Fabrication of mesoporous CuO/ZrO 2 -MCM-41 nanocomposites for photocatalytic reduction of Cr(VI)

Abstract

h i g h l i g h t sMesoporous ZrO 2 -MCM-41synthesized by in situ incorporation process. CuO@ZM-41 synthesized by modification of CuO onto the ZrO 2 -MCM-41. CuO@ZM-41nacomposite shows semiconductor behavior and mesoporosity. High surface area, lower e À and h + recombination are enhancing the photo-reduction. g r a p h i c a l a b s t r a c tMesoporous nanocomposite (CuO@ZM-41) is synthesized by incorporating mesoporous ZrO 2 (Z) into MCM-41 (M-41) framework followed by loading of CuO by wetness impregnation method. The synergism between CuO and the support material mesoporous ZM-41 and efficient light absorption on the surface of the composite is the key factor for the reduction Cr 6+ to Cr 3+ within 30 min time. a b s t r a c tMesoporous nanocomposites of CuO/ZrO 2 -MCM-41 (CuO@ZM-41) was designed by incorporating mesoporous ZrO 2 (Z) into the high surface area MCM-41 (M-41) framework followed by loading CuO by wetness impregnation method keeping Si/Zr ratio 10. The nanocomposites were studied under PXRD, N 2 sorption, DRS spectra, FTIR, XPS, NMR, HRTEM and PL to evaluate structural, morphological, optical properties and also the mesoporosity nature of the samples. The photo-reduction of Cr 6+ was performed over CuO@ZM-41 by varying pH, substrate concentration, and irradiation time and catalyst dose. Among all the catalysts, 2 CuO@ZM-41 was found to be efficient photocatalyst for the photo-reduction of Cr 6+ . Nearly 100% reduction of Cr 6+ has been achieved by 2 CuO@ZM-41 within 30 min. Intra-particle mesoporosity, high surface area, presence of CuO nanorods and electron transfer properties are the key factors for enhancing the photo-reduction activity of 2CuO@ZM-41.

Total Oxidation of Naphthalene with Zirconia-Supported Cobalt, Copper and Nickel Catalysts

“…In this context, the broad signal in the 600-800 nm range for the CuZ 2 h UVvis diffuse reflectance spectrum (supplementary Materials) corroborates the presence of this coordination out the zirconia lattice [56].…”

“…Likewise, there are limits in the incorporation of copper in zirconia networks; so, the Cu-O species, which are not incorporated, contain Cu(II) ions with axial distortion. In this context, the broad signal in the 600-800 nm range for the CuZ 2 h UV-vis diffuse reflectance spectrum (Supplementary Materials) corroborates the presence of this coordination out the zirconia lattice [56].…”

ZnFe2O4‐Decorated Mesoporous Al2O3 Modified MCM‐41: A Solar‐Light‐Active Photocatalyst for the Effective Removal of Phenol and Cr (VI) from Water

“…In acidic medium Cr (VI) exists in HCrO 4 − form and the surface of the catalyst is highly protonated and creates a stronger electrostatic force of attraction between surface charge cations and the substrate species (HCrO 4 – ) which increase the reduction percentage (66%). At higher pH, not only the formation of negative charge on the surface but also the settlement of Cr(OH) 3 on the surface of the composite restricts the process of reduction of Cr (VI) to less toxic Cr (III) . To further confirm the active species responsible for Cr (VI) reduction, a series of scavenging test has been carried out at pH 4.…”

Electrospun Fe2O3 Entrenched SiO2 Supported N and S Dual Incorporated TiO2 Nanofibers Derived from Mixed Polymeric Template/Surfactant: Enriched Mesoporosity within Nanofibers, Effective Charge Separation, and Visible Light Photocatalysis Activity

“…(i) It possesses 3d 5 (half-filled) electronic configuration. (ii) The ionic radius of Fe 3+ (0.064 nm) is nearly similar to the ionic radius of Ti 4+ , 0.068 nm, 22 and the resulting Fe 3+ may have the ability to combine into the TiO 2 structure through a substitutional and interstitial approach.…”