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Here, we demonstrate an integrated fluidic sequential electrochemical system for effective water decontamination. The system consists of a Ti mesh anode deposited with nanoscale IrO 2 and a CNT filter functionalized with nanoconfined Fe 2 O 3. By conducting anodic oxygen evolution reaction (OER) and 2e– oxygen reduction reaction (ORR) sequential electrolysis, our system enables sustainable O 2 generation at the anode, followed by transformation of O 2 into H 2 O 2 at the cathode, which then led to the production of 1O 2 in the presence of nanoconfined Fe 2 O 3. No chemical inputs were needed nor side products occurred during the whole sequential electrochemical processes. The effectiveness of the system was evaluated using tetracycline as a model emerging contaminant. Recirculating at 3 mL min–1, the system exhibited negligible iron and iridium leaching (≤0.01 mg L–1) and high tetracycline degradation efficiency (≥95%). Such excellent efficacy can be maintained across a wide pH range and in complicated water matrices. [Display omitted] • An "O 2 self-feeding" fluidic bipolar electrochemical system was designed. • The system combines oxygen/water (O 2 /H 2 O) redox couple. • The system shows negligible Fe and Ir loss and high organic degradation efficiency. • The essential role of 1O 2 was identified toward selective organic degradation. • No chemical inputs were needed nor side products occurred during the reaction. [ABSTRACT FROM AUTHOR]

Oxygen vacancies (OVs)-rich α-Ni 0.2 Fe 1.8 O 3 with dual metal sites was synthesized by Ni2+ isomorphously substituted α-Fe 2 O 3 to activate peroxymonosulfate (PMS) for aceclofenac (ACF) degradation. A novel insight was proposed for the overlooked role of H 2 O in the surface-complexed process between PMS and unsaturated metal sites induced by OVs. The surface-bond SO 4 ∙- and ∙OH were demonstrated as the dominant reactive oxygen species (ROS). In situ ATR and Raman spectra revealed the reaction of HSO 5 - with the surface metal sites by replacing the surface-bonded -OH. The DFT study revealed the spontaneous formation of hydrolyzed -OH on OVs (∆G=−1.45 eV), which was further replaced by HSO 5 - to complex with metal sites (∆G=−3.58 eV). The O Ⅰ of the H-O Ⅰ -O Ⅱ -SO 3 - was more readily bonded with the Ni or Fe sites around OVs, causing the O-O cleavage for SO 4 ∙- generation. This study proposed a brand-new perspective for the interfacial behavior of PMS activation. [Display omitted] • The α-Ni 0.2 Fe 1.8 O 3 with rich oxygen vacancies can excellently activate PMS. • The surface-bond SO 4 ∙- and ∙OH played a major role in the degradation of ACF. • HSO 5 - was mainly bonded to metal sites by replacing surface -OH groups. • The interfacial mechanism for PMS activation by α-Ni 0.2 Fe 1.8 O 3 was proposed. • The degradation pathway of ACF by α-Ni 0.2 Fe 1.8 O 3 /PMS system was deduced. [ABSTRACT FROM AUTHOR]

Singlet oxygen (1O 2) plays a crucial role in Fenton-like reactions due to its high efficiency and selectivity in removing trace organic pollutants from complex water matrices. Defect engineering, which allows the efficient exposure of active sites and optimization of electronic structures, has rapidly emerged as a fundamental strategy for enhancing 1O 2 yield. Herein, we introduce tunable sulfur vacancy (V S) density into Co 9 S 8 catalysts for peroxymonosulfate (PMS) activation. The modulation of the octahedral Co (CoS 6) and tetrahedral Co (CoS 4) electronic structures by V S triggers the unexpected selective generation of 1O 2. The V S /PMS system exhibits excellent resistance to interference and highly selective degradation of electron-donating organic pollutants. Experimental and theoretical calculations revealed a new evolutionary route for 1O 2 involving two phases (Phase I: HSO 5 − → *O, Phase II: *O + HSO 5 − →*OO → 1O 2). This study provides a molecular-level understanding of V S -mediated catalytic selectivity for high-efficient decontamination applications. [Display omitted] • Co 9 S 8 catalysts with tunable V S was fabricated to PMS activation for contaminants degradation. • The optimized V S /PMS system achieved 1O 2 -dominated degradation mechanism. • Regulation d-band center of Co-3d orbital boosted the process of HSO 5 − adsorption and activation. • Combining experiment and DFT results revealed a new evolutionary route of 1O 2. [ABSTRACT FROM AUTHOR]

