Excellent Degradation Performance Research Articles

Electron transfer mediated activation of periodate by contaminants to generate 1O2 by charge-confined single-atom catalyst.

The electron transfer process (ETP) is able to avoid the redox cycling of catalysts by capturing electrons from contaminants directly. However, the ETP usually leads to the formation of oligomers and the reduction of oxidants to anions. Herein, the charge-confined Fe single-atom catalyst (Fe/SCN) with Fe-N3S1 configuration was designed to achieve ETP-mediated contaminant activation of the oxidant by limiting the number of electrons gained by the oxidant to generate 1O2. The Fe/SCN-activate periodate (PI) system shows excellent contaminant degradation performance due to the combination of ETP and 1O2. Experiments and DFT calculations show that the Fe/SCN-PI* complex with strong oxidizing ability triggers the ETP, while the charge-confined effect allows the single-electronic activation of PI to generate 1O2. In the Fe/SCN + PI system, the 100% selectivity dechlorination of ETP and the ring-opening of 1O2 avoid the generation of oligomers and realize the transformation of large-molecule contaminants into small-molecule biodegradable products. Furthermore, the Fe/SCN + PI system shows excellent anti-interference ability and application potential. This work pioneers the generation of active species using ETP's electron to activate oxidants, which provides a perspective on the design of single-atom catalysts via the charge-confined effect.

Hydroxylated SiO2-modified {0 0 1}-TiO2 nanosheets as a surface multifunctional photocatalyst for enhanced degradation of gaseous toluene

The relatively weak activity and serious deactivation of anatase TiO2 nanosheet catalysts with highly exposed {001} facets ({001}-TiO2) limits its wide application in photocatalytic degradation of gaseous pollutants. Herein, we propose a hybrid photocatalyst composed of {001}-TiO2 and SiO2 with numerous hydroxyl groups (denoted as {001}-TiO2/HO-SiO2). The catalyst showed excellent performance for gaseous toluene degradation under UV illumination, with 99.2 % removal efficiency and 204.7 μmol L−1 CO2 yield (about 85.9 % mineralization efficiency) within 120 min. It also demonstrated superior durability over five consecutive cycles of toluene photodegradation. The modification of HO–SiO2 on {001}-TiO2 facilitate the selective adsorption of toluene on the catalyst surface by H-bonding interaction, and make the major poisoning species, benzoic acid, easily desorb from the surface, reducing the catalyst inactivation. Most importantly, we found that the formed TiOSi bond promotes the separation of photogenerated electron–hole pairs, and provides abundant available electrons for the formation of reactive oxygen radicals and the left holes for the conversion of toluene to benzyl radicals or oxidation of H2O to hydroxyl radicals, which results in the improved activity. This study highlights the importance of the introduction of secondary components with special functions on TiO2, which is helpful for the design of photocatalysts with high performance and anti-deactivation ability for treatment of volatile organic compounds.

Enhanced visible-light photocatalytic performance of hollow Bi/Bi4Ti3O12 microspheres assembled with Bi4Ti3O12 nanosheets and Bi nanodots synthesized by hydrothermal method

Bi4Ti3O12 (BTO) microspheres were synthesized by a facile hydrothermal method, and 2-methoxyethanol was used as reductant for formation of Bi nanodots on BTO nanosheet surfaces. The morphology evolution and photocatalytic mechanism of Bi/BTO (B/BTO) composites were explored. As the B/BTO composite was synthesized at 200oC for 72h, the hollow B/BTO microspheres assembled with BTO nanosheets and Bi nanodots were formed due to the Ostwald-ripening mechanism. For the hollow B/BTO microsphere composites, the hollow-microsphere structure increased the surface area and the multiple internal reflections of light to enhance the light utilization efficiency, and the formation of B/BTO interfaces improved the separation efficiency of photogenerated carriers and efficient charge transfer. When the 2-methoxyethanol content in the Bi-Ti precursor was 2ml, the as-prepared hollow B/BTO microspheres exhibited excellent photocatalytic performance for TC degradation under visible-light irradiation due to the synergistic effect of hollow-microsphere structure and Bi nanodot decoration.

