Photocatalytic And Adsorption Performance Of Iron Oxide And Graphene Composites

Fe-based materials have attracted considerable attention,due to their easily obtainable,eco-friendliness,safety and good electrochemical properties.As an n-type semiconductor,?-Fe₂O₃ is the most stable phase among iron oxides and has been regarded as a promising photocatalytic material owing to its high absorbance to visible light,by controlling the reaction conditions to synthesize ?-Fe₂O₃ nanoparticles and exploring the morphology and size effect on the photoelectrochemical properties is currently one of the hot spots.Fe₃O₄ magnetic nanoparticles are used as adsorbents in the treatment of industrial wastewater in terms of toxic heavy metal ions removal.Graphene is a two-dimensional carbon material with excellent optical,thermal,electrical,and mechanical properties,and it is very popular to study the new material.Reduced graphene oxide?RGO?owning some oxygen-containing groups and sp2-hybrid domains can provide anchors for some semiconductors or precursors,as well as it can serve as a substrate fot synthesizing smaller or more dispersible nanocrystals.The ?-Fe₂O₃ composed with RGO has better photocatalytic performance due to the improvement of adsorption ability,the extended light absorption range and the lowering of electron-hole recombination.The Fe₃O₄ composed with RGO will increase its specific surface area,which is helpful to increase the adsorption sites of the adsorbent surface.1.We prepared the rod,rice-like,spindle-shaped and oblique hexagonal body in four different morphologies and sizes of ?-Fe₂O₃ particles,and explore the impact of the morphology and size of the photoelectric properties and photocatalytic activity of ?-Fe₂O₃ particles.The result shows that: the nano-sized ?-Fe₂O₃ particles have better photocatalytic performance than the micron-sized particles.Different morphologies of ?-Fe₂O₃ have different internal lattice structures,which leads to their different electron transport rates and photocatalytic performance.2.The ?-Fe₂O₃/RGO composite were synthesized by a facile one-step hydrothermal method with an aim to improve the photocatalytic efficiency of the ?-Fe₂O₃.The ?-Fe₂O₃/RGO composite exhibits 100% of MO degradation under the irradiation of Xenon lamp for 100 minutes,which is almost twice of the neat sample.The enhanced performance of the composite materia was ascribed to strong interaction and development of a synergestic effect between the ?-Fe₂O₃ and RGO,which can be described by the following three aspects: the improvement of adsorption ability,extended light absorption range and the lowering of electron-hole recombination.3.The prepared Fe₃O₄ and Fe₃O₄/RGO composites were modified by CTAB.We studied the impact of time,temperature,PH and content of graphene on the adsorption performance.The adsorption reaction is exothermic,the better the adsorption the lower temperature.Adsorption reaction rate is very fast,it can be achieved adsorption saturation within 30 min.When the PH value is near 3.5,with mass ratio of Fe₃O₄ and RGO at 2: 1,the adsorption capacity is about 251 mg per gram at room temperature.