光触媒活化过氧单硫酸盐(PMS)降解污染物已广泛应用于可见光下的废水处理。聚对苯二甲酸乙二醇酯(PET)广泛应用于日常生活中,但是废塑料对环境有不可逆转的负面影响。在本文中,合成了ZIF-67/g-C3N4S-方案异质结催化剂作为光催化剂,以与PMS配合对PET降解具有良好的效果。结果表明,在催化剂的综合作用下,PET的降解率可达60.63±2.12%,PMS,和光。在这个实验中,催化剂与塑料比的影响,PMS浓度,水性pH值,和无机阴离子对塑料降解的光催化协同PMS体系进行了讨论,并通过对比试验强调了该系统降解PET的优异性能。电子自旋共振(ESR)和自由基猝灭实验表明,SO4•-对PET降解性能的贡献最大。此外,气相色谱和液相色谱-质谱(LC-MS)分析结果表明,塑料降解产物中含有CO,CH4和有机小分子液体燃料。最后,提出了光/PMS体系降解水中PET的可能机理。本文为处理水中废弃微塑料提供了可行的解决方案。
Photocatalyst-activated peroxymonosulfate (PMS) degradation of pollutants is already widely used for wastewater treatment under visible light. Polyethylene terephthalate (PET) is widely used in daily life, but waste plastics have an irreversible negative impact on the environment. In this paper, the ZIF-67/g-C3N4 S-scheme heterojunction catalyst was synthesized as a photocatalyst to achieve a good effect on PET degradation in coordination with PMS. The results indicated that PET could be degraded up to 60.63 ± 2.12 % under the combined effect of catalyst, PMS, and light. In this experiment, the influence of catalyst-to-plastic ratio, PMS concentration, aqueous pH, and inorganic anions on plastic degradation by the photocatalytic synergistic PMS system was discussed, and the excellent performance of this system for degrading PET was highlighted through a comparative test. Electron spin resonance (ESR) and free radical quenching experiments demonstrated that SO4•- contributes the largest amount to the PET degradation performance. Furthermore, results from gas chromatography and liquid chromatography-mass spectrometry (LC-MS) indicated that the plastic degradation products include CO, CH4, and organic small-molecule liquid fuels. Finally, a possible mechanism for the light/PMS system to degrade PET in water was suggested. This paper provides a feasible solution to treat waste microplastics in water.