Developing catalysts with high efficiency and excellent interference tolerance for practical application remains a challenge in catalytic ozonation process. Herein, the surface Vo-rich catalyst was successfully prepared by lattice-doping Co into zinc ferrite spinel, which exhibited efficient mineralization of recalcitrant organic pollutants. The contaminants removal was mainly attributed to the nonradical-based oxygen species of surface atomic oxygen (*O) rather than traditional hydroxyl radical (· OH). The experiments and DFT calculation results revealed that Vo was the main active sites for adsorption of ozone and production of *O. The O-O in ozone was dissociated at Vo, trigging the formation of *O. In addition, the Vo-driven nonradical catalysis showed high resistance to the coexisting ions (200 mM Cl-, SO 4 2- and NO 3 -) and exhibited excellent performance for actual wastewater treatment. This work provides a novel strategy to regulate the oxidation pathways in catalytic ozonation process for efficient mineralization of pollutants in complicated water matrices. [Display omitted] • The oxidation pathway can be regulated by the introduction of Vo. • Vo acted as the main active sites for the adsorption and activation of ozone. • The nonradical species of *O played major role in pollutants removal. • The catalyst with enriched Vo exhibited efficient mineralization of ibuprofen. • Vo-driven nonradical catalysis showed high resistance to the coexisting ions. [ABSTRACT FROM AUTHOR]

Palladium recycling offers a sustainable and economic approach to meet the rising global demand of this precious yet naturally scarce metal. Here, we demonstrate a new recovery concept that utilizes a bipyridine-based adsorptive membrane (AM) based on covalent organic frameworks (COFs). This approach enables selective recovery of palladium via local coordination and electrostatic interaction, followed by in situ reduction to form a palladium nanolayer within the COF AM. Simulation and experimental results demonstrate that palladium nanoparticles with narrow size distributions were evenly enriched and localized within the continuous, 33-nm-thick COF nanofilm. This palladium enrichment step further provided high catalytic activity (99.9 % conversion of 4-nitrophenol) to the nanofilms, which maintained an ultrahigh water permeability (226.0 L m−2 h−1 bar−1). These multifunctional properties outperform state-of-the-art catalytic membranes. This study opens new directions in recovering and repurposing palladium waste into catalytic membranes, using COF membranes that efficiently decontaminate water. [Display omitted] • The COF-based adsorptive membrane enabled selective capture of precious palladium. • Theoretical calculations showed an annular Pd distribution along the COF pore wall. • Palladium NPs were evenly localized within the continuous, 33-nm-thick COF nanofilm. • The COF-based catalytic membrane exhibited unprecedented catalytic performance. • These catalytic membranes show superior antibacterial activity against E. coli. [ABSTRACT FROM AUTHOR]

