Degradation Rate Research Articles

Nanostructured Mn@NiO composite for addressing multi-pollutant challenges in petroleum-contaminated water

Efficient catalysts play a pivotal role in advancing eco-friendly water treatment strategies, particularly in the removal of diverse organic contaminants found in water-petroleum sources. This study addresses the multifaceted challenges posed by contaminants, encompassing a spectrum of heavy metals such as As, Cd, Cr, Mn, Mo, Ni, Pb, Sb, Se, and Zn alongside pollutants like oily water (OIW), total suspended solids (TSS), chemical oxygen demand (COD), dyes, and pharmaceuticals, posing threats to both aquatic and terrestrial ecosystems. Herein, we present the synthesis of biogenically derived Mn@NiO nanocomposite (NC) photocatalysts, a sustainable methodology employing an aqueous Rosmarinus officinalis L. extract, yielding particles with a size of 36.7 nm. The catalyst demonstrates exceptional efficacy in removing heavy metals, achieving rates exceeding 99–100% within 30 min, alongside notable removal efficiencies for OIW (98%), TSS (87%), and COD (98%). Furthermore, our photodegradation experiments showed remarkable efficiencies, with 94% degradation for Rose Bengal (RB) and 96% for methylene blue (MB) within 120 min. The degradation kinetics adhere to pseudo-first-order behavior, with rate constants of 0.0227 min−1 for RB and 0.0370 min−1 for MB. Additionally, the NC exhibits significant antibiotic degradation rates of 97% for cephalexin (CEX) and 96% for amoxicillin (AMOX). The enhanced photocatalytic performance is attributed to the synergistic interplay between the Mn and NiO nanostructures, augmenting responsiveness to sunlight while mitigating electron-hole pair recombination. Notably, the catalyst demonstrates outstanding stability and reusability across multiple cycles, maintaining its stable nanostructure without compromise.Graphical

Optimizing the Synergistic Effect of Co and Fe for Efficient and Durable Oxygen Evolution under Alkaline Conditions.

Developing robust oxygen evolution reaction (OER) electrocatalysts is crucial for advancing anion exchange membrane water electrolysis (AEMWE). In this study, we present a catalyst optimizing the synergistic effect of Co and Fe by creating a CoFe-based layer on a Fe-based electrode (Fe@CoFe). The Fe@CoFe exhibits an overpotential of 168 mV at 10 mA cm-2 under half-cell conditions and a current density of 10 A cm-2 at 2 V in the AEMWE system with 1 M KOH. Moreover, it showcases a degradation rate of 76 μV h-1 for 2000 h at 500 mA cm-2 in the single-cell system. This study demonstrates the feasibility of achieving efficient and durable water electrolysis using a transition metal-based catalyst exclusively fabricated via electrodeposition.

A robust and biodegradable hydroxyapatite/poly(lactide-co-ε-caprolactone) electrospun membrane for dura repair.

Typically occurring after trauma or neurosurgery treatments, dura mater defect and the ensuing cerebrospinal fluid (CSF) leakage could lead to a number of serious complications and even patient's death. Although numerous natural and synthetic dura mater substitutes have been reported, none of them have been able to fulfill the essential properties, such as anti-adhesion, leakage blockage, and pro-dura rebuilding. In this study, we devised and prepared a series of robust and biodegradable hydroxyapatite/poly(lactide-co-ε-caprolactone) (nHA/PLCL) membranes for dura repair via an electrospinning technique. In particular, PLLA/PCL (80/20) was selected for electrospinning due to its mechanical properties that most closely resembled natural dural tissue. Studies by SEM, XRD, water contact angle and in vitro degradation showed that the introduction of nHA would destroy PLCL's crystalline structure, which would further affect the mechanical properties of the nHA/PLCL membranes. When the amount of nHA added increased, so did the wettability and in vitro degradation rate, which accelerated the release of nHA. In addition, the high biocompatibility of nHA/PLCL membranes was demonstrated by in vitro cytotoxicity data. The in vivo rabbit dura repair model results showed that nHA/PLCL membranes provided a strong physical barrier to stop tissue adhesion at dura defects. Meanwhile, the nHA/PLCL and commercial group's CSF had a significantly lower number of inflammatory cells than the control groups, validating the nHA/PLCL's ability to effectively lower the risk of intracranial infection. Findings from H&E and Masson-trichrome staining verified that the nHA/PLCL electrospun membrane was more favorable for fostering dural defect repair and skull regeneration. Moreover, the relative molecular weight of PLCL declined dramatically after 3 months of implantation, according to the results of the in vivo degradation test, but it retained the fiber network structure and promoted tissue growth, demonstrating the good stability of the nHA/PLCL membranes. Collectively, the nHA/PLCL electrospun membrane presents itself as a viable option for dura repair.

