Activity For Degradation Research Articles

The N-acetylglucosaminyltransferase Radical fringe contributes to defects in JAG1-dependent turnover and signaling of NOTCH3 CADASIL mutants

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a genetic vascular dementia characterized by age-related degeneration of vascular mural cells and accumulation of a NOTCH3 mutant protein. NOTCH3 functions as a signaling receptor, activating downstream gene expression in response to ligands like JAG1 and DLL4, which regulate the development and survival of mural cells. This signal transduction process is thought to be connected with NOTCH3 endocytic degradation. However, the specific cellular circumstances that modulate turnover and signaling efficacy of NOTCH3 mutant protein remain largely unknown. Here, we found elevated NOTCH3 and Radical fringe (RFNG) expression in senescent human pericyte cells. We then investigated impacts of RFNG on glycosylation, degradation, and signal activity of three NOTCH3 CADASIL mutants (R90C, R141C, and C185R) in EGF-like repeat-2, 3, and 4, respectively. LC–MS/MS analysis showed that RFNG modified NOTCH3 WT and C185R to different degrees. Additionally, coculture experiments demonstrated that RFNG significantly promoted JAG1-dependent degradation of NOTCH3 WT but not that of R141C and C185R mutants. Furthermore, RFNG exhibited a greater inhibitory effect on JAG1-mediated activity of NOTCH3 R141C and C185R compared to that of NOTCH3 WT and R90C. In summary, our findings suggest that NOTCH3 R141C and C185R mutant proteins are relatively susceptible to accumulation and signaling impairment under cellular conditions of RFNG and JAG1 coexistence.

Involvement of sphingosine 1-phosphate signaling in insulin-like growth factor-II/mannose 6-phosphate receptor trafficking from endosome to the trans-Golgi network

The insulin-like growth factor II/mannose 6-phosphate (IGF-II/M6P) receptor is a multifunctional glycoprotein not only play roles in IGF-II degradation and pro-TGFβ activation but binding to and transport M6P-bearing lysosomal enzymes from the trans-Golgi network (TGN) or the cell surface to lysosomes. At present, information regarding a retrograde transport of IGF-II/M6P receptor from endosomes to the TGN is still limited. We show here that a continuous ligand-dependent activation of sphingosine 1-phosphate receptor type 3 (S1P3R) on the endosomal membranes is required for subsequent recycling back of cargo-unloaded IGF-II/M6P receptors to the TGN. We have further clarified that Gq coupled with S1P3R plays a critical role in the activation of casein kinase 2, which phosphorylates and keeps PACS1 connector protein active for the association with IGF-II/M6P receptors, which enables transport carrier formation with the aid of other adaptor proteins toward the TGN. These findings shed light on the molecular mechanism underlying how continuous activation of the S1P receptor and subsequent downstream Gq signaling regulates the retrograde transport of the empty IGF-II/M6P receptors back to the TGN.

Targeted aggregation of PETase towards surface of Stenotrophomonas pavanii for degradation of PET microplastics

Polyethylene terephthalate (PET) is one of the most widely used plastics, but its fragmentation into microplastics poses significant environmental challenges. The recycling of PET microplastics is hindered by their low solubility and widespread dispersion in the environment, making microbial in-situ degradation a promising solution. However, existing PET-degrading strains exhibited the limited effectiveness, primarily due to the diffusion of secreted hydrolases away from the PET surface. In this study, Stenotrophomonas pavanii JWG-G1 was engineered to achieve the targeted aggregation of PET hydrolase PETase on the cell surface by fusing it with an endogenous anchor protein. This approach aims to maximise the local concentration of PETase around PET, thereby increasing the overall rate of PET degradation. The PETase surface-aggregated system, S. pavanii/PaL-PETase, demonstrated the highest degradation efficiency, achieving 63.3 % degradation of low-crystallinity PET (lcPET) and 27.3 % degradation of high-crystallinity PET bottles (hcPET) at 30 °C. This represents the highest degradation rate reported for a displayed whole-cell system at ambient temperature. Furthermore, this system exhibited broad-spectrum degradation activity against various polyesters. These findings suggest that this system offers a promising, eco-friendly solution to PET and other polyester pollution, with potential implications for environmental bioremediation strategies.

Preparation of C@CuNi/TiO2 with a local surface plasmon resonance for photocatalytic degradation of organic dyes and antibiotics under visible light irradiation

A composite photocatalyst with carbon-coated CuNi nanoparticles-loaded TiO2 nanotubes (C@CuNi/TiO2) was synthesized via a microwave hydrothermal alkali stripping method combined with subsequent in-situ carbothermal reduction. The structure, morphology, and surface chemical composition were investigated using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The findings demonstrate that the microwave hydrothermal alkali peeling enables the formation of a three-dimensional C@CuNi/TiO2 composite structure. The results of transient photocurrent response (i-t) and electrochemical impedance spectroscopy under visible light demonstrate that C@CuNi/TiO2 exhibits a reduced rate of electron-hole recombination and lower surface resistance compared to C@TiO2, C@Cu/TiO2, and C@Ni/TiO2. After a two-hour exposure to visible light, the composite photocatalyst C@CuNi/TiO2, featuring a molar ratio of 2 % CuNi nanoparticles to TiO2 nanotubes, exhibited remarkable degradation activity towards organic dyes (Rhodamine B (RhB), Methylene Blue (MB), Methyl Orange (MO)), as well as antibiotics (tetracycline (TC) and levofloxacin (LVFX)). After 5 cycles of photocatalytic reaction, the photodegradation activity of RhB remained above 79 %. It is indicated that CuNi nanoparticles effectively trap and enrich photoelectrons through the photoexcitation of TiO2 nanotubes. Additionally, the local surface plasmonic resonance (LSPR) effect of CuNi nanoparticles reduces the recombination rate of photogenerated electron/hole and the electron transport resistance in the composite photocatalyst, thereby enhancing its overall photocatalytic activity.

CeO2 nanoparticle-modified BiOI nanoflowers as visible-light-driven heterojunction photocatalyst for tetracycline degradation and antibacterial

BiOI, a typical narrow-band gap visible-light-driven photocatalyst, possesses a high recombination rate of photogenerated electrons and holes, which hinders its practical application in environmental remediation. To improve its photocatalytic efficiency, BiOI/CeO2 heterojunction was designed and prepared via a facile chemical bath method. Compared to pure BiOI, the BiOI/CeO2 heterojunction not only enhanced the absorption of visible-light but also improved the separation and transfer efficiency of photogenerated carriers. Impressively, the BiOI/CeO2 heterojunction with a BiOI:CeO2 molar ratio of 2:1 (named CBOI-2) exhibited the best photocatalytic performance. The CBOI-2 heterojunction can degrade 80 % of tetracycline within 60 min, and the degradation activity was almost intact after three cycles. The reaction rate constant of CBOI-2 heterojunction was 22.1 times that of BiOI and 5.8 times that of CeO2. Moreover, CBOI-2 heterojunction behaves much better in antibacterial effect whose antibacterial efficiency reaches ∼99.6 %. A double charge-transfer mechanism was proposed in this work and it indicated that the improved photocatalytic efficiency mainly resulted from an enhanced separation and transfer of photogenerated carriers. During the photocatalytic reaction process, superoