Preparation of core-shell Ag_3PO_4@GOQDs and degradation of ciprofloxacin under visible light

摘要

To solve the problem of photocorrosion of Ag3PO4, a chemical deposition method was used to prepare a visiblelight-active core-shell composite (Ag3PO4@GOQDs) photocatalyst containing silver phosphate (Ag3PO4), graphene oxide (GO), and graphene oxide quantum dots (GOQDs). The degradation efficiency of 2.5 wt% Ag3PO4@GOQDs for ciprofloxacin was 98.7% within 18 min through the synergistic effect of adsorption and photocatalysis. Even after 6 repeated cycles, Ag3PO4@GOQDs exhibited excellent stability. GOQDs improved the adsorption performance and promoted the transmission of photogenerated electrons, whereas the coating of Ag3PO4 slowed down the photocorrosion and enhanced the stability and photocatalytic activity of the interface. Free radical capture experiments confirmed that h(+) and center dot O2- were the main active species during the photocatalytic degradation of ciprofloxacin.