Biosynthesis, characterization and catalytic activity of an Ag/zeolite nanocomposite for base- and ligand-free oxidative hydroxylation of phenylboronic acid and reduction of a variety of dyes at room temperature

Abstract

A green synthesis of an Ag/zeolite nanocomposite and its catalytic activity were investigated. Its catalytic efficiency remains unaltered even after several repeated cycles.

Biosynthesis of Ag/almond shell nanocomposite as a cost-effective and efficient catalyst for degradation of 4-nitrophenol and organic dyes

“…8,[19][20][21] However, the green synthesis of the Ag/almond shell nanocomposite, in which Ruta graveolens leaf extract is used as a reducing agent for Ag(I) conversion to Ag(0), has not been reported.…”

Eco‐friendly synthesis from industrial wastewater of Fe and Cu nanoparticles over NaX zeolite and activity in 4‐nitrophenol reduction

“…After the addition of the Fe/NaX and Cu/NaX, the color of the solution gradually changed from yellow to colourless, and the intensity of the strong adsorption peak at 400 nm gradually decreased. A new peak appeared at about 300 nm (Figure c), which corresponds to 4‐AP . An isosbestic point at 320 nm appeared in the UV‐Vis spectra (Figure a–b), indicating that the catalytic reduction of 4‐NP yields only 4‐AP without byproducts .…”

“…The catalytic reduction over Cu/NaX and Fe/NaX includes the following steps (Figure ): chemisorption of BH ‐ 4 on the Cu/NaX and Fe/NaX surface; (ii) the electron transfer from the donor BH ‐ 4 to the acceptor 4‐NP occurs, whereby the Fe 3+ and Cu 2+ react with BH ‐ 4 forming a metal hydride complex that transfers surface hydrogen species (H) and electrons (e ‐ ) to 4‐NP; (iii) two reduced intermediates, −NO and −NHOH (Figure ), form; (iv) 4‐NO reduces to 4‐AP; (v) 4‐AP desorbs from the surface of the catalyst . The reduction mechanism of 4‐NP on Fe/NaX and Cu/NaX is illustrated in Figure . …”

“…The catalytic efficiency depends on the surface structure and electron transfer properties of the catalyst; the high activity of Cu/NaX and Fe/NaX compared to NaX is related to the dispersion of Cu and Fe over the zeolite, which provides more accessible reactive sites for the reduction of 4‐NP . Moreover, the surface positive charge of zeolites facilitated the interaction between the surface and the donor species BH ‐ 4 , as well as between zeolite and the metal …”

Hetero–nanostructured Ni/α‐Mn2O3 as Highly Active Catalyst for Aqueous Phase Reduction Reactions

“…It is also used widely as a corrosion inhibitor, photographic developer, anticorrosion‐lubricant, and hair‐dyeing agent . As a result, these days researchers have paid much attention on the reduction of 4‐NP to 4‐AP in presence of mild reducing agent …”