Morphology Controlled Synthesis And Photocatalytic Properties Of Fe Based Semiconductor Nanomaterials

In this paper,FeWO4 nanomaterials were prepared by hydrothermal method,and the effects of thermal stability and calcining on their photocatalytic capacity were studied by calcining.At the same time,Bi7.89W0.11O12.16 nanomaterials were synthesized by hydrothermal method,and the thermal stability and photocatalytic properties of the nanomaterials were also studied.The main contents of this paper are as follows:(1)With ferrous sulfate as a source of iron,sodium tungstate as the tungsten source,under the condition of pH=8,using Na2[EDTA]as template,using CTAB as surfactant(reaction temperature= 180℃,reaction time=12h,filling ratio=60%),FeWO4 nanomaterials were synthesized via hydrothermal method.The phase of the products was determined by XRD,and the morphology of the products was observed by SEM and TEM.The FeWO4 nanomaterials with size between 50nm and 200nm were finally synthesized.(2)The adsorption and photocatalytic properties of FeWO4 synthesized in(1)were studied through degrading RhB solution.The adsorption and photocatalytic properties of FeWO4 were significantly improved by annealing at 310℃.The thermal stability was studied by TG and the samples before and after annealed were tested by XRD,SEM,BET,IR.It is found that the phase of the samples before and after annealed is unchanged,and the crystallinity of the samples is improved.There is no obvious change in morphology and a slightly larger grain size,resulting in a slight decrease in specific surface area and the organic groups on the surface of the samples disappeared.(3)Bi7.89W0.11O12.16 nanomaterials were synthesized by hydrothermal method using peroxy tungstic acid generated from tungsten powder and hydrogen peroxide as tungsten source and bismuth nitrate as Bi source,the pH was adjusted to 2.0.By XRD,the synthesized Bi7.89W0.11O12.16 is pure phase,belonging to the crystal of tetragonal crystal,and its crystallinity is good.The micromorphology of the products was observed by SEM,and the products were mainly in the form of flaky agglomerates.The TG shows that the thermal stability is good.The band gap of the product is 2.35eV.The photocatalytic property of Bi7.89W0.11O12.16 was studied with RhB solution as a degrading dye.Under the irradiation of 500W Xe light source,the RhB solution(1 x 10-5mol/L)can be degraded completely within 20 min.