Electron Delocalization Realizes Speedy Fenton-Like Catalysis over a High-Loading and Low-Valence Zinc Single-Atom Catalyst.

A zinc (Zn)-based single-atom catalyst (SAC) is recently reported as an active Fenton-like catalyst; however, the low Zn loading greatly restricts its catalytic activity. Herein, a molecule-confined pyrolysis method is demonstrated to evidently increase the Zn loading to 11.54 wt.

Turning the Inert Element Zinc into an Active Single-Atom Catalyst for Efficient Fenton-Like Chemistry.

Amongst various Fenton-like single-atom catalysts (SACs), the zinc (Zn)-related SACs have been barely reported due to the fully occupied 3d configuration of Zn being inactive for the Fenton-like reaction. Herein, the inert element Zn is turned into an active single-atom catalyst (SA-Zn-NC) for Fenton-like chemistry by forming an atomic Zn-N coordination structure. The SA-Zn-NC shows admirable Fenton-like activity in organic pollutant remediation, including self-oxidation and catalytic degradation by superoxide radical (O ⋅ ) and singlet oxygen ( O ).

Low Concentration of Peroxymonosulfate Triggers Dissolved Oxygen Conversion over Single Atomic Fe-N O Sites for Water Decontamination.

Achieving satisfactory organic pollutant oxidation with a low concentration of peroxymonosulfate (PMS) is vital for persulfate-involved advanced oxidation processes to reduce resource consumption and avoid excessive sulfate anion (SO ) production. Herein, efficient conversion of dissolved oxygen (DO) over single-atomic Fe-N O sites anchored on carbon nitride for efficient contaminant degradation is fulfilled, triggered by a low concentration of PMS (0.2 mm).

Cation-π induced surface cleavage of organic pollutants with OH formation from HO for water treatment.

High energy consumption is impedimental for eliminating refractory organic pollutants in water by applying advanced oxidation processes (AOPs). Herein, we develop a novel process for destructing these organics in chemical conjuncted Fe-FeC/Fe, graphited ZIF-8, and rGO air-saturated aqueous suspension without additional energy. In this process, a strong Fe-π interaction occurs on the composite surface, causing the surface potential energy ∼310.

Unraveling the High-Activity Origin of Single-Atom Iron Catalysts for Organic Pollutant Oxidation via Peroxymonosulfate Activation.

Single-atom catalysts (SACs) have emerged as efficient materials in the elimination of aqueous organic contaminants; however, the origin of high activity of SACs still remains elusive. Herein, we identify an 8.1-fold catalytic specific activity (reaction rate constant normalized to catalyst's specific surface area and dosage) enhancement that can be fulfilled with a single-atom iron catalyst (SA-Fe-NC) prepared via a cascade anchoring method compared to the iron nanoparticle-loaded catalyst, resulting in one of the most active currently known catalysts in peroxymonosulfate (PMS) conversion for organic pollutant oxidation.

Enhanced Fenton-like efficiency by the synergistic effect of oxygen vacancies and organics adsorption on FeO-d-g-CN with Fe‒N complexation.

d-g-CN-Fe composites was prepared via a self-assembly and calcination process. According to measurements and density functional theory (DFT) computations, the complexation of iron and pyridinic N of g-CN (Fe‒N) occurred with Fe(III)-π interaction, causing more oxygen vacancies (OVs) with more electrons in iron oxides. In the catalyst air-saturated suspension, the adsorbed pollutants complexed surface Fe(III) through their hydroxyl group donated electrons to around OVs, reducing the surface Fe(III) to Fe(II) and were destructed by Fe(III)-π interaction of the complexation.

Enhancing inhibition of disinfection byproducts formation and opportunistic pathogens growth during drinking water distribution by FeO/Coconut shell activated carbon.

The effects of biological activated carbon treatment using FeO modified coconut shell-based activated carbon (Fe/CAC) were investigated on the occurrence of opportunistic pathogens (OPs) and formation of disinfection by-products (DBPs) in simulated drinking water distribution systems (DWDSs) with unmodified CAC as a reference. In the effluent of annular reactor (AR) with Fe/CAC, the OPs growth and DBPs formation were inhibited greatly. Based on the differential pulse voltammetry and dehydrogenase activity tests, it was verified that extracellular electron transfer was enhanced in the attached biofilms of Fe/CAC, hence improving the microbial metabolic activity and biological removal of organic matter especially DBPs precursors.

General synthesis of carbon and oxygen dual-doped graphitic carbon nitride via copolymerization for non-photochemical oxidation of organic pollutant.