Sol-gel preparation and visible-light-driven photocatalytic activity of the double perovskite Sr2FeMoO6

Sr2FeMoO6 was synthesized as a visible-light-driven photocatalytic double perovskite by a simple sol-gel preparation method. In-depth experimental techniques were used to characterize morphological and optical properties. Scanning and transmission electron microscopy revealed a tubular shape morphology, resulting in a large active surface area for improved photocatalysis. Optimization of Sr2FeMoO6 achieved a narrow bandgap of 1.77 eV, capable of interacting with visible light. The decomposition of methylene blue (MB) under visible-light irradiation was employed to assess the photocatalytic performance of as-synthesized samples.The Sr2FeMoO6 samples exhibited excellent degradation performance, demonstrating a 95.6% degradation of MB within 35 min of irradiation. This work has certain research significance by revealing the potential mechanism of double perovskite photocatalysts.

One-step synthesis of magnetic catalysts containing Mn3O4-Fe3O4 from manganese slag for degradation of enrofloxacin by activation of peroxymonosulfate

Landfill disposal of manganese slag is a significant environmental concern on both local and global levels. Using manganese slag to synthesis catalysts to degrade organic pollutants in wastewater is a promising pathway for the solid waste treatment. Here, we propose a simple method to prepare magnetic catalysts containing Mn3O4-Fe3O4 (MMF) using manganese slag as raw materials. The MMF exhibits excellent degradation performance for enrofloxacin (ENR) with 97 % removal efficiency within 30 min and can be rapidly isolated from wastewater by magnet. Electron paramagnetic resonance (EPR) and quenching experiments demonstrated that 1O2 produced by the non-radical pathway is the principal active substance for ENR degradation. X-ray photoelectron spectroscopy (XPS) and density-functional theory (DFT) calculations indicate that Mn and Fe in MMF provide electrons for PMS activation and that the presence of Fe promotes the activation of the PMS and the cycling of Mn. This work paves the way for developing magnetic catalysts from manganese slag for the treatment of organic pollutants via advanced oxidation process.

Dynamic covalent epoxy network of hyperbranched-synergistic-supramolecular: Catalyst-free reprocessing, and application in carbon fiber composites recycling

Plastic recycling, especially the recycling of thermosets, is a crucial step towards improving waste management and achieving economic recycling. Here, a method utilizing non-covalent supramolecular interactions and synergistic hyperbranched structures is reported to endow transesterification-based thermosetting materials with recyclability in the absence of a catalyst. A hyperbranched epoxy resin curing agent (HPCA) containing amide bonds, terminated by amine and ester, was designed and synthesized, and further cured with bisphenol A epoxy resin. The hyperbranched topological structure and its abundant amide bonds contribute to the formation of a dense hydrogen bonding network, enhancing the reprocessability, thermal, and mechanical properties of the material. As a result, the resin can be reprocessed by hot pressing at 190 °C and 10 MPa for 40 min without catalyst. Moreover, amide and ester bonds endow resin materials with excellent degradation performance in alkaline solutions, laying the foundation for the recycling and utilization of carbon fibers in composite materials.

Viologen-Directed Silver-Thiocyanate-Based Photocatalyst for Rhodamine B Degradation in Artificial Seawater.

Photocatalytic degradation is a leading technology for complete mineralization of organic dyes in the ocean. In this work, a new viologen-bearing silver-thiocyanate-based photocatalyst, i.e., {(i-PrV)[Ag2(SCN)4]}n (i-PrV2+ = isopropyl viologen) has been synthesized and structurally determined, with results showing that it can exhibit excellent degradation performance on rhodamine B (RhB) in artificial seawater. The planar i-PrV2+ dications are confined in the free voids of the [Ag2(SCN)4]n2n- layer with a two-dimensional (6,3) mesh, and strong C-H···S hydrogen bonds contribute to its structural stabilization. This photocatalyst was further characterized by powder X-ray diffraction (PXRD), UV-Vis, fluorescence, and photo/electrical responsive measurements, pointing to its application in visible-light-driven catalysis. Interestingly, using this photocatalyst, good photocatalytic degradation performance on rhodamine B in artificial seawater could be observed. The dye pollutant could be degraded with a high degradation ratio of 87.82% in 220 min. This work provides a promising catalyst for organic dye-type ocean pollutant treatments.

