One step integration of plasmonic Ag2CrO4/Ag/AgCl into HKUST-1-MOF as novel visible-light driven photocatalyst for highly efficient degradation of mixture dyes pollutants: Its photocatalytic mechanism and modeling

Ag2CrO4-AgCl/Ag nanoparticles and metal-organic framework (HKUST-1) were effectively coupled via an in situ hydrothermal growth strategy to form a plasmonic Z-scheme photocatalyst for the photocatalytic degradation of binary mixture of amido-black (AB) and orange G (OG) dyes under UV-Vis light irradiation. This was done to take advantage of the high AB and OG adsorption capacity of the HKUST-1 MOF and the photocatalytic properties of pre-formed Ag2CrO4/AgCl/Ag nanoparticles in a single material. The Ag2CrO4-Ag-AgCl-HKUST-1 plasmonic Z-Scheme photocatalyst was characterized by XRD, SEM, FESEM, EDS and PL, UV-Vis diffuse reflectance spectroscopy. On the basis of photocatalytic activity and band structure analysis, two-step plasmonic Z-scheme electron transfer and one-step direct interspecies electron transfer were proposed for this composite. The Z-scheme electron transfer was caused due to the localized surface plasmon resonance of metallic Ag nanoparticles as well as the band gap photoexcitation of Ag2CrO4/AgCl and direct interspecies electron transporters can be attributed to the presence of HKUST-1 MOF, which not only acted as hole transporters for suppressing the photogenerated carrier recombination, but also played as a sensitizer for enhancing visible light absorption. (C) 2019 Published by Elsevier Ltd.