石墨烯桥联的ZnO/Ag_(3)PO_(4)复合材料的制备及其对环丙沙星的降解性能

Preparation of graphene bridged ZnO/Ag_(3)PO_(4) composite and its degradation performance for ciprofloxacin

采用沉淀沉积法制备了石墨烯桥联的ZnO/Ag_(3)PO_(4)复合光催化材料,具有优异的可见光催化性能,通过XRD、XPS、SEM、EDS、BET、FTIR、UV-Vis DRS、PL及ESR等表征手段对其晶体结构、形貌、光学性质等进行了表征及分析,并研究了不同氧化石墨烯比例的GO-ZnO/Ag_(3)PO_(4)复合材料对模拟抗生素废水环丙沙星(CIP)的光催化降解性能。由于GO及ZnO的引入,不仅增强了GO-ZnO/Ag_(3)PO_(4)对可见光吸收,且拥有了更高的电子-空穴对的分离效率。当GO与Ag_(3)PO_(4)的质量比为1%时,GO-ZnO/Ag_(3)PO_(4)显示出最佳的光催化活性,60 min可见光照后对CIP降解率可达85.3%。捕获实验表明,超氧自由基(·O_(2)^(−))是反应过程中的主要活性物质,ZnO与Ag_(3)PO_(4)之间形成了异质结,符合Z型电子转移机制,GO的引入进一步提高了电子的快速转移,并使Z型体系更加稳定。经过6次光催化循环,降解率依然保持在70%以上,表明GOZnO/Ag_(3)PO_(4)复合材料具有优异的稳定性。

Graphene-bridged ZnO/Ag_(3)PO_(4)composite photocatalytic material,with excellent visible light catalytic performance,was prepared with the method of precipitation and deposition.Some characterization methods,includingXRD,XPS,SEM,EDS,BET,FTIR,UV-Vis DRS,PLand ESR were adopted to characterize and analyze the crystal structure,morphology,and optical properties of ZnO/Ag_(3)PO_(4)composite photocatalytic material.Meanwhile,the photocatalytic degradation performance of GO-ZnO/Ag_(3)PO_(4)with different ratios of graphene oxideto simulation antibiotics wastewater ciprofloxacin(CIP)was explored.The introduction of GO and ZnO enhances the visible light absorption of GO-ZnO/Ag_(3)PO_(4),and makes GO-ZnO/Ag_(3)PO_(4)have better separation efficiency of electron-hole pairs.When the mass fraction of GO is 1wt%,GO-ZnO/Ag_(3)PO_(4)displays the best photocatalytic activity,and the degradation rate of CIP can reach 85.3%after 60 minutes of visible light.The capture experimentprove that,in the reaction process,superoxide radical(·O_(2)^(−))is the main active substance,and a heterojunction is formed between ZnO and Ag_(3)PO_(4),which conforms to the Z-scheme electron transfer mechanism.The introduction of GO furtherly improves the rapid transfer of electrons and makes the Z-scheme system more stable.After six photocatalytic cycles,the degradation rate remained above 70%,indicating that the GO-ZnO/Ag_(3)PO_(4)composite material has excellent stability.