Catalytic Decolorization of Rhodamine B, Congo Red, and Crystal Violet Dyes, with a Novel Niobium Oxide Anchored Molybdenum (Nb–O–Mo)

Abstract

In this work, a new metal-to-metal charge transfer (MMCT) heterogeneous catalyst (Nb–O–Mo) was synthesized by a chemical grafting method under an inert atmosphere. The activity of the covalently anchored oxo-bridged Nb–O–Mo catalyst was estimated for decolorization of Rh B, congo red, and crystal violet dyes in an aqueous solution under fluorescent light. The catalyst was characterized via X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray spectrometer, Fourier-transform infrared, and FT-Raman. The catalytic decolorization was evaluated from the UV spectra of dyes in aqueous solution by changing different factors, including dye concentration, temperature, and catalyst loading. Decolorization percentages were 83%–89%, 86%–95%, 97%–99% for Rh B, Congo Red and Crystal Violet in 1 min at 298 K, showing the best performance among other catalysts. Decolorization efficiency for 50 ppm of Rh B was improved from 92% to 98%, with a temperature increase to 318 K.

In Situ Kinetic Observations on Crystal Nucleation and Growth

“…42,149,196−198 Compared to TEM, STEM, SEM, and AFM, OM shows the lowest spatial resolution. Based on the Rayleigh's criterion, the spatial resolution in any type of (far field) OM is restricted by the diffraction limit, which is related to the wavelength of the imaging light 199,200 x n 0.61 sin = (14) where Δx, λ, n, θ, and the term n sin θ represent the distance separating two particles, the wavelength of the imaging light, the refractive index, the acceptance angle of the objective, and the objective's numerical aperture, respectively. It is important to note that eq 14 describes only the principal limitations of lateral spatial resolution in OM.…”

“…Crystallization is one of the most secretive, but pervasive, important phenomena in nature. − The mystery of crystallization lies in how crystals with long-range ordered structures originate from the fundamental building blocks like ions, atoms, or molecules, which only interact with their neighbors. , It involves a complex thermodynamic and kinetic process which is difficult to detect experimentally . Its pervasiveness and importance lie in that it takes place in many natural processes, such as the formation of minerals and ice, the amyloid aggregation leading to Alzheimer’s desease, etc. − Moreover, most of the artificial products like dyes, ceramics, optical crystals, and medicines are in their crystalline solid states. − Hence, understanding the crystallization process at the nanoscale or even at the atomic scale is an important subject with intense practical interest. − …”

Ce‐Doped MoO3 Photocatalyst as an Environmental Purifier for Removal of Noxious Rhodamine B Organic Pollutant in Wastewater

“…As a tracer, rhodamine B has been used in the food and textile sectors. [26][27][28] The health of humans and animals is both negatively affected at the same time. It is necessary for all researchers to remove the noxious dyes using different types strategies and photocatalysts.…”

Ag3PO4-Deposited TiO2@Ti3C2 Petals for Highly Efficient Photodecomposition of Various Organic Dyes under Solar Light

“…Organic dyes at high concentrations (5–1500 mg/L) cause significant environmental and organismal toxicity, including carcinogenic, mutagenic, and teratogenic effects [ 6 , 7 , 8 ]. Owing to their low removal capacity, conventional biological processes used to remove dyes, such as flocculation, filtration, precipitation, and coagulation, have gradually become obsolete [ 9 , 10 ].…”