A unique Si-doped carbon nanocatalyst for peroxymonosulfate (PMS) activation: insights into the singlet oxygen generation mechanism and the abnormal salt effect

Abstract

The heteroatom-doped, carbon-activated peroxymonosulfate (PMS) system proceeding via the non-radical oxidation pathway involving singlet oxygen (1O2) represents a promising advanced oxidation process (AOP) due to the resistance of 1O2 to...

Degradation of Aqueous Quinoline Using Persulfate Activated by γ‐Fe2O3@Carbon Composites and Enhanced by UV Irradiation

“…Additionally, CO 3 2À , which is identified as an exclusive quencher of superoxide radical (O 2 *À ) was used to study the formation mechanism of 1 O 2 . [20] As can be seen from Figure 2(c), the removal efficiency of quinoline was significantly reduced in the presence of 20 mM CO 3 2À , indicating that O 2 *À may be the key intermediate product for the formation of 1 O 2 in the UV-γ-Fe 2 O 3 @C/PS system, which was consistent with the γ-Fe 2 O 3 @C/ PS system [12] and most of other research. [21] ESR measurement was taken to further identify the reactive oxygen species in the γ-Fe 2 O 3 @C/PS system and UV-γ-Fe 2 O 3 @C/PS system by employing 5,5-Dimethyl-1-pyrroline Noxide (DMPO) as the trapping agent for SO 4 *À , * OH and 2,2,6,6teramethylpiperidine (TEMP) as the trapping agent for 1 O 2 .…”

“…The inhibition effect of L‐histidine confirmed the existence of 1 O 2 in the UV‐ γ ‐ Fe 2 O 3 @C/PS system. Additionally, CO 3 2− , which is identified as an exclusive quencher of superoxide radical (O 2 .− ) was used to study the formation mechanism of 1 O 2 [20] . As can be seen from Figure 2(c), the removal efficiency of quinoline was significantly reduced in the presence of 20 mM CO 3 2− , indicating that O 2 .− may be the key intermediate product for the formation of 1 O 2 in the UV‐ γ ‐Fe 2 O 3 @C/PS system, which was consistent with the γ ‐Fe 2 O 3 @C/PS system [12] and most of other research [21]…”

SnO2–x Nanoparticles Decorated on Graphitic Carbon Nitride as S-Scheme Photocatalysts for Activation of Peroxymonosulfate

“…In the literature, there are strategies to treat the organic dyes in water, such as biological, nitrification and denitrification, physical and chemical methods, adsorption, physical filter, and photocatalysis . Among them, photocatalysis based on nanomaterials is a promising method because of its low cost, high stability at ambient pressure, and less secondary pollution. − Recently, advanced oxidation processes (AOPs) based on the visible-light-driven photocatalysis of semiconductors are a current topic in the wastewater treatment field thanks to their high performance and low costs compared to other methods. , In particular, AOPs by the activation of potassium peroxymonosulfate (PMS) are considered as a new route because of forming sulfate anion radicals ( • SO 4 – ) which are more reactive than hydroxyl radicals ( • OH), with E 0 (SO 4 • – /SO 4 2– ) = +2.5–3.1 V NHE , and *OH (E 0 (*OH/ – OH) = +1.8–2.7 V NHE . , In addition, AOPs based on • SO 4 – anion radicals have other advantages such as the use at wider pH conditions (2.0–8.00), longer half-life, and higher oxidation ability in other buffer solutions (carbonate and phosphate buffer). − There are many methods to active PMS such as thermolysis, electrolysis, photocatalysis, and metal oxidation . Recently, an S-scheme photocatalyst model has been introduced, including an oxidation photocatalyst (OP) and reduction photocatalyst (RP) with highly different work functions to enhance reduction and oxidation abilities of each photocatalyst .…”

“…10,11 In addition, AOPs based on • SO 4 − anion radicals have other advantages such as the use at wider pH conditions (2.0−8.00), longer half-life, and higher oxidation ability in other buffer solutions (carbonate and phosphate buffer). 12−14 There are many methods to active PMS such as thermolysis, 15 electrolysis, 16 photocatalysis, 17 and metal oxidation. 18 Recently, an S-scheme photocatalyst model has been introduced, including an oxidation photocatalyst (OP) and reduction photocatalyst (RP) with highly different work functions to enhance reduction and oxidation abilities of each photocatalyst.…”

Reactive oxygen species on transition metal-based catalysts for sustainable environmental applications

“…11b). 160 The activation energy for the self-decomposition of PMS in water to give 1 O 2 (HSO 5 − + SO 5 2− → SO 4 2− + HSO 4 − + 1 O 2 ) is low, 161,162 but the rate constant of this reaction is also low (0.2 M −1 s −1 ) and the selective generation of 1 O 2 is thus challenging. In activating PMS, OVs with localized electrons serve as the active sites for the heterolysis of PMS to generate 1 O 2 .…”