废旧MoSi_(2)回收产物烧结制备Fe_(2)(MoO_(4))_(3)的组织形貌和性能

Microstructure and properties of Fe_(2)(MoO_(4))_(3) prepared by sintering recovery products from waste MoSi_(2)

采用热蒸发法回收废旧MoSi_(2)氧化煅烧产物MoO_(3),以回收MoO_(3)粉末与Fe_(2)O_(3)为原料,经反应烧结制备Fe_(2)(MoO_(4))_(3)。讨论了MoSi_(2)完全氧化所需的时间和温度,并研究了Fe_(2)(MoO_(4))_(3)材料的组织形貌、线收缩率、体积密度和光谱学性能。结果表明:废旧MoSi_(2)材料粉末经500℃煅烧120 min以上时间即可完全氧化。在MoO_(3)与Fe_(2)O_(3)反应烧结过程中,烧结温度越高,MoO_(3)与Fe_(2)O_(3)反应越完全,所制备的Fe_(2)(MoO_(4))_(3)材料空隙随之增多,线收缩率升高,体积密度降低。与纯Fe_(2)(MoO_(4))_(3)材料相比,Fe_(2)(MoO_(4))_(3)和MoO_(3)复合相的光生电子–空穴对更不易复合,理论光催化活性更高。以亚甲基蓝为染料,纯Fe_(2)(MoO_(4))_(3)对其具有良好的吸附性能,而Fe_(2)(MoO_(4))_(3)和MoO_(3)复合相则表现出优异的光催化性能,且Fe_(2)(MoO_(4))_(3)和MoO_(3)复合相的光催化降解循环稳定性最好。

MoO_(3) was recovered from waste MoSi_(2) after oxidation roasting by thermal evaporation method,and Fe_(2)(MoO_(4))_(3) was prepared by reaction sintering method using the recovered MoO_(3) and Fe_(2)O_(3) as raw materials.The time and temperature for the complete oxidation of MoSi_(2) were discussed,and the microstructure,linear shrinkage,volume density,spectral properties of the prepared Fe_(2)(MoO_(4))_(3) materials were studied.The results show that,the waste MoSi_(2) powders can be completely oxidized after calcination at 500℃for more than 120 min.During the reaction sintering process of MoO_(3) and Fe_(2)O_(3),the higher the sintering temperature,the more complete the reaction between MoO_(3) and Fe_(2)O_(3);the void of the prepared Fe_(2)(MoO_(4))_(3) materials increases,the line shrinkage rate increases,and the volume density decreases.Fluorescence spectrum analysis shows that,the photogenerated electron-hole pairs of the Fe_(2)(MoO_(4))_(3) and MoO_(3) composite materials are more difficult to be recombined than those of the pure Fe_(2)(MoO_(4))_(3),showing the higher photocatalytic activity for the composites.Using methylene blue as dye,the pure Fe_(2)(MoO_(4))_(3) has the good adsorption performance,while the Fe_(2)(MoO_(4))_(3) and MoO_(3) composites show the excellent photocatalytic performance,and the mixture of Fe_(2)(MoO_(4))_(3) and MoO_(3) composites has the best photocatalytic degradation cycle stability.