Photocatalysis of fenoxycarb over silver-modified zeolites

Abstract

Two samples of silver doped into zeolite Y were prepared and characterized. ICP and SEM-EDS analysis indicate that the AgY1 sample contains twice the amount of silver compared to the AgY2 sample. Solid state luminescence spectroscopy shows variations in the emission modes of the site-selective luminescence where various luminophores might be excited upon selecting the proper excitation energy. The selected material effectively decomposed the pesticide fenoxycarb in aqueous solution. The photodecomposition of fenoxycarb reached 80 % upon irradiation for 60 min in the presence of the AgY1 catalyst. 2-(4-Phenoxy-phenoxy)ethyl] carbamic acid (1) and 1-amine-2-(phenoxy-4-ol) ethane (2) were identified as products for both uncatalyzed solution and the catalyzed fenoxycarb with AgY2 catalyst. Whereas, compound (2) was the only product identified in the catalyzed reaction with AgY1.

The Photocatalytic Degradation of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin in the Presence of Silver–Titanium Based Catalysts

“…Instead, it is a clear indication of the excimer formation upon exciting the TCDD molecule in the presence of the AgTi surface. The excited state bonding between adjacent units (called an Excimer) is well known for planar conjugated molecules like anthracene as well as the metal-metal excimers in the case of silver clusters [23][24][25][26][27][28][29][30][31]. The adsorbed TCDD on the surface provides a suitable orientation for two adjacent TCDD units to establish electron transfer from a TCDD π-electrons to the excited conjugated π-π* bond in another molecule which leads to the dimer (excimer formation).…”