Photocatalytic Degradation of 2,4,6-Trichlorophenol by MgO–MgFe2O4 Derived from Layered Double Hydroxide Structures

Abstract

In recent years, the search for solutions for the treatment of water pollution by toxic compounds such as phenols and chlorophenols has been increasing. Phenols and their derivatives are widely used in the manufacture of pesticides, insecticides, paper, and wood preservers, among other things. Chlorophenols are partially biodegradable but not directly photodegradable by sunlight and are extremely toxic—especially 2,4,6-trichlorophenol, which is considered to be potentially carcinogenic. As a viable proposal to be applied in the treatment of water contaminated with 2,4,6-trichlorophenol, this paper presents an application study of the thermally activated Mg/Fe layered double hydroxides as photocatalysts for the mineralization of this contaminant. Activated Mg/Fe layered double hydroxides were characterized by X-ray diffraction, thermal analysis, N2 physisorption, and scanning electron microscopy with X-ray dispersive energy. The results of the photocatalytic degradation of 2,4,6-trichlorophenol in aqueous solution showed good photocatalytic activity, with an efficiency of degradation of up to 93% and mineralization of 82%; degradation values which are higher than that of TiO2-P25, which only reached 18% degradation. The degradation capacity is attributed to the structure of the MgO–MgFe2O4 oxides derived from double laminate hydroxide Mg/Fe. A path of degradation based on a mechanism of superoxide and hollow radicals is proposed.

Photocatalytic Degradation of Toxic Phenolic Compound and Bacterial Inactivation by Ternary Li doped Zn0.5Ni0.5Fe2O4

“…During the dark state, the rich metal sites may react with the bacteria membrane, causing cell leakage. Although the specific mechanism of the Li/antibacterial ZNF′s activity is unknown, the discussion is consistent with earlier studies [42–47] . In Table 1, the performance of Li/ZNF is compared to that of other reported doped materials.…”

“…Although the specific mechanism of the Li/ antibacterial ZNF's activity is unknown, the discussion is consistent with earlier studies. [42][43][44][45][46][47] In Table 1, the performance of Li/ZNF is compared to that of other reported doped materials. The results reveal that Li/ZNF has comparatively greater performance.…”

Photoelectrocatalytic Degradation of Congo Red Dye with Activated Hydrotalcites and Copper Anode

“…Figure 1 shows the laminar structure of a hydrotalcite Mg/Al with carbonate ions and water molecules in the interlaminar space. Due to its anion exchange capacity in the interlaminar space, hydrotalcites have been used to remove from water mono-, di-, and polyvalent anions, organochlorine compounds [30,31], heavy metals [32,33], and synthetic dyes [5,[34][35][36]. In addition, the chemical composition of hydrotalcites, as well as their physicochemical properties, have allowed their application in various areas such as catalysis [37], electrocatalysis [38,39], energy storage [40,41], and photocatalysis [5,29,31].…”

Optimised Photocatalytic Degradation of Crystal Violet Over 1wt% MgO-ZnO Composite Catalyst

“…MgO has a wide band gap in the bulk form (7.8 eV), and unlike CeO2, it is a non-toxic material. Recently, this oxide has been variously used in highly photoactive nanocomposites such as ZnO-ZnMgO-MgO [17], MgO-MgFe2O4 [18] and MgO/g-C3N4 [19].…”