The visible light driven copper based metal-organic-framework heterojunction:HKUST-1@Ag-Ag3PO4 for plasmon enhanced visible light photocatalysis

In this work, HKUST-1, a copper based Metal-organic framework (MOF) was incorporated with silver phosphate (Ag3PO4)and Ag nanoparticles (Ag NPs) to develop a novel three component visible light active Ag/Ag3PO4/HKUST-1 photocatalyst. The HKUST-1 was synthesized via facile microwave assisted route followed by deposition of Ag3PO4 on the HKUST-1 by simple solution phase reaction. The materials were characterized by XRD, FT-IR, FESEM, HRTEM, UV-vis DRS, BET and PL analysis. The photocatalytic activity of as prepared systems was investigated systematically by degrading an organic azo dye, Ponceau BS (PBS) under visible-light irradiation. Among the as synthesized systems, the ternary Ag/Ag3PO4/HKUST-1 heterostructured system exhibited highest photocatalytic activity and improved stability compared to others for the degradation of PBS under visible light. The superior activity and improved stability of this ternary heterostructured photocatalyst was attributed to the synergistic effects from surface plasmon resonance (SPR) of Ag NPs and sequential energy transfer via Z-scheme mechanism, for effective separation of electron-hole pairs. Radical-trapping experiments demonstrate that holes (h(+)) and O--(center dot)2 are primary reactive species involved in photocatalytic oxidation process. Moreover, the three component Ag/Ag3PO4/HKUST-1 photocatalyst did not show any obvious loss of photocatalytic activity during five cycle tests, which indicate that the heterostructured photocatalyst is highly stable and can be used repeatedly. Therefore, the work provides new insights into the design and fabrication of Metal-organic frameworks (MOFs) for use as a visible light photocatalyst for degrading organic contaminants. (C) 2017 Elsevier B.V. All rights reserved.