Anthraquinone and its Derivatives as a Recyclable Photocatalyst for Efficient Photocatalytic Degradation of Rhodamine B in Water under Visible Light

AbstractThis study presents findings that suggest it is possible to fine‐tune and enhance the optical properties of anthraquinone (AQ) and its photocatalytic performance in the degradation of rhodamine B (RhB) at the molecular level through varying its keleton substituents. Specifically, the electron‐withdrawing substituent demonstrates a more pronounced improvement effect compared to the electron‐donating substituent. Out of the several compounds, 2‐carboxyanthraquinone (AQ−COOH) exhibits the highest photocatalytic activity. This is due to its ionization in water, generating H+ ions that enhance the destruction of RhB through photodegradation. After 30 min of exposure to visible light, the degradation rate of RhB reaches an impressive 99.9 %. It is noteworthy that a hydrochloric acid solution with a concentration of 0.5 mmol ⋅ L−1 has a considerable promoting impact on the photodegradation of RhB catalyzed by AQ−COOH, and that the total degradation of RhB can be accomplished in 15 min. In addition, AQ−COOH also has good applicability for the degradation of tetracycline, methylene blue, and methyl orange. As a recyclable solid catalyst, the catalytic activity of AQ−COOH remained mostly unchanged after being used five times. Additionally, AQ−COOH did not undergo degradation when exposed to visible light, indicating its excellent stability in the process of catalyzing RhB degradation. According to quenching experiments and EPR spectrum characterizations, the photo‐generated active species oxygen vacancies (h+), photogenerated electrons (e−), superoxide free radicals (O2⋅−), singlet oxygen (1O2) and hydroxyl radical (•OH) are involved in the hypothesized photo‐catalytic degradation mechanism.

Compare clinical efficacy and safety of neoadjuvant therapy and neoadjuvant chemoradiotherapy for locally advanced rectal cancer: Meta-analysis.

To compare the efficacy and safety of total neoadjuvant therapy (TNT) and neoadjuvant chemoradiotherapy (nCRT) in the treatment of middle and low locally advanced rectal cancer. Our study will systematically collect and integrate studies to evaluate the ability of these two treatments to improve tumor shrinkage rates, surgical resection rates, tumor-free survival, and severe adverse events. To provide clinicians and patients with more reliable treatment options to optimize treatment outcomes and quality of life for patients with locally advanced rectal cancer by comparing the advantages and disadvantages of the two treatment options. A full search of all clinical studies on the effectiveness and safety of TNT and nCRT for treating locally advanced rectal cancer identified in Chinese (CNKI, Wanfang, China Biomedical Literature Database) and English (PubMed, Embase) databases was performed. Two system assessors independently screened the studies according to the inclusion and exclusion criteria. Quality evaluation and data extraction were performed for the included literature. We used RevMan 5.3 software to perform a meta-analysis of the pathologic complete response (pCR) rate, T stage degradation rate, resection 0 (R0) rate, anal grade 3/4 acute toxicity rate, perioperative complications, overall survival (OS), and disease-free survival (DFS) in the TNT and nCRT groups. Finally, 14 studies were included, six of which were randomized controlled studies. A total of 3797 patients were included, including 1865 in the TNT group and 1932 in the nCRT group. The two sets of baseline data were comparable. The results of the meta-analysis showed that the pCR rate [odds ratio (OR) = 1.57, 95% confidence interval (CI): 1.30-1.90, P < 0.00001], T stage degradation rate (OR = 2.16, 95%CI: 1.63-2.57, P < 0.00001), and R0 resection rate (OR = 1.42, 95%CI: 1.09-1.85, P = 0.009) were significantly greater in the nCRT group than in the nCRT group. There was no significant difference in the incidence of grade 3/4 acute toxicity or perioperative complications between the two groups. The 5-year OS [hazard ratio (HR) = 0.84, 95%CI: 0.69-1.02, P = 0.08] and DFS (HR = 0.94, 95%CI: 0.03-1.39, P = 0.74) of the TNT group were similar to those of the nCRT group. TNT has greater clinical efficacy and safety than nCRT in the treatment of locally advanced rectal cancer.

