Fabrication Of Silver Phosphate-based Composite Photocatalysts And Study On Its Visible-light Degradation Of Antibiotics

With the acceleration of the industrialization process,environmental issues have become serious increasingly.This paper is dedicated to solving the problem of water pollution caused by antibiotics via photocatalysis.Ag₃PO₄,an outstanding photocatalyst of?2.4 e V band gap,has many attractive advantages.In spite of the advantages,the disadvantage of its poor stability severely limits its photocatalytic activity.Therefore,the work focuses on the modification of Ag₃PO₄ to improve its stability and photocatalytic activity.The main researches are as follows:1.In this work,we successfully constructed visible-light-driven Z-scheme Sr Ti O₃/Ag/Ag₃PO₄ photocatalyst with oxygen vacancies via a hydrothermal method and followed in-situ precipitation procedure.Sr Ti O₃/Ag/Ag₃PO₄ photocatalyst exhibited highly enhanced performance for antibiotic tetracycline?TC?photodegradation compared with pure Ag₃PO₄ and Sr Ti O₃.Sr Ti O₃/Ag/Ag₃PO₄?1:3?exhibited the best photocatalytic performance under visible light illumination,the rate constant k of which was about 2.72 and 18.55 folds higher than that of Ag₃PO₄ and Sr Ti O₃,respectively.No significant deactivation of photocatalytic performance over Sr Ti O₃/Ag/Ag₃PO₄?1:3?after removal rate confirmed an enhanced stability,compared to pure Ag₃PO₄,which showed 22.1%decrease in photocatalytic activity under the same condition.Finally,the corresponding enhancement mechanism of photocatalytic degradation performance was proposed.2.The novel r GO/Ag₃PO₄/PANI ternary composites were successfully synthesized via an in-situ precipitation procedure and a following hydrothermal method,in which polyaniline?PANI?for transporting holes and reduced graphene oxide?r GO?for transferring electrons were co-incorporated with Ag₃PO₄ to reach the superior carrier separation efficiency via synergetic effect of PANI and r GO.Consequently,5%r GO/Ag₃PO₄/PANI exhibited the excellent photocatalytic performance of 86.2%removal rate towards ciprofloxacin?CIP?within 15 min,which showed excelled photocatalytic activity.After four removal rate,the composites performed better stability with 81.0%removal rate.Efficiencies of charge separation(?_sep)of r GO/Ag₃PO₄/PANI was 11.5 and 8.70 folds higher than that of Ag₃PO₄ and Ag₃PO₄/PANI,strongly manifesting synergetic effect of PANI and r GO on Ag₃PO₄ accelerated the charge separation and finally enhanced the photocatalytic activity.Finally,the corresponding enhancement mechanism of photocatalytic degradation performance was studied.