Earth-abundant, environmental-benign and durable catalysts are of paramount importance for remediation of organic pollutants, and graphitic carbon nitride (g-CN) is a promising nonmetallic material for this application. However, the catalytic oxidation on g-CN suffers from low efficiency because of its chemical inertness if not irradiated with light. Herein, we develop a facile copolymerization strategy for the synthesis of carbon and oxygen dual-doped g-CN using urea as g-CN precursor and ascorbic acid (AA) as carbon and oxygen sources, which induces electronic structure reconfiguration.

Efficient removal of disinfection by-products precursors and inhibition of bacterial detachment by strong interaction of EPS with coconut shell activated carbon in ozone/biofiltration.

The change of water quality was investigated in pilot-scale ozone-biological activated carbon (O-BAC) filters using an emerging coconut shell-based granular activated carbon (CAC) or traditional granular activated carbon (GAC), respectively. More dissolved organic carbon (DOC) and disinfection by-products (DBPs) precursors were removed, meanwhile, less microbes, less metabolites and smaller microbial clusters were detected in the effluent of CAC compared with GAC. Sequentially, lower DBPs formation and higher disinfection efficiency were achieved in drinking water distribution systems (DWDSs).

Highly nitrogen-doped porous carbon transformed from graphitic carbon nitride for efficient metal-free catalysis.

Nitrogen-doped carbon materials are proposed as promising metal-free catalysts for persulfate-mediated catalytic oxidation process, yet the nitrogen content in the final carbon products is typically low. Moreover, controversies remain in the unambiguous identification of active sites in nitrogen-doped carbons for persulfate activation. Here we report the facile synthesis of nitrogen-doped carbon material via one-step pyrolysis of urea and D-mannitol, which simultaneously combine ultrahigh nitrogen content (up to 33.

New Insights into the Generation of Singlet Oxygen in the Metal-Free Peroxymonosulfate Activation Process: Important Role of Electron-Deficient Carbon Atoms.

A nonradical oxidation process via metal-free peroxymonosulfate (PMS) activation has recently attracted considerable attention for organic pollutant degradation; however, the origin of singlet oxygen (O) generation still remains controversial. In this study, nitrogen-doped carbon nanosheets (NCN-900) derived from graphitic carbon nitride were developed for activation of PMS and elucidation of O production. With a large specific surface area (1218.

Electronic Structure Modulation of Graphitic Carbon Nitride by Oxygen Doping for Enhanced Catalytic Degradation of Organic Pollutants through Peroxymonosulfate Activation.

Oxygen-doped graphitic carbon nitride (O-CN) was fabricated via a facile thermal polymerization method using urea and oxalic acid dihydrate as the graphitic carbon nitride precursor and oxygen source, respectively. Experimental and theoretical results revealed that oxygen doping preferentially occurred on the two-coordinated nitrogen positions, which create the formation of low and high electron density areas resulting in the electronic structure modulation of O-CN. As a result, the resultant O-CN exhibits enhanced catalytic activity and excellent long-term stability for peroxymonosulfate (PMS) activation toward the degradation of organic pollutants.

Highly improved photoelectrocatalytic efficiency and stability of WO photoanodes by the facile in situ growth of TiO branch overlayers.

The development of highly efficient and stable visible-light-responsive photoanode materials is essential for practical photoelectrocatalytic (PEC) applications. In this work, a novel method was proposed to enhance the PEC efficiency and stability of WO3 photoanodes by the facile in situ growth of TiO2 branch overlayers on WO3 nanoplates (TWNP) based on the lattice match between monoclinic WO3 and anatase TiO2. The WO3 nanoplates (WNP) with a fluted body and a thickness of 160 nm were first prepared on tungsten foil by a hydrothermal method.

Catalyst-free activation of peroxides under visible LED light irradiation through photoexcitation pathway.

Catalysts are known to activate peroxides to generate active radicals (i.e., hydroxyl radical (OH) and sulfate radical (SO)) under certain conditions, but the activation of peroxides in the absence of catalysts under visible light irradiation has been rarely reported.

Iron modified bentonite: Enhanced adsorption performance for organic pollutant and its regeneration by heterogeneous visible light photo-Fenton process at circumneutral pH.

Iron modified bentonite (FeMB) was prepared and used as an inexpensive adsorbent to rapidly remove organic pollutant (Rhodamine B, RhB) from aqueous solution. The iron modification significantly improved the adsorption performance of FeMB for RhB and permitted an easy separation of FeMB from the treated effluent. The equilibrium adsorption studies indicated that the dye molecules obeyed Langmuir type of adsorption with the calculated maximum adsorption capacity of 168.