The Effect of Natural Plant and Animal Fibres on PLA Composites Degradation Process

One of the methods to reduce long-term excessive plastic waste is the development and use of composite materials based on biodegradable polymers and natural fibres. Composites with natural fibres can exhibit very good mechanical properties, and the presence of natural fibres can significantly accelerate the degradation of the material. This study aimed to manufacture and analyse the biodegradation process of composites based on biodegradable polylactide (PLA) filled with flax and sheep wool fibres. The effect of flax and wool fibres and their content on the degradation rate compared to that of pure PLA was investigated. The degradation progress and properties of the composites were studied using an optical microscope, SEM, measurement of surface roughness, and contact angle. Additionally, flexural strength tests, a dynamic mechanical analysis (DMA), and a thermogravimetric analysis (TGA) were conducted. The effect of natural fibres on the phase transition and degree of crystallinity was analysed using differential scanning calorimetry (DSC). The results showed that PLA degrades only under UV light, but not in the composter simulating the natural environment. However, the incorporation of both types of fibres accelerated degradation of PLA/fibres composites in soil. Flax fibre composites exhibited better mechanical properties than pure PLA. For composites with wool fibres, although they showed a significant acceleration of the degradation process in the soil, their large content in the composite caused a reduction of mechanical properties. This research showed the positive effect of the addition of natural fibres on the biodegradation of PLA.

The Effect of Natural Plant and Animal Fibres on PLA Composites Degradation Process

One of the methods to reduce long-term excessive plastic waste is the development and use of composite materials based on biodegradable polymers and natural fibres. Composites with natural fibres can exhibit very good mechanical properties, and the presence of natural fibres can significantly accelerate the degradation of the material. This study aimed to manufacture and analyse the biodegradation process of composites based on biodegradable polylactide (PLA) filled with flax and sheep wool fibres. The effect of flax and wool fibres and their content on the degradation rate compared to that of pure PLA was investigated. The degradation progress and properties of the composites were studied using an optical microscope, SEM, measurement of surface roughness, and contact angle. Additionally, flexural strength tests, a dynamic mechanical analysis (DMA), and a thermogravimetric analysis (TGA) were conducted. The effect of natural fibres on the phase transition and degree of crystallinity was analysed using differential scanning calorimetry (DSC). The results showed that PLA degrades only under UV light, but not in the composter simulating the natural environment. However, the incorporation of both types of fibres accelerated degradation of PLA/fibres composites in soil. Flax fibre composites exhibited better mechanical properties than pure PLA. For composites with wool fibres, although they showed a significant acceleration of the degradation process in the soil, their large content in the composite caused a reduction of mechanical properties. This research showed the positive effect of the addition of natural fibres on the biodegradation of PLA.

