Co, Cu, Fe, and Ni Deposited over TiO2 and Their Photocatalytic Activity in the Degradation of 2,4-Dichlorophenol and 2,4-Dichlorophenoxyacetic Acid

Abstract

Pure TiO2 synthesized by the sol-gel method and subsequently deposited at 5% by weight with Co, Cu, Fe, and Ni ions by the deposition–precipitation method were studied as photocatalysts. The nanomaterials were analyzed by SEM, TEM, UV-Vis DRS, DRX, Physisorption N2, and XPS. The SEM and TEM images present a semi-spherical shape with small agglomerations of particles and average size between 63 and 65 nm. UV-Vis results show that a reduction below 3.2 eV exhibits a redshift displacement and increment in the optical absorption of the nanoparticles promoting the absorption in the UV-visible region. XRD spectra and analysis SAED suggest the characteristic anatase phase in TiO2 and deposited materials according to JCPDS 21-1272. The specific surface area was calculated and the nanomaterial Ni/TiO2 (21.3 m2 g−1) presents a slight increment when comparing to TiO2 (20.37 m2g−1). The information generated by the XPS spectra present the deposition of metallic ions on the support and the presence of different valence states for each photocatalyst. The photocatalytic activity was carried out in an aqueous solution with 80 mg L−1 of 2,4-D or 2,4-DCP under UV light (285 nm) with 100 mg L−1 of each photocatalysts for 360 min. The nanomaterial that presented the best efficiency was Ni/TiO2, obtaining a degradation of 85.6% and 90.3% for 2,4-D and 2,4-DCP, respectively. Similarly, this material was the one that presented the highest mineralization, 68.3% and 86.5% for 2,4-D and 2,4-DCP, respectively. Photocatalytic reactions correspond to the pseudo-first-order Langmuir–Hinshelwood model.

Investigating and studying the effects of coating converter colors with the approach of converting solar energy into electric current in solar cells on porous silica

“…The prominent peaks were compared with JCPDS data (JCPDS 21-1272) and the peaks obtained in the pattern coincides well with the literature. The intensity of the peak is high and the width of (101) plane at 2=25.313 becomes narrow [11,12]. The sharpness of the peak uncovers that the samples possess a good crystalline nature.…”

Nanocomposites for Photocatalysis

“…This study investigates the photocatalytic properties of pure TiO 2 nanoparticles synthesized via the sol-gel method and subsequently modified with 5% by weight of Co, Cu, Fe, and Ni ions through the deposition-precipitation method. The nanomaterials underwent thorough characterization using various techniques, including SEM, TEM, UV-Vis DRS, X-ray diffraction (XRD), nitrogen physisorption, and X-ray photoelectron spectroscopy (XPS) [15].…”

Visible Light Photocatalytic Degradation of Methylene Blue Dye and Pharmaceutical Wastes over Ternary NiO/Ag/TiO2 Heterojunction

“…To improve the photocatalytic activity, shift the absorption in the visible light of the solar spectrum, and slow down the recombination of photoexcited electron–hole in TiO 2 , various strategies have been employed to change the electronic structure of TiO 2 , including doping, creating oxygen vacancies, or creating a junction with other photocatalytically active metal-oxide nanomaterials . Doping TiO 2 with transition metals such as Ag, Ni, Cu, and Pd nanoparticles enhances the photocatalytic performance of TiO 2 . More precisely, Ag and Au have been widely utilized due to their ability to form Schottky heterostructures with TiO 2 .…”

“… 18 Doping TiO 2 with transition metals such as Ag, Ni, Cu, and Pd nanoparticles enhances the photocatalytic performance of TiO 2 . 19 More precisely, Ag and Au have been widely utilized due to their ability to form Schottky heterostructures with TiO 2 . However, Ag nanoparticles are preferable due to the higher work function and lower cost than Au nanoparticles.…”