机械力化学活化HPW-TiO_2/膨润土光催化降解甲基橙

采用溶胶-凝胶法制备了磷钨酸(HPW)改性TiO_2,并固载于膨润土上,再经机械力化学活化,得到机械力化学活化HPW-TiO_2/膨润土(MCA-HPW-TiO_2/膨润土)复合光催化剂。采用XRD,SEM,EDS技术对复合光催化剂进行了表征,并将其用于甲基橙的紫外光催化降解。表征结果显示:活性组分TiO_2和HPW成功固载于膨润土上;在机械力化学活化作用下,膨润土层间结构遭到破坏,TiO_2的XRD特征峰形呈弥散状态。实验结果表明:机械力化学活化作用对HPW-TiO_2/膨润土的光催化性能提升效果显著;在酸性及近中性条件下MCA-HPWTiO_2/膨润土均具有较高的催化活性;在溶液p H 6.2、初始甲基橙质量浓度10 mg/L、反应时间180 min、MCAHPW-TiO_2/膨润土投加量1 g/L的条件下,甲基橙去除率达88.27%;该光催化降解过程符合一级动力学模型。

Photocatalytic degradation of methyl orange with mechanochemical activated HPW-TiO2/bentonite

The phosphotungstic acid（HPW）modified TiO₂ prepared by sol-gel method was loaded onto bentonite and activated by mechanochemistry,then the mechanochemical activated HPW-TiO₂/bentonite（MCA-HPW-TiO₂/bentonite）composite photocatalyst was obtained. The photocatalyst was characterized by XRD,SEM and EDS,and was used for photocatalytic degradation of methyl orange under UV-light. The characterization results show thatThe active components of HPW and TiO₂ are effectively loaded on bentonite;Due to the mechanochemical activation,the interlayer structure of bentonite is destroyed,and the XRD characteristic peaks of TiO₂ are in the form of dispersion. The experimental results show thatThe photocatalytic capability of HPW-TiO₂/bentonite is significantly improved by mechanochemical activation;MCA-HPW-TiO₂/bentonite has high catalytic activity in wide pH range of acidity and neutrality;The removal rate of methyl orange reaches 88.27% under the conditions of solution pH 6.2,initial mass concentration of methyl orange 10 mg/L,reaction time 180 min and MCA-HPW-TiO₂/bentonite dosage 1 g/L;The photocatalytic degradation process is according with the first-order kinetics model.