Synthesis of Zr-based MOF nanocomposites for efficient visible-light photocatalytic degradation of contaminants

摘要： A novel ternary complex photocatalyst (UiO-66/g-C3N4/Ag) was fabricated by chemical protonation coating and photodeposition and its physicochemical parameters, crystal morphology, and electrochemical properties characterized using a series of techniques. Proper addition of g-C3N4 and Ag effectively enhanced the separation and mobility of photoinduced charge and improved the visible-light absorption and thereby the catalytic performance. Degradation experiments on target contaminants such as Rhodamine B (RhB) dye and 2,4-dichlorophenoxyacetic acid (2,4-d) showed that the photocatalytic ability of UiO-66/g-C3N4/Ag(15) was greatly increased compared with the parent material. Moreover, the composite could be regenerated by a simple ethanol washing process and exhibited stability and high reusability over six cycles. Finally, experiments on trapping of active species revealed that superoxide radicals (·O2?), holes (h+), and hydroxyl radicals (·OH) were primarily responsible for the photodegradation of RhB and 2,4-d.