Sulfate radicals (SO 4 •-) reactivity against gram-negative (E. coli) and gram-positive (E. faecalis) bacteria and Contaminants of Emerging Concern (CECs) (Diclofenac-DCF, Sulfamethoxazole-SMX and Trimethoprim-TMP) was investigated through laser flash photolysis (LFP) technique. Analysis of the lifetime of SO 4 •- in presence of cell-wall compounds of bacteria and CECs allowed determining reactivity of SO 4 •- towards these compounds. Results showed that SO 4 •- reacts with common cell-wall components through H-abstraction mechanism (k SO4•− < 108 M-1s-1). By contrast, k SO4•− > 109 M-1s-1 were found using aromatic amino acids (AAA) only present in Porins of the gram-negative outer-membrane. The intermediates detected from the reaction of SO 4 •- with the AAA confirmed the involvement of electron transfer processes. Moreover, k SO4•− values determined for DCF, TMP and SMX also agreed with an electron transfer mechanism. Interestingly, bacteria and CECs removal at pilot plant scale by UV-C/SO 4 •- is in accordance with the k SO4•− obtained using the LFP: E. coli > E. faecalis and DCF > TMP ≅ SMX. [Display omitted] • LFP as a tool to investigate SO 4 •- reactivity towards biological and chemical targets. • SO 4 •- reacts through H abstraction with the cell wall constituents with k SO4•−,Q of 107 M-1s-1. • SO 4 •- reacts by e- transfers with amino acids, making gram negative bacteria more susceptible to SR-AOP. • CECs quickly reacted with SO 4 •-, showing k SO4•− of 109 M-1s-1 through e- transfer mechanism. • UVC/PS results at pilot plant scale confirm feasibility of SR-AOP to decontaminate and disinfect water. [ABSTRACT FROM AUTHOR]

Here we report an integrated reduced graphene oxide/polypyrrole hybrid aerogel with highly efficient photodegradation performance and ultrahigh solar-powered water evaporation for simultaneous freshwater production and decontamination from complex wastewater. The nanohybrids were successfully fabricated by the combined hydrothermal reduction and freeze-drying process. The π-π interactions between two components not only prevent the stacking of reduced graphene oxide nanosheets to endow aerogels with abundant water transport channels and ideal mechanical stability, but also facilitate the interactions with organic molecules to realize high removal efficiency toward volatile organic compounds (VOCs). The wide-spectrum light harvesting, photothermal effect and solar-driven photocatalysis in the hybrid aerogel are beneficial for the synergistically enhanced thermal-assisted photodegradation toward VOC-contaminated water with a water evaporation rate of 2.08 kg m−2 h−1 and a phenol removal efficiency of 94.8%. Our findings may help the development of novel functional nanostructures for applications in environmental remediation and solar steam generation. [Display omitted] • An integrated graphene/polypyrrole hybrid aerogel was successfully fabricated. • π-π conjugation prevents the self-stacking of graphene and endows high rigidity. • The aerogel demonstrates high efficiency for pollutant degradation and water evaporation. • The superior activity is ascribed to the synergy of photocatalysis and photothermal effect. [ABSTRACT FROM AUTHOR]

[Display omitted] • Anchoring cobalt on sandwich-like 2D MXene shows synergistic effect on PAA activation. • Highly efficient degradation of 2,4-DCP is observed at neutral condition. • Ti 3 C 2 T x MXene substrate accelerates recycling of ≡ Co(III)/≡ Co(II). • Acetylperoxyl radical is primarily responsible for contaminant degradation. • The Co@MXenes/PAA process was unaffected by water matrices. A novel Co@MXenes catalyst with unique structure was prepared through randomly anchoring cobalt on 2D sandwich-like MXenes to activate peracetic acid (PAA) for water decontamination. Compared to the conventional Co 3 O 4 nanomaterial, the Co@MXenes catalyst exhibits superior performance for PAA activation under neutral condition. In-depth investigation revealed that the Ti 3 C 2 T x MXene substrate triggered the ≡ Co(III)/≡ Co(II) cycle, which greatly enhanced the activation of PAA. The XPS and ICP techniques further demonstrated that Co@MXenes was highly stable with extremely low cobalt ion leaching and hence a superior reusability was obtained. Moreover, acetylperoxyl radical (CH 3 CO 3 ) was identified as the primary radical species responsible for organic micropollutants degradation, exhibiting high selectivity towards contaminants containing electron-rich groups. The novel technology exhibited a high tolerance of Cl− and good performance in real wastewater treatment. This work provides a promising effective catalyst for PAA activation and will facilitate PAA application in wastewater decontamination. [ABSTRACT FROM AUTHOR]