Activation of Peroxymonosulfate by Surface-Loaded Noble Metal Nanoparticles for Oxidative Degradation of Organic Compounds

Abstract

This study demonstrates the capability of noble metal nanoparticles immobilized on Al2O3 or TiO2 support to effectively activate peroxymonosulfate (PMS) and degrade select organic compounds in water. The noble metals outperformed a benchmark PMS activator such as Co(2+) (water-soluble) for PMS activation and organic compound degradation at acidic pH and showed the comparable activation capacity at neutral pH. The efficiency was found to depend on the type of noble metal (following the order of Pd > Pt ≈ Au ≫ Ag), the amount of noble metal deposited onto the support, solution pH, and the type of target organic substrate. In contrast to common PMS-activated oxidation processes that involve sulfate radical as a main oxidant, the organic compound degradation kinetics were not affected by sulfate radical scavengers and exhibited substrate dependency that resembled the PMS activated by carbon nanotubes. The results presented herein suggest that noble metals can mediate electron transfer from organic compounds to PMS to achieve persulfate-driven oxidation, rather than through reductive conversion of PMS to reactive sulfate radical.

Peroxymonosulfate enhanced visible light photocatalytic degradation bisphenol A by single-atom dispersed Ag mesoporous g-C3N4 hybrid

“…6, the removal of BPA catalyzed by g-C 3 N 4 in the presence of PMS without irradiation was negligible, indicating the poor reactivity for PMS activation. By contrast, 10% Ag/mpg-C 3 N 4 showed the enhanced catalytic activity in the presence of PMS and 15% BPA was removed in 60 min due to the activation of PMS by metallic Ag [31]. The photocatalytic activity of g-C 3 N 4 and Ag/mpg-C 3 N 4 is also compared under visible light irradiation, and only 2% BPA was removed by g-C 3 N 4 , which is caused by its poor photocatalytic activity resulting from the rapid recombination of photogenerated electron-hole pairs.…”

Role of Nanomaterials in the Treatment of Wastewater: A Review

“…Palladium acetate and polyetherimide both are used to prepare nanocomposite films and a novel type interaction is present among hydrogen and Pd nanoparticles in order to improve water treatment efficiency [134]. In situ and ex-situ methods are also used to produce nanomaterials within the matrix with precursor film under many conditions [135][136][137]. This offers many opportunities to produce nanomaterial with tunable properties.…”

Activation of Peroxymonosulfate by Oxygen Vacancies-Enriched Cobalt-Doped Black TiO2 Nanotubes for the Removal of Organic Pollutants

“…9 The free-radical mechanism has attracted more attention, compared to the nonradical mechanism, because it can treat a broad spectrum of recalcitrant organic pollutants, given the high oxidizing potential of SO 4 • – over a broad range of pH. 10 A variety of methods have been employed to generate SO 4 • – via PMS activation. 11−19 Transition-metal ions with multiple valence state are most frequently used for activation of PMS without the need for external energy inputs (e.g., UV light and electricity).…”