Low-temperature hydrothermal self-assembly synthesis of ZnIn2S4/chitosan-graphene aerogels for enhanced aqueous pollutants removal

A novel visible-light-responsive ZnIn2S4/chitosan graphene aerogel (ZCGA) was prepared using a low-temperature hydrothermal self-assembly method for the adsorption and degradation of tetracycline. Infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) indicated interactions between ZnIn2S4 and chitosan graphene aerogel (CGA). Under the irradiation of a 500 W xenon lamp, ZCGA exhibited excellent adsorption and photocatalytic degradation performance for tetracycline, with a removal rate exceeding 90 % within 180 min. This significant performance improvement is attributed to the high carrier transport properties of CGA, which greatly enhanced the activity of the photocatalytic reaction and also showed high efficiency in removing other types of organic pollutants. Radical trapping experiments further confirmed that the superoxide anion (·O2−) is the main active species in the photocatalytic process. In addition, the monolithic aerogel has good recyclability and mechanical stability. This study not only demonstrates the great potential of ZCGA in the field of photocatalysis but also provides new ideas for designing efficient, recyclable, and visible light-responsive photocatalysts.

Fabrication of double S-scheme Sr2MgSi2O7:Eu2+,Dy3+/ZnIn2S4/UiO-66-NH2 heterojunctions with photon storage effect for enhanced round-the-clock photocatalysis

Persistent light-emitting materials (PLMs), which have the potential to store and release light energy after light irradiation, are receiving increasing attention for their role in prolonging the lifetime of photogenerated electrons for the development of photocatalysts with round-the-clock applications. In this paper, a double S-scheme Sr2MgSi2O7:Eu2+,Dy3+/ZnIn2S4/UiO-66-NH2 (SZU) heterojunction with round-the-clock catalytic activity was prepared by hydrothermal self-assembly method. The photocatalytic performance of the SZU heterojunction for RhB(MB) degradation was significantly improved compared with the pristine ZnIn2S4 and UiO-66-NH2. The SZU heterojunction has excellent catalytic degradation performance for RhB (MB), and the removal rate of RhB (MB) reaches 72.2 % (81.7 %) after visible light irradiation for 40 (60) minutes. After the end of light, the total removal rate of RhB (MB) reached 86.7 % (96.8 %) when the catalysis continued for several hours under dark conditions, which was 14 % and 15 % higher than that under visible light irradiation, respectively. Based on the characteristics of SMS photoluminescence, combined with a large number of photocatalytic experiments, The sustained photocatalytic activity was enhanced under both daytime and darkness conditions, not only because of the production of SZU complexes, which prolonged the visible light response of ZnIn2S4, but also because of the construction of double S-scheme heterojunctions, which facilitates the light storage capacity, charge transfer, and the separation of photo-induced charge carriers and effectively promoted the photocatalytic activity of the photocatalysts. This work contributes to a deeper understanding of the design of round-the-clock photocatalysts, and provides a useful exploration for the practical application of photocatalytic technology.

