TiO_(2)/蒙脱土复合材料光催化降解丁基黄药性能研究

Study on Photocatalytic Degradation Properties of Butyl Xanthate by TiO_(2)/Montmorillonite Composites

浮选废液中残余的黄药会严重危害自然生态及环境,为实现对黄药的高效降解,依据固相扩散原理,采用固相研磨—粉末烧结法成功制备出了TiO_(2)/蒙脱土(MMT)复合材料,通过XRD、FTIR、SEM、紫外-可见光吸收光谱和光致发光光谱等检测手段对材料的结构、形貌和光化学特性进行表征,并在紫外光条件下考察了TiO_(2)负载量、光催化剂用量、丁基黄药初始浓度和黄药种类等因素对其光催化降解性能的影响,根据活性基猝灭试验和模拟废液的实时吸光光谱结果探讨了对丁基黄药的光催化降解机理。结果表明,80%TiO_(2)/MMT具有更高的紫外光吸收性能和较低的光生载流子复合效率,0.2 g/L的光催化剂在光照30 min后对初始浓度为20 mg/L丁基黄药的光催化降解率达到99.52%,且催化剂的重复利用性高,可以有效降解多种黄药。超氧自由基(·O_(2)^(-))和空穴(h^(+))是光催化降解丁基黄药的主要活性物质,且光催化降解过程中产生了过黄药这一中间产物。

The residual xanthate in flotation wastewater will seriously endanger the natural ecology and environment.In order to degrade xanthate efficiently,TiO_(2)/montmorillonite(MMT)composite materials were prepared by grinding and sintering method based on the principle of solid diffusion.XRD,FTIR,SEM,UV-Vis spectroscopy and PL spectroscopy were used to characterize the structure,morphology and photochemical properties of the obtained composites.The effects of TiO_(2) loading amount,catalyst dosage,initial concentration of butyl xanthate and xanthate type on its photocatalytic degradation performance were investigated under UV irradiation.The photocatalytic degradation mechanism of butyl xanthate was proposed through the active group scavenging experiment and real-time absorbance curves of simulated wastewater.The results showed that 80%TiO_(2)/MMT had higher ultraviolet absorption performance and lower recombination rate of photogenerated carriers.Under the conditions of 0.2 g/L catalyst dosage and 20 mg/L initial concentration of butyl xanthate,the photocatalytic degradation rate of butyl xanthate reached as high as 99.52%after 30 minutes of irradiation.The composite materials showed excellent reusability and could degrade multiple xanthates.·O_(2)^(-)and h+were the main active substances for photocatalytic degradation of butyl xanthate,and peroxy xanthate was produced as intermediate product in the photocatalytic process.