Fenton‐like degradation of rhodamine B over highly durable Cu‐embedded alumina: Kinetics and mechanism

Abstract

in Wiley Online Library (wileyonlinelibrary.com)Cu-embedded mesoporous alumina, as a Fenton-like catalyst prepared via a sol-gel method, showed excellent activity and durability for the degradation of refectory compounds. The origin of active sites for the generation of hydroxyl radicals (•OH) were thoroughly studied using multitechniques. Cu, as the only active element, could be penetrated into the bulk of alumina and some Cu atoms were embedded into the framework. The dynamic structure of surface Cu species (the variety of Cu 1 /Cu 21 ratio) during the reaction were determined as well. Furthermore, the structure plasticity of catalyst has proved by optimizing preparation and reaction conditions. A 98.53% degradation of RhB was recorded within 30 min, following a pseudo-first-order reaction rate expression. Electron spin resonance spectra and •OH scavenging experiments have confirmed that •OH is the main reactive oxidant for the elimination of RhB. By the surfaceenhanced Raman spectroscopy and gas chromatography-mass spectrometer results, plausible pathways of RhB degradation were elaborated.

Copper/carbon composites from waste printed circuit boards as catalysts for Fenton‐like degradation of Acid Orange 7 enhanced by ultrasound

“…The degradation efficiency at 60 min in the presence of methanol, ethanol, and butyl alcohol is 42.34%, 45.66%, and 52.96%, respectively. The inhibition for AO7 degradation is attributed to scavenging •OH radicals by methanol, ethanol, and butyl alcohol, confirming the important role of •OH radicals in the catalytic process …”

“…The Fenton‐like degradation of AO7 highly depends on •OH radicals, which are generated via H 2 O 2 activation . The effect of H 2 O 2 dosage on AO7 degradation is shown in Figure .…”

“…In an acidic solution, the positively charged surface of PCB 500 caused by protonation of surface groups facilitates AO7 adsorption through electrostatic interaction, whereas more Cu 2+ ions are produced due to copper leaching from PCB 500 . However, the solvation of H 2 O 2 at low pH generates stable [H 3 O 2 ] + ions and inhibits production of •OH radicals, thus causing relatively low AO7 degradation . In addition, PCB 500 shows high catalytic activity for the AO7 degradation in the pH range of 4.3–6.8.…”

“…To identify the role of •OH radicals in the PCB 500 /US/H 2 O 2 system, radical scavengers including methanol, ethanol, and butyl alcohol were tested . As shown in Figure , radical scavengers negligibly influence AO7 removal from aqueous solutions.…”

Kinetic and Mechanistic Study of Rhodamine B Degradation by H2O2 and Cu/Al2O3/g-C3N4 Composite

“…The peaks at 931.7 eV, 933.6 eV, and 941.5 eV still represent Cu + , Cu 2+ , and satellite peaks of copper species, respectively. The Cu + to Cu 2+ ratio on the Cu/Al 2 O 3 /CN composite was 2.34 before reaction and decreased to 1.42 after reaction, indicating that copper species were the active sites and the conversion of Cu + to Cu 2+ was involved in the reaction [48].…”