Visible-Light-Driven Photocatalytic Degradation of Rhodamine B over Bimetallic Cu/Ti-MOFs

Abstract

The first copper-doped titanium-based amine-dicarboxylate metal-organic framework was synthesized by the solvothermal approach in this article, with a Cu2+/Ti4+ ratio of 0.15 (15% Cu/Ti-MOFs). X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectra, N2 adsorption-desorption studies, and UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) were all used to identify the crystalline and properties of the semiconductors. The rate constants of 15% Cu/Ti-MOFs to degrade Rhodamine B (RhB) were roughly two times higher than NH2-Ti-MOFs. Furthermore, 15% Cu/Ti-MOFs photocatalysts remained stable after three cycles. The trapping test revealed that the principal active species in the degradation performance were hydroxyl radicals and holes.

Enhanced Heterogeneous Catalytic Activity of Peroxymonosulfate for Rhodamine B Degradation via a CoII-Based Metal–Organic Framework

“…Co 2+ is the most efficient transition-metal ion for PMS activation, but the nonrecyclable nature of Co 2+ during degradation cycles poses significant secondary environmental risks, restricting the widespread usage of homogeneous Co 2+ /PMS systems. − Also, photocatalytic chemical oxidation using potent oxidants can be used to degrade organic pollutants. In fact, transition-metal species in metal–organic frameworks (MOFs) have the same function as substitute catalysts to activate oxidants and produce free radicals. − As catalysts for oxidation processes, only a small number of MOFs have been investigated, − and they are less used as catalysts to activate PMS. The activation of PMS is one of the most important processes to generate sulfate (SO 4 •– ), which has a high standard redox potential (2.5–3.1 V).…”

A State-of-the-Art of Metal-Organic Frameworks for Chromium Photoreduction vs. Photocatalytic Water Remediation

“…Overall, the current state-of-the-art challenges of photocatalysts for water remediation purposes are (i) widening the band gap to make the semiconductors functional under visible-light illumination, (ii) circumventing the carrier recombination while boosting their separation, and (iii) increase their mobility through the photocatalyst’s crystalline framework [ 41 , 42 ]. In this respect, doping and heterojunction engineering have gained strong attention during recent years in order to improve the carrier’s mobility [ 43 , 44 , 45 ]. Another important aspect is to endow the material with specific surface chemistry able to retain the photo-transformed intermediate and final species [ 46 ].…”