二氧化钛/石墨氮化碳复合材料对棒曲霉素的吸附与光催化降解作用研究

Adsorption and photocatalytic degradation of patulin by titanium dioxid/graphite carbon nitride composites

中文关键词:  TiO2/g-C3N4复合材料  棒曲霉素  吸附  光降解

英文关键词:titanium dioxid/graphite carbon nitride composite material  patulin  adsorption  photocatalytic degradation

中文摘要:

      目的 探究二氧化钛/石墨氮化碳(titanium dioxid/graphite carbon nitride, TiO2/g-C3N4)复合材料对棒曲霉素(patulin, PAT)的吸附与光催化降解作用。方法 通过超声混合后再煅烧的方法制备TiO2和g-C3N4的复合材料(TiO2/g-C3N4)。分别使用傅里叶转换红外光谱分析仪(Fourier transform infrared spectrometer, FTIR)和比表面及孔径分析仪(specific surface and aperture analyzer, BET)对3种材料进行测试分析, 并研究单一材料与复合材料分别对PAT的吸附作用、复合材料在可见光下的光催化效果及暗吸附与光降解之间的协同作用。结果 TiO2/g-C3N4复合材料的FTIR图中出现了TiO2的特征峰O-H基团和Ti-O、g-C3N4的特征峰C=N和CN, 表明成功合成了TiO2/g-C3N4复合材料。结果表明TiO2和g-C3N4复合后的吸附及光催化降解效果明显优于单一材料, 且TiO2/g-C3N4复合材料暗吸附与光降解之间存在协同作用, 在温度为30℃、复合材料添加量为10 mg、吸附时间3 min、光照时间5 min时, 可完全降解初始质量浓度为0.5 μg/mL的PAT。此外, TiO2/g-C3N4对PAT的吸附存在多分子层化学吸附, 且过程符合准二级动力学模型, 对PAT的光催化降解过程符合准一级动力学模型。结论 该复合材料可快速、高效地去除PAT, 因此在果蔬及其制品、谷物和饲料中PAT的去除方面有较好的应用前景。

英文摘要:

      Objective To investigate the adsorption and photocatalytic degradation of patulin (PAT) by titanium dioxid/graphite carbon nitride (TiO2/g-C3N4) composites. Methods TiO2 and g-C3N4 composites (TiO2/g-C3N4) were prepared by ultrasonic mixing and then calcination. Fourier transform infrared spectrometer (FTIR) and specific surface and aperture analyzer (BET) were used to test and analyze three materials, and the adsorption effect of single material and composite on PAT, the photocatalytic degradation effect of composite under visible light, and the synergistic effect between dark adsorption and photocatalysis were studied. Results In the FTIR diagram of TiO2/g-C3N4 composites, the O-H group of TiO2 characteristic peaks and the C=N and CN of Ti-O and g-C3N4 characteristic peaks appear, indicating that TiO2/g-C3N4 composites were successfully synthesized. The results showed that the adsorption and photocatalytic degradation effects of TiO2 and g-C3N4 composite were significantly better than that of single material, and there was a synergistic effect between TiO2/g-C3N4 composite dark adsorption and photocatalysis. When the temperature was 30℃, the addition amount of the composite was 10 mg, the adsorption time was 3 min, and the photocatalytic degradation time was 5 min, the removal rate of PAT at the initial mass concentration of 0.5 μg/mL could reach 100%. In addition, the adsorption of PAT by TiO2/g-C3N4 had multi-molecular layer chemisorption, and the process accorded with the quasi-second-order kinetic model, and the photocatalytic degradation process of PAT accorded with the quasi-first-order kinetic model. Conclusion The composite material can remove PAT quickly and efficiently, so it has a good application prospect in the removal of PAT in fruits and vegetables and their products, grains and feeds.