Co‐Substrate and Phosphate Buffer Enhanced Atrazine Degradation and Electricity Generation in a Bioelectrochemical System

ABSTRACTRefractory organic pollutant removal can be enhanced by a bioelectrochemical system via the addition of electron donors/acceptors. In this study, a single‐chamber soil microbial fuel cell (MFC) was constructed, and electricity production and atrazine removal efficiency were assessed using different co‐substrates and phosphate buffer concentrations. The co‐substrates compensated for the lack of soil organic matter and provided a sufficient carbon source for microorganisms to facilitate MFC electricity generation and efficient atrazine removal. The maximum voltage (94 mV), power density (39.41 mW m−2), removal efficiency (85.30%), and degradation rate (1.68 mg kg−1 d−1) were highest in the soil MFCs with sodium acetate when compared with the other groups. Phosphate buffer significantly alleviated the dramatic soil pH change. The electricity generation and atrazine removal efficiency increased with the buffer concentration (0–0.10 g L−1). The maximum voltage (144 mV) and power density (89.35 mW m−2) were highest, total internal resistance (652 Ω) was lowest, and atrazine removal efficiency (90.95%) and degradation rate (1.54 mg kg−1 d−1) were determined in the soil MFCs with the phosphate buffer concentration of 0.10 g L−1, and. These results indicate that the co‐substrate and phosphate buffer can enhance the electricity generation of soil MFCs and atrazine removal.

&lt;span&gt;&lt;strong&gt;Enhanced thiamethoxam degradation in water&amp;nbsp; and soil by &lt;/strong&gt;&lt;em&gt;Phanerochaete &lt;/em&gt;&lt;strong&gt;sp. Th1 and &lt;/strong&gt;&lt;em&gt;Ensifer &lt;/em&gt;&lt;strong&gt;sp. Th2&lt;/strong&gt;&lt;/span&gt;

Thiamethoxam is widely applied to control pest insects, but it causes serious environmental contamination. In this study, the degradation processes of the compound in soil and water collected from a rice field by native microorganisms, by mixed culture of Phanerochaete sp. Th1 and Ensifer sp. Th2, and by both the mixed pure culture and native microorganisms were conducted. The result showed that the mixed culture inoculation increased thiamethoxam in all media. In liquid media, the degradation percentage of the substrate in collected water was 21.8±4.4%, collected water + inoculation was 44.2±5.0%, and mineral medium + inoculation was 98.0±0.4%. Degradation determination in media with 70% collected water and 30% dry soil showed that the main degradation occurred in the liquid phase. The degradation rates in the media with 50% collected water and 50% dry soil were higher in the surface layer, and lower in the bottom. Indigenous microorganisms also played an important role in the degradation process. This study provided valuable information on the thiamethoxam degradation in simulated media of a rice field and the role of Phanerochaete sp. Th1 and Ensifer sp. Th2 to enhance the degradation.

Smart manufacturing of ZIF-8 photonic crystals: Catalytic formaldehyde degradation and colorful eco-friendly coatings

Formaldehyde and other harmful gases cause environmental pollution and threaten human health. Environment-friendly coatings is an effective strategy to address these environmental and health concerns. In this study, a large-scale amorphous photonic crystals (APC) based on modified ZIF-8 (Hxh-ZIF-8) with photocatalytic degradation of formaldehyde and tunable structural color were designed for eco-friendly coatings by programmable smart manufacturing. As APC unit, Hxh-ZIF-8 nanoparticles with controllable diameters were synthesized utilizing solvothermal method and the −N = C = O group was introduced with thermal oxidation. The results of photocatalytic degradation revealed that H5h-ZIF-8, through thermal oxidation, exhibited a formaldehyde degradation rate 9.8 times than that of ZIF-8. The main reactive components in photocatalysis were holes (h+) and superoxide radicals (·O2–), showcasing both stability and reproducibility. The color and brightness of the APC were adjusted by tuning the Hxh-ZIF-8 diameter. The angle-independent APC ranging from red to purple were fabricated with 177, 165 and 235 nm Hxh-ZIF-8 nanoparticles in various proportions with programmable smart manufacturing. In this study, a large-scale ZIF-8-based APC was designed with programmable smart manufacturing for environment-friendly coating, which combined environmental protection technology with structural color, and paved a new strategy for the development of multifunctional materials in air quality management.

