characteriz...In situ anchor of magnetic Fe304 nanoparticles （NPs） onto the surface of natural maifanite was realized by chemical oxidation coprecipitation in hot alkaline solution. The Fe304/maifanite composites were characterized by XRD, FTIR, SEM, and TEM. These results indicated that polycrystalline Fe304 NPs with inverse spinel structure were formed and tightly dispersed on maifanite surface. Based on the measurement of surface Zeta potential of maifanite at different medium pHs, the possible combination mechanism between natural maifanite and Fe304 NPs was proposed. Then, the as- obtained composites were developed as highly efficient heterogeneous Fenton-like catalyst for the discoloration of an azo dye, Methyl Orange （MO）. The comparative tests on MO discoloration in different systems revealed that Fe304/maifanite composite exhibited much higher Fenton-like catalytic activity than Fe304 NPs and the heterogeneous Fenton- like reaction governed the discoloration of MO. Kinetic results clearly showed that MO discoloration process followed the second-order kinetic model. Fe304/maifanite compo- sites exhibited the typical ferromagnetic property detected by VSM and could be easily separated from solution by an external magnetic field.展开更多
Two important iron oxides： Fe304 and Fe203, as well as Fe304 and Fe203 nanoparticles mingling with Ag were successfully synthesized via a hydrothermal procedure. The samples were confirmed and characterized by X-ray ...Two important iron oxides： Fe304 and Fe203, as well as Fe304 and Fe203 nanoparticles mingling with Ag were successfully synthesized via a hydrothermal procedure. The samples were confirmed and characterized by X-ray diffraction （XRD）, and X-ray photoelectron spectroscopy （XPS）. The morphology of the samples was observed by transmission electron microscopy （TEM）. The results indicated Fe304, Fe203, Ag/Fe304 and Ag/Fe203 samples all were nanoparticles with smaller sizes. The samples were modified on a glassy carbon electrode and their elctrocatalytic properties for p-nitropbenol in a basic solution were investigated. The results revealed all the samples showed enhanced catalytic performances by comparison with a bare glassy carbon electrode. Furthermore, p-nitrophenol could be reduced at a lower peak potential or a higher peak current on a glassy carbon electrode modified with Ag/Fe304 or Ag/Fe203 composite nanoparticles.展开更多
基金This work was financially supported by the National Natural Science Foundation of China （Grant No. 51404083）, the Program for New Century Excellent Talents in Heilongjiang Provincial Universities （Grant No. 1253-NCET-010）, the Research Development Fund of Nianzishan Institute of Maifanite, Qiqihaer （Grant No. 201406）, and the Natural Science Foundation of Heilongjiang Province, China （Grant No. E2015065）.
文摘In situ anchor of magnetic Fe304 nanoparticles （NPs） onto the surface of natural maifanite was realized by chemical oxidation coprecipitation in hot alkaline solution. The Fe304/maifanite composites were characterized by XRD, FTIR, SEM, and TEM. These results indicated that polycrystalline Fe304 NPs with inverse spinel structure were formed and tightly dispersed on maifanite surface. Based on the measurement of surface Zeta potential of maifanite at different medium pHs, the possible combination mechanism between natural maifanite and Fe304 NPs was proposed. Then, the as- obtained composites were developed as highly efficient heterogeneous Fenton-like catalyst for the discoloration of an azo dye, Methyl Orange （MO）. The comparative tests on MO discoloration in different systems revealed that Fe304/maifanite composite exhibited much higher Fenton-like catalytic activity than Fe304 NPs and the heterogeneous Fenton- like reaction governed the discoloration of MO. Kinetic results clearly showed that MO discoloration process followed the second-order kinetic model. Fe304/maifanite compo- sites exhibited the typical ferromagnetic property detected by VSM and could be easily separated from solution by an external magnetic field.
文摘Two important iron oxides： Fe304 and Fe203, as well as Fe304 and Fe203 nanoparticles mingling with Ag were successfully synthesized via a hydrothermal procedure. The samples were confirmed and characterized by X-ray diffraction （XRD）, and X-ray photoelectron spectroscopy （XPS）. The morphology of the samples was observed by transmission electron microscopy （TEM）. The results indicated Fe304, Fe203, Ag/Fe304 and Ag/Fe203 samples all were nanoparticles with smaller sizes. The samples were modified on a glassy carbon electrode and their elctrocatalytic properties for p-nitropbenol in a basic solution were investigated. The results revealed all the samples showed enhanced catalytic performances by comparison with a bare glassy carbon electrode. Furthermore, p-nitrophenol could be reduced at a lower peak potential or a higher peak current on a glassy carbon electrode modified with Ag/Fe304 or Ag/Fe203 composite nanoparticles.
