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Fenton oxidation technology is a widely-used advanced oxidation technology. However, the generation of hydroxyl radicals is restrained by the sluggish recovery of Fe(II), thus affecting its long-lasting performance for water decontamination. Here, a novel niobium carbide (Nb 2 C) MXene material was applied as a green co-catalyst. Nb 2 C MXene can significantly promote Fenton reactions to produce hydroxyl radicals for degrading dimethyl phthalate (DMP) with high efficiency and high stability for long-term operation, which outperforms than various reported co-catalysts. Meanwhile, the Nb 2 C/Fe(III)/H 2 O 2 system is capable of non-selectively degrading a wide spectrum of refractory pollutants. Mechanism investigation reveals that Nb 2 C MXene as an electron donor can straight reduce Fe(III), meanwhile mediate electron shuttle from Fe(II) to H 2 O 2 to strongly expedite the generation of hydroxyl radicals. In addition, four main degradation routes of DMP were proposed. Therefore, this study offers an updated and valid strategy for the refractory organic pollutants elimination by coupling Nb 2 C MXene and Fenton oxidation. [Display omitted] • Nb 2 C MXene outperformed than a variety of co-catalysts of enhanced Fenton system. • The Nb 2 C/Fe(III)/H 2 O 2 can non-selectively degrade a wide spectrum of organic contaminants. • Nb 2 C MXene can provide electrons for direct Fe(III) reduction by cleaving Nb-C bonds. • Nb 2 C MXene can mediate electron transfer between Fe(II) and H 2 O 2 to promote Fenton reaction. [ABSTRACT FROM AUTHOR]

Herein, an electrochemical (EC) system was applied as "co-catalyst" to enhance the activation of peroxymonosulfate (EC/Fe(III)/PMS) for efficient Sulfamethoxazole (SMX) degradation. The cathodic reduction reaction can facilitate electron transfer to Fe(III) and trigger the sustainable Fe(III)/Fe(II) redox cycle. Unexpectedly, in addition to hydroxyl radical (•OH) and sulfate radical (SO 4 •−), non-radicals mechanism including singlet oxygen (1O 2) and Fe(IV) were also found involved in EC/Fe(III)/PMS system. The degradation of SMX in EC/Fe(III)/PMS system was accomplished by the collaboration of radicals and non-radicals oxidation. The generation routes and mechanisms of involved reactive oxygen species (ROS) were explored. The relative contributions of •OH, SO 4 •−, and nonradical species for the degradation of SMX were calculated to 4.75 %, 25.31 %, and 69.94 %, respectively. Besides, multiple degradation pathways of SMX were proposed by identifying the formed byproducts. The EC/Fe(III)/PMS process could efficiently degrade SMX under the influence of co-existing ions and inactivate pathogens in the wastewater. [Display omitted] • Electrochemical system was used as a "co-catalyst" to promote the Fe(III)/Fe(II) redox cycle. • SMX is effectively degraded with a weak electrical current consumption in EC/Fe(III)/PMS system. • EC/Fe(III)/PMS system is mainly a non-radical pathway dominated by 1O 2 and Fe(IV). • EC/Fe(III)/PMS system demonstrated the ability to simultaneously eliminate contaminants and pathogens. [ABSTRACT FROM AUTHOR]

In this study, N and O co-doping carbon materials with porous structure (NOPC-x) were applied to activate peroxymonosulfate (PMS) for bisphenol (BPA) degradation and the underlying effects in affecting NOPC-x activity were revealed. Electrochemical characterization, electron paramagnetic resonance (EPR) tests, quenching and PMS adsorption experiments were applied to clarify the mechanism of BPA degradation. It's found that BPA can be completely removed within 20 min (k obs = 0.30 min−1) in the NOPC/PMS system depending on the electron transfer path with the necessity of moderate surfaced unpaired electrons for electrons delivery, which could be regulated by the modifier dosage. However, excessive surfaced unpaired electrons were unfavorable to PMS adsorption, resulting in deterioration of BPA degradation. This study indicates that controlling the amount of surfaced unpaired electrons in an appropriate range is essential to ensure the carbonaceous materials activity in PMS activation to obtain a satisfactory BPA degradation. [Display omitted] ● NOPC exhibited superior activity for BPA degradation by PMS activation. ● Increasing heteroatomic doping enhanced the amount of surfaced unpaired electrons. ● Degradation of BPA was proposed to follow a nonradical electron transfer pathway. ● The role of surfaced unpaired electrons of NOPC in PMS activation was clarified. [ABSTRACT FROM AUTHOR]

Photoreforming of plastic waste is a novel approach, which can not only degrade plastic waste into valuable chemicals, but also produce high-energy-density hydrogen fuels. Here, we developed an in-situ derived carbon nitride-carbon nanotubes-NiMo hybrids via NiMo-assisted catalysis route, which works as an efficient and stable photocatalyst for plastics photoreforming. The strong π-π interaction between in-situ derived CNTs and CN promotes electron transfer, increases carrier lifetime and improves photocatalytic activity. The DFT calculations and single-particle PL quenching phenomenon confirmed the strong interface effect and charge transport for CN-CNTs-NM. In addition, the strong interaction between photocatalyst and ethylene glycol in plastics was observed in situ by single-particle PL. This work provides a smart strategy of utilizing in-situ derived π-π interaction as well as direct evidence of the charge transfer from the photocatalysts to ethylene glycol, which provides guidance for the rational design of highly efficient photocatalysts for plastics photoreforming. Photoreforming of plastics is a novel approach, which can not only degrade plastic waste into valuable chemicals, but also produce high-energy-density hydrogen fuels. Here, we developed an in-situ derived carbon nitride-carbon nanotubes-NiMo hybrids (CN-CNTs-NiMo) via NiMo self-catalytic route, which works as an efficient and stable photocatalyst for photoreforming of plastics under alkaline conditions. [Display omitted] • PET photoreforming can convert plastics into value-added chemicals and hydrogen using sunlight. • In situ-derived CN-CNTs-NM hybrids were synthesized NiMo-assisted catalysis route for photoreforming of PET. • Single-particle PL and DFT calculations confirm the existence of π-π interactions between CN and CNTs. • The real-world applicability of plastics photoreforming was confirmed by photoreforming of PET bottle. • The mechanism of plastics photoreforming was investigated in situ using single-particle PL. [ABSTRACT FROM AUTHOR]