N-coordinated iron sites dispersed in porous carbon frameworks to activate peroxymonosulfate for efficient sulfisoxazole degradation and real hospital wastewater decontamination

Herein, an N-coordinated Fe site dispersed in porous carbon frameworks (Fe-NC) fabricated from zeolitic imidazolate frameworks encapsulated with iron acetylacetonate (Fe(acac)3 @ZIFs) was employed to activate peroxymonosulfate (PMS) for the attenuation of sulfisoxazole (SIZ) and treating real hospital wastewater. The constructed Fe-NC/PMS system exhibited good catalytic stability for SIZ degradation, maintaining excellent degradation performance over multiple cycles with virtually no leaching. The quenching experiments, electron paramagnetic resonance (EPR) capture analyses, and semi-quantitative measurements showed that singlet oxygen (1O2) and high-valent metal-oxo species were mainly responsible for SIZ degradation by Fe-NC/PMS. Significantly, ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS) was used to trace 134 pharmaceutical contaminants in real hospital wastewater. Effective degradation was achieved for 87 % of the pharmaceutical contaminants by the Fe-NC/PMS process. Seventy-four pharmaceutical contaminants were eliminated. Taken together, this work successfully established the Fe-NC/PMS technology using the developed iron-based materials and explored its application to real hospital wastewater treatment, providing an eco-friendly and effective strategy for treating wastewater.

Efficient degradation of methylene blue and HCHO by nonmetallic B-doped g-C3N5: activity and mechanism analysis

To solve the pollution of natural water bodies by organic dyes and the exceeding of indoor HCHO standards caused by renovation, the study realized the band gap modulation of g-C3N5, a novel semiconductor photocatalytic material, by using H3BO3 as a source of nonmetallic B. The prepared B/g-C3N5 has shown excellent photocatalytic performance and stability for organic dye degradation in water bodies and indoor HCHO removal. The degradation rate of methylene blue (MB) reached 95% in 60 min of visible light, and the removal rate of HCHO reached 96.3% in 180 min of visible light. The MB and HCHO were efficiently degraded to small molecule inorganic compounds such as CO2 and H2O under the oxidation of active groups such as ·O2 − and h+. The doping of nonmetallic B realizes the efficient separation of e−-h+ of g-C3N5, improve the absorption performance of visible light, and broaden the spectral range significantly. The modulation of the g-C3N5 band gap provides a potential application scenario for the development of novel photocatalytic materials.

Visible-light-response Fe-doped BiOCl microspheres with efficient photocatalysis-Fenton degradation of antibiotics

The combination of photocatalysis and Fenton reaction has been considered as a promising technology for the removal of antibiotics from wastewater. In this study, the Fe-doped BiOCl was synthesized by solvothermal method for photocatalysis-Fenton degradation of levofloxacin (LEV). Fe/BiOCl exhibited a flower-like microsphere structure with the lattice doping of Fe3+ in BiOCl. Under the synergistic of visible light irradiation and H2O2, the excellent degradation performance of Fe/BiOCl towards LEV was achieved (97.8 %) after 100-min reaction at Fe-doping content of 5 % and H2O2 addition of 3 mM. The Fe deposition extended the light absorption range and reduced the recombination of photogenerated carriers. The photogenerated electrons could accelerate the cycling of Fe2+/Fe3+, and improve the utilization efficiency of H2O2. The hydroxyl radical (OH), superoxide radical (O2−) and holes (h+) played crucial roles during the photocatalysis-Fenton degradation of LEV. The present study provided valuable insights into the development of photocatalysis-Fenton synergy system for the effective decontamination of antibiotic wastewater.

Promoting Electricity Production and Cr (VI) Removal Using a Light–Rutile–Biochar Cathode for Microbial Fuel Cells

Microbial fuel cell (MFC) technology holds significant promise for the production of clean energy and treatment of pollutants. Nevertheless, challenges such as low power generation efficiency and the high cost of electrode materials have impeded its widespread adoption. The porous microstructure of biochar and the exceptional photocatalytic properties of rutile endow it with promising catalytic potential. In this investigation, we synthesized a novel Rutile–Biochar (Rut-Bio) composite material using biochar as a carrier and natural rutile, and explored its effectiveness as a cathode catalyst to enhance the power generation efficiency of MFCs, as well as its application in remediating heavy metal pollution. Furthermore, the impact of visible light conditions on its performance enhancement was explored. The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) analysis validated the successful fabrication of rutile composites loaded with biochar. The maximum current density and power density achieved by the MFCs were 153.9 mA/m2 and 10.44 mW/m2, respectively, representing a substantial increase of 113.5% and 225% compared to the control group. In addition, biochar-supported rutile MFCs showed excellent degradation performance of heavy metal pollutants under light conditions. Within 7 h, the Cr6+ degradation rate reached 95%. In contrast to the blank control group, the removal efficiency of pollutants exhibited increases of 630.8%. The cyclic degradation experiments also showcased the remarkable stability of the system over multiple cycles. This study successfully integrated natural rutile and biochar to fabricate highly efficient cathode photocatalyst composites, which not only enhanced the power generation performance of MFCs but also presented an environmentally sustainable and economically viable method for addressing heavy metal pollution.