Structural design and evaluation of bone remodeling effect of fracture internal fixation implants with time-varying stiffness

The stiffness of an ideal fracture internal fixation implant should have a time-varying performance, so that the fracture can generate reasonable mechanical stimulation at different healing stages, and biodegradable materials meet this performance. A topology optimization design method for composite structures of fracture internal fixation implants with time-varying stiffness is proposed, considering the time-dependent degradation process of materials. Using relative density and degradation residual rate to describe the distribution and degradation state of two materials with different degradation rates and elastic modulus, a coupled mathematical model of degradation simulation mechanical analysis was established. Biomaterial composite structures were designed based on variable density method to exhibit time-varying stiffness characteristics. Taking the bone plate used for the treatment of tibial fractures as an example, a composite structure bone plate with time-varying stiffness characteristics was designed using the proposed method. The optimization results showed that material 1 with high stiffness formed a columnar support structure, while material 2 with low stiffness was distributed at the degradation boundary and inside. Using a bone remodeling simulation model, the optimized bone plates were evaluated. After 11 months of remodeling, the average elastic modulus of callus using degradable time-varying stiffness plates, titanium alloy plates, and stainless steel plates were 8 634 MPa, 8 521 MPa, and 8 412 MPa, respectively, indicating that the use of degradable time-varying stiffness plates would result in better remodeling effects on the callus.

Membrane Permeability and Responsiveness Drive Performance: Linking Structural Features with the Antitumor Effectiveness of Doxorubicin-Loaded Stimuli-Triggered Polymersomes.

The permeability and responsiveness of polymer membranes are absolutely relevant in the design of polymersomes for cargo delivery. Accordingly, we herein correlate the structural features, permeability, and responsiveness of doxorubicin-loaded (DOX-loaded) nonresponsive and stimuli-responsive polymersomes with their in vitro and in vivo antitumor performance. Polymer vesicles were produced using amphiphilic block copolymers containing a hydrophilic poly[N-(2-hydroxypropyl)methacrylamide] (PHPMA) segment linked to poly[N-(4-isopropylphenylacetamide)ethyl methacrylate] (PPPhA, nonresponsive block), poly[4-(4,4,5,5-tetra-methyl-1,3,2-dioxaborolan-2-yl)benzyl methacrylate] [PbAPE, reactive oxygen species (ROS)-responsive block], or poly[2-(diisopropylamino)ethyl methacrylate] (PDPA, pH-responsive block). The PDPA-based polymersomes demonstrated outstanding biological performance with antitumor activity notably enhanced compared to their counterparts. We attribute this behavior to a fast-triggered DOX release in acidic tumor environments as induced by pH-responsive polymersome disassembly at pH < 6.8. Possibly, an insufficient ROS concentration in the selected tumor model attenuates the rate of ROS-responsive vesicle degradation, whereas the nonresponsive nature of the PPPhA block remarkably impacts the performance of such potential nanomedicines.

Hydrogel Encapsulation Techniques and Its Clinical Applications in Drug Delivery and Regenerative Medicine: A Systematic Review.

