Band Gap Energies and Photocatalytic Properties of CdS and Ag/CdS Nanoparticles for Azo Dye Degradation

Abstract

CdS nanoparticles were synthesized by the ultrasonic-assisted sol-gel method and characterized by X-ray diffraction (XRD). The Ag-doped CdS (Ag/CdS) nanoparticles were also synthesized by the ultrasonic-assisted sol-gel method and characterized by XRD, X-ray fluorescence spectrometry, scanning electron microscopy, and energy-dispersive X-ray analysis. The calculated sizes and experimental results are in good agreement. The calculated band-gaps of CdS and Ag/CdS were found to be 2.62 and 2.46 eV, respectively. Photocatalytic degradation of Direct Red 264 azo dye was investigated with CdS and Ag/CdS under UV-C and visible light irradiation. Experimental results indicate that the degradation rate of DR 264 follows pseudo second-order kinetics. Also, the intraparticle diffusion coefficients of CdS and Ag/CdS were determined.

Structural, Optical, and Isothermic Studies of CuFe2O4 and Zn‐Doped CuFe2O4 Nanoferrite as a Magnetic Catalyst for Photocatalytic Degradation of Direct Red 264 Under Visible Light Irradiation

“…Fard et al . studied CdS and Ag/CdS nanoparticles on photocatalytic degradation of Direct Red 264 and its isothermic and kinetic data .…”

Elimination of direct red 264 using magnetic pure and Zn‐doped NiFe2O4 nanophotocatalysts under visible light irradiation: Isothermic and kinetic studies

“…At given time, sampling was performed and the external magnetic field did the removal of catalyst. The concentration of dye in the solution was determined by UV–Vis spectrophotometer at the maximum absorption wavelength of DR 264 (501 nm) .…”

“…About 0.2 g catalyst and 10 mL H 2 O 2 (0.1 M) were dissolved in aqueous solution of DR 264 (80, 100, 120, 140, and 160 ppm) into a quartz cell then irradiated by visible light. Sampling was carried out at various time and kinetic studies were performed …”

“…Visible light irradiation was (400 W xenon lamp) applied under continuous stirring. Sampling was performed after 2 h and the final concentration was calculated .…”

Preparation of CoFe2O4/sawdust and NiFe2O4/sawdust magnetic nanocomposites for removal of oil from the water surface

“…In this method, the pseudo‐first‐order and pseudo‐second‐order kinetic equations for the investigation of the kinetics of oil absorption by the absorbents were used. From the kinetic equations, we can determine the equilibrium and kinetic constants . The first‐order kinetic equation (Logergern) is as follows: where q e and q t are the amounts of the absorbed material per unit mass of the absorbent in equilibrium and at time t , respectively, and k 1 is the rate constant of pseudo‐first‐order absorption.…”