Synthesis of Silver(I) Complexes through In Situ Reactions of dppeda with dmp in the Presence of Silver Halides for Photocatalysis.

Due to the unique photosensitivity of silver compounds, they exhibit good photocatalytic activity as photocatalysts in the degradation of water pollutants. However, silver compounds have poor cycling stability and are prone to decomposition and reaction under light to form metallic silver, which greatly limits their practical application. Herein, a (2-(2-(diphenylphosphaneyl)ethyl)-9-methyl-1.10-phenanthroline (PSNNP)) pincer ligand was designed for stabilizing the central metal. The in situ-formed PSNNP ligand could be readily generated in one pot with the participation of silver halides. The reaction of silver halides with dppeda (N,N,N',N'-tetra(diphenylphosphanylmethyl)ethylene diamine) in the presence of dmp (2,9-dimethyl-1,10-phenanthroline) in acetonitrile afforded complexes Ag2X2 (PSNNP)2 (complexes 1, 2) (X = Cl, Br). Single-crystal X-ray diffraction shows that the tridentate coordination of the pincer ligand provides strong binding with metal centers and leads to high stability of the pincer metal unit. The removal rate of rhodamine B (RhB) by complexes 1 and 2 can reach up to 100%, demonstrating an excellent photocatalytic degradation performance for organic dyes. The important effect of PSNNP ligands on photocatalytic properties after coordination with central metals was studied through experiments and discrete Fourier transform (DFT) calculations. The photocatalytic reaction mechanism of complexes 1 and 2 was also studied. This result provides an effective pathway for the first synthesis of PSNNP and interesting insights into photocatalytic degradation chemistry.

An innovative functional compatibility strategy for poly (lactic acid) and polypropylene carbonate blends to achieve superior toughness, degradability, and optical properties

This study, for the first time, unveils the potential of dibutyl itaconate (DBI) in enhancing the compatibility between PLA (poly (lactic acid)) and PPC (polypropylene carbonate), systematically investigating the effects of DBI amount on the thermal, optical, rheological, mechanical, and degradation properties and microstructure of the PLA/PPC/DBI blends. The results showed that DBI could chemically react with PLA and PPC, forming a PLA-co-DBI-co-PPC copolymer structure, thereby improving the compatibility between PLA and PPC. When the DBI amount reached 8 wt%, only one Tg was observed in the blend system, and no distinct phase interface was visible in the fracture surface of the blend specimens. This indicated that at this DBI amount, the PLA and PPC had transitioned from a partially compatible system to a fully compatible system. With the increase in DBI amount in the system, the elongation at break and notched impact strength of the blends initially increased and then decreased, while the storage modulus, loss modulus, and complex viscosity showed a gradual downward trend. When the DBI amount increased to 10 wt%, the flexibility of the blends reached its peak, with the values rising to 494.7 % and 8494.1 J/m2, respectively, representing 13.7 times and 2.5 times those of the neat PLA/PPC blends. At this point, the impact specimens exhibited significant plastic flow in the direction of force, showing distinct ductile fracture characteristics. Meanwhile, the degradation performance of the PLA/PPC blends increased with the addition of DBI. The introduction of DBI effectively facilitated the penetration of water molecules into the PLA/PPC molecular chains, enhancing the hydrolysis of ester bonds, leading to a maximum mass loss rate of 84.1 %, which was significantly higher than the 20.3 % of the neat PLA/PPC blends. In addition, the addition of DBI significantly reduced the haze of the blends while maintaining high light transmittance, demonstrating excellent optical properties (light transmittance remained above 92.4 %, and haze decreased from 37.1 % to 11.1 %). In conclusion, this study provides a new approach for the development of high-performance PLA-based biodegradable composites. The resulting blends exhibit excellent toughness, degradation performance, and optical properties, significantly enhancing their application potential in fields such as disposable products, packaging, agriculture, and 3D printing materials.