Hydrogel encapsulation is a promising carrier for cell and drug delivery due to its ability to protect the encapsulated entities from harsh physiological conditions and enhance their therapeutic efficacy and bioavailability. However, there is not yet consensus on the optimal hydrogel type, encapsulation method, and clinical application. Therefore, a systematic review of hydrogel encapsulation techniques and their potential for clinical application is needed to provide a comprehensive and up-to-date overview. In this systematic review, we searched electronic databases for articles published between 2008 and 2023 that described the encapsulation of cells or drug molecules within hydrogels. Herein, we identified 9 relevant studies that met the inclusion and exclusion criteria of our study. Our analysis revealed that the physicochemical properties of the hydrogel, such as its porosity, swelling behavior, and degradation rate, play a critical role in the encapsulation of cells or drug molecules. Furthermore, the encapsulation method, including physical, chemical, or biological methods, can affect the encapsulated entities' stability, bioavailability, and therapeutic efficacy. Challenges of hydrogel encapsulation include poor control over the release of encapsulated entities, limited shelf life, and potential immune responses. Future directions of hydrogel encapsulation include the development of novel hydrogel and encapsulation methods and the integration of hydrogel encapsulation with other technologies, such as 3D printing and gene editing. In conclusion, this review is useful for researchers, clinicians, and policymakers who are interested in this field of drug delivery and regenerative medicine that can serve as a guide for the future development of novel technologies that can be applied into clinical practice.

Biodegradation rate and build-up of plastics in soil: A theoretical approach

The ecological risk assessment of a product released into the environment is a complex process that takes into account both its ecotoxicity and the Predicted Environmental Concentration (PEC) in the environment. The latter depends on the use, transport, fate (i.e. persistence) of the product. This article describes a model to determine the Predicted Environmental Concentration (PEC) of a biodegradable mulch film taking into account its characteristics, the frequency of application of the mulch film, its degradation rate, and the density of the soil to which it is applied. The effect of temperature on biodegradation kinetics was also taken into account to estimate the biodegradation rate achievable at a given temperature based on data obtained in the laboratory under standard conditions. Using the same approach as for pharmacokinetics, the model can calculate the average mulch film concentration at steady state and the maximum concentration applied. The PEC values can be compared with the Predicted No-Effect Concentration (PNEC) derived from ecotoxicity studies to characterise the risk associated with use of mulch film. The model, if validated by comparison of the calculated PECs with the Measured Environmental Concentrations (MECs), determined by detection and quantification of biodegradable mulch film residues in soil, may provide a valuable tool for the ecological risk assessment of biodegradable mulch films.

Guided Bone Regeneration for the Treatment of Peri-Implantitis: Clinical Case Report

Periodontal disease is characterized as an inflammatory process that damages the periodontal lining and/or support tissues. Peri-implantitis is among the periodontal alterations, being caused by bacterial biofilm causing loss of underlying bone insertion, leading to modifications in its architecture that form intraosseous defects of various types. For the treatment of peri-implantitis there are non-surgical, surgical, resective, regenerative, combined techniques and the decision-making will depend on the degree of the bone defect. Therefore, guided bone regeneration (GBR) is an efficient and simple technique for bone augmentation, which is widely used to restructure bone defects that occur in the alveolar ridge and in the peri-implant region. Biomaterials are alternatives to be used in guided bone regeneration due to their excellent biocompatibility, osteoinductive properties, low degradation rate and their hydrophilicity, which collaborates with the absorption of blood cells and proteins that will help in osseointegration. Female, 58-year-old normosistemic patient, attended a private dental office complaining of pain, bad smell, bleeding and bad taste in the peri-implant region referring to element 25, on its distal face to the mesial face of the element tooth 26. After imaging exams, periodontal probing and the patient's past history, extraction of element 26 was performed, decontamination protocol of the implant surface of 25 through mechanical, chemical and physical means performing antimicrobial photodynamic therapy and finally, a guided bone regeneration was performed, using the allogeneic bone grafting technique associated with a polytetrafluoroethylene membrane in its expanded form (e-PTFE) for recovery of the bone defect and alveolar preservation. Thus, guided bone regeneration has shown high success rates and greater predictability when well indicated and performed, making it important for the maintenance of periodontal and peri-implant health.

Nutritional Evaluation of Milk Thistle Meal as a Protein Feedstuff for Diets of Dairy Cattle.

The objective of this work is to investigate the chemical and nutritional value of milk thistle meal (MTM) in order to improve it and to provide theoretical support for its application in dairy cattle production. MTM was assessed in comparison with seven conventional protein feed sources, namely, soybean meal (SBM), cottonseed meal (CS), canola meal (CN), palm kernel meal (PK), rice bran meal (RB), corn germ meal (CG), and sesame meal (SS). The chemical composition of these feedstuffs was assessed using wet chemical analysis, the Cornell Net Carbohydrate and Protein System was used to evaluate the carbohydrate and protein fractions, and the in situ nylon bag technique and the modified three-step in vitro method were used to assess the rumen degradation and intestinal digestibility. Additionally, Fourier transform infrared technology was used to determine the feedstuff protein spectral molecular structure and its amino acid profile was also assessed. The result showed that MTM acid detergent fiber, lignin, unavailable nitrogen, and non-degradable carbohydrate content were higher than those of the other feedstuffs. It had a 17% and 36% rumen effective degradation rate of neutral detergent fiber and dry matter, respectively, and had the lowest small intestinal rumen undegradable protein digestibility rate. It was low in leucine, histidine, arginine, and proline, but high in methionine. The total area of amide I and amide II in the protein secondary structure was similar to that of CN and CS, and the amide I and II ratio was not different from that of RB. To sum up, MTM has a poor carbohydrate composition and is high in fiber but, in comparison to most other protein feeds, has a higher crude protein rumen effective degradation rate, similar to that of SBM, and it is a good source of methionine, a limiting amino acid. Hence, its nutritional value can be further improved for application in dairy feeding through processes such as microbial or enzymatic fermentation.

Bird-nest inspired cellulose-based biofoam with excellent performance enabled by gas–liquid interface co-assembly and thermal welding for plastic replacement

Traditional plastic foam, typically derived from fossil fuel-based polymers that are resistant to natural degradation, faces environmental challenges. As an alternative, cellulose, a biodegradable polymer, shows promise in the production of eco-friendly foam. Nonetheless, its reliance on hydrogen bonding between fibers poses limitations for practical applications. Here, drawing inspiration from bird nest structures, a straightforward and scalable method (co-assembly and thermal welding) has been developed for creating cellulose-PLA biofoam. The resulting biofoam displays advantageous properties such as low density (12.9 ∼ 27.1 kg/m3), high compression strength (modulus of 12.1 MPa·cm3·g−1), good thermal stability, and water stability (maintaining structural integrity in water). Moreover, it exhibits exceptional degradation rates (significant degradation within 40 days) and recyclability. Thus, this biofoam holds promise as a sustainable alternative to standard plastic foams, mitigating “white pollution.”

Highly efficient catalytic reduction of organic dyes, Cr (VI) and 4‐nitrophenol, and photocatalytic degradation of MB by an inorganic–organic hybrid polyoxometalate

It is urgent to remove various pollutants from the water environment. Therefore, an inorganic–organic hybrid polyoxometalate (POM) [PMoVI6MoV2VIV8O44{Co(2,2′‐bipy)2(H2O)}4]‐[PMoVI4MoV4VIV8O44{Co(2,2′‐bipy)2(H2O)}2]·4H2O (PMoVCo) was fully characterized by XRD, XPS, FTIR, SEM, BET and zeta potential techniques, and applied for the catalytic reduction of hazardous methylene blue (MB), methyl orange (MO), rhodamine B (RhB), Cr (VI) and 4‐nitrophenol (4‐NP) in aqueous media over NaBH4 under mild condition. The removal ratios were 99.6% (MB, 2.5 min), 97.0% (MO, 3.0 min), 92.5% (RhB, 2.0 min), 89.2% (Cr (VI), 2.0 min) and 89.6% (4‐NP, 2.5 min), respectively. The pseudo‐first‐order rate constants of the reactions were 1.992 min−1 (MB), 0.810 min−1 (MO), 1.768 min−1 (RhB), 1.186 min−1 (Cr (VI)) and 0.934 min−1 (4‐NP), respectively. Additionally, PMoVCo exhibited satisfactory catalytic activity for the photo‐Fenton‐like degradation of MB at neutral pH under visible light irradiation with a degradation rate up to 99.9% in 480 min. The results of the recycling experiment prove that PMoVCo has high catalytic reusability. Moreover, the possible mechanisms of the catalytic reduction and degradation processes were proposed. The catalytic activities of PMoVCo are better than other inorganic–organic hybrid POMs. All the results of this study indicate that PMoVCo has the potential to be a satisfactory catalyst for wastewater remediation via reduction or photocatalytic degradation.

A comparative study of metal-sulphide/ZnO for visible-light-induced photocatalysis and the six-flux photon absorption model of an external lamp photoreactor

This study compares the photocatalytic performance of three metal-sulphide/ZnO nanocomposites (Ag2S/ZnO, FeS/ZnO and NiS/ZnO) for degrading tetracycline (TC) under visible light irradiation. The nanocomposites were synthesized using a novel one-pot solid-phase combustion method, analysed by various characterization techniques (XRD, SEM, TEM, BET, FTIR, PL, and UV–vis DRS). Photocatalytic tests revealed significantly higher efficiencies for Ag2S/ZnO (87.50 %), FeS/ZnO (80.53 %) and NiS/ZnO (77.27 %) nanocomposites exhibit much higher photocatalytic efficiency than pure ZnO (42.63 %). The improved performance is attributed to the reduced bandgap energy and suppressed electron-hole (e-/h+) recombination facilitated. This can also be attributed to the photocatalytic inhibition test which confirmed the holes (h+) as the main inhibitor and identified the superoxides (O2•−) radical as the main active specie responsible for the degradation. Additionally, this study innovatively applies the Six Flux radiation absorption-scattering models (SFM) to an external lamp photocatalytic reactor. This approach allows precise determination of reactor parameters and intrinsic reaction kinetics for TC degradation, independent of the radiation field. The TC degradation rate, calculated at 5.6 × 104EinL−1S−1 for every point in the reaction space, shows a half-order dependence on the local volumetric rate of photon absorption (LVRPA) of 142.3 W/m3, at a photon flux of 115.42 W/m2. These findings elucidate the mechanisms behind enhanced visible-light photocatalysis and demonstrate the innovative application of photon absorption and light-scattering models to optimize reactor design and efficiency. This work offers valuable insights for developing advanced photocatalytic systems with improved performance and practical applicability.

Nanoconfinement steers nonradical pathway transition in single atom fenton-like catalysis for improving oxidant utilization

The introduction of single-atom catalysts (SACs) into Fenton-like oxidation promises ultrafast water pollutant elimination, but the limited access to pollutants and oxidant by surface catalytic sites and the intensive oxidant consumption still severely restrict the decontamination performance. While nanoconfinement of SACs allows drastically enhanced decontamination reaction kinetics, the detailed regulatory mechanisms remain elusive. Here, we unveil that, apart from local enrichment of reactants, the catalytic pathway shift is also an important cause for the reactivity enhancement of nanoconfined SACs. The surface electronic structure of cobalt site is altered by confining it within the nanopores of mesostructured silica particles, which triggers a fundamental transition from singlet oxygen to electron transfer pathway for 4-chlorophenol oxidation. The changed pathway and accelerated interfacial mass transfer render the nanoconfined system up to 34.7-fold higher pollutant degradation rate and drastically raised peroxymonosulfate utilization efficiency (from 61.8% to 96.6%) relative to the unconfined control. It also demonstrates superior reactivity for the degradation of other electron-rich phenolic compounds, good environment robustness, and high stability for treating real lake water. Our findings deepen the knowledge of nanoconfined catalysis and may inspire innovations in low-carbon water purification technologies and other heterogeneous catalytic applications.