Poly(butylene 2,5-thiophenedicarboxylate-co-glycolate) copolyesters with good degradation and barrier properties

In this work, poly(butylene 2,5-thiophenedicarboxylate-co-glycolate) (PBTFGA) copolyesters were synthesized from 2,5-thiophenedicarboxylic acid, 1,4-butanediol and glycolic acid. The influence of the glycolic acid content on thermal properties, mechanical properties and degradation capacity of copolyesters was systematically investigated. The glass transition temperature of copolyesters closely matched that of poly(butylene 2,5-thiophenedicarboxylate) (PBTF). While also demonstrating good thermal stability. When the glycolic acid content was low, the copolyesters exhibited some crystallization capability, but they gradually became fully amorphous as the glycolic acid content increased. The tensile tests revealed that the young's modulus of the PBTFGA copolyesters ranged from 69.2 MPa to 221.4 MPa. With elongation at break exceeding 659%, outperforming most biodegradable packaging materials. Copolyesters exhibited excellent gas barrier properties to both oxygen (PO2 = 0.024 barrer) and carbon dioxide (PCO2 = 0.029 barrer), both of which are superior to poly(butylene 2,5-thiophenedicarboxylate). The incorporation of glycolic acid significantly reduced the crystalline content of the copolyesters, facilitating the interaction of water molecules with ester bonds in the polymer backbone. The weight of poly(butylene 2,5-thiophenedicarboxylate-co-glycolate) was decreased significantly during enzymatic hydrolysis, indicating excellent degradation performance

Three-dimensional gel network structure of agarose interlayer dispersed Pd nanoparticles in copper foam electrode for electrocatalytic degradation of doxycycline hydrochloride

In this study, we successfully prepared palladium/agarose/copper foam (Pd/AG/CF) composite electrodes by utilizing the three-dimensional network structure agarose (AG), a green material derived from biomass, and homogeneously immobilizing palladium (Pd) atoms on a copper foam (CF) substrate through a facile route. The electrode showed excellent performance in the electrocatalytic degradation of doxycycline (DOX), with a high DOX degradation rate of 92.19 % in 60 min. In-depth studies revealed that palladium can form metal-metal interactions with the CF substrates, which enhances the electron transfer on the catalyst surface. In addition, the introduction of agarose effectively prevented the agglomeration of palladium nanoparticles. In addition, the hydroxyl functional groups in the molecular structure of agarose facilitate interactions between water molecules and the electrode interface through the formation of hydrogen bonds, thereby further enhancing the efficiency of the electrocatalytic reaction. In addition to good stability and reusability. Microbial toxicity test results show that the degraded wastewater has minimal impact on the environment. Also, possible degradation pathways of DOX were explored in this study. Finally, a novel continuous flow reactor was designed, featuring a unique design that ensures full contact between wastewater and the composite electrodes, thereby achieving continuous and efficient treatment of antibiotic wastewater.

Potential application of SDSO-layered double hydroxide in wastewater treatment: Synergy between hydrophobicity and activation activity

The hydrophobic surface properties of catalysts, generally overlooked in the field of sulfate radical-based advanced oxidation processes (SR-AOPs), have significant potential in enhancing the applicability of catalysts in realistic wastewater treatment. The conflicting nature of hydrophobicity and activation activity presents considerable challenges in developing heterogeneous oxidation. To overcome such limitation, herein, different surfactants were employed to regulate the surface properties of CoCu-layered double hydroxides (LDH) for the activation of peroxymonosulfate (PMS). Our results demonstrated that by comparison with sodium dodecyl sulfate (SDS) and sodium laurate (SLA), sodium dodecyl sulfonate (SDSO) regulated LDH (SDSO-LDH) exhibited the most effective interpolation of organic anions into the interlayer space, simultaneously showing efficient ability for PMS activation and hydrophobicity. The SDSO-LDH/PMS system exhibited excellent degradation performance of various emerging contaminants (ECs), with Co(IV) = O and SO4•- species identified as the dominant oxidative intermediates. Density functional theory (DFT) calculations further confirmed the thermodynamic feasibility of these reactions. Moreover, the effective degradation of intrinsic organic substances in realistic wastewater and sustained hydrophobicity establishes SDSO-LDH a competitive candidate catalyst for SR-AOPs. The synergy between activation activity and hydrophobicity offers a novel perspective for the application of SR-AOPs in wastewater treatment.

Integration of Silver Nanoparticles into Carbon-Encapsulated Tungsten Oxide Promoting Visible-Light-Driven Photocatalytic Degradation Efficiency

WO3-based photocatalysts have garnered popularity due to their low cost and high stability. However, the strong photogenerated electron-hole recombination limits their practical applicability. Herein, we developed an innovative heterostructure that integrates silver nanoparticles (Ag NPs) into carbon-encapsulated WO3 (C-WO3) through a combination of solvothermal synthesis and photoreduction methods. Under visible light irradiation, the Ag/C-WO3 photocatalyst demonstrated significant photocatalytic activity for rhodamine B (RhB) degradation, and the fine-tuned Ag/C-WO3 photocatalyst possesses excellent RhB degradation performance, achieving a removal rate of 98.2 % with excellent photostability. The photocatalytic process follows first-order kinetics, with adsorbent diffusion identified as the rate-limiting step. The optimized Ag/C-WO3 had an apparent rate constant of 0.039 min−1, 9.75 times higher than that of the unmodified C-WO3 (0.004 min−1). The enhanced photocatalytic activity is primarily owing to the surface plasmon resonance effect of Ag NP, which increases the absorption of visible light and boosts electron generation. Additionally, the carbon layer that encapsulates WO3 serves as a bridge for electron transfer from Ag to WO3, thereby accelerating the separation of photogenerated electron-hole pairs and elevating the overall photocatalytic degradation efficiency. The Ag NP-decorated C-WO3 with superior degradation properties is expected to be a potential candidate in practical and industrial applications.

Perfluorooctanoic acid efficient chain reaction degradation in multifunctional iron-sulfur mineral augmentation geobiochemical remediation system

Serious contamination of perfluorooctanoic acid (PFOA) has aroused global concern. General biotransformation or iron-based materials did not meet efficient PFOA elimination. Here, specific green and low-carbon microorganism-biochar pellets, multi-component and multifunctional iron-sulfur (FexSy) mineral pellets, and a microbe-FexSy interaction device were developed to solve this problem. The multi-scale (molecular, interface, and column scales) research method combined with the multi-process reaction model was constructed to explore PFOA removal mechanism. Results revealed that microbe-FexSy interaction achieved excellent PFOA degradation performance and retention effect, with degradation rate λ (0.213 h−1) increased by 113 % than FexSy (0.100 h−1) device. The distribution coefficient Kd and kinetic adsorption α increased by 18.54 % and 22.61 %; the fraction of kinetic sorption increased by 63.83 % in microbe-FexSy device (77 %) than alone FexSy (47 %) device. Delftia and Pseudomonas combined with Fe2+ drove an efficient cycle chain reaction for PFOA. Quantitative structure–activity relationship (QSAR) model prediction results indicated that intermediates exhibited lower biotoxicity than PFOA. Furthermore, NO3– further increased the retention effect of microbe-FexSy device for PFOA with little reaction rate fluctuation, making it promising for eliminating PFOA contamination, especially in NO3– type of groundwater. It provided an efficient technology and device based on microbe-mineral interaction in remediating PFOA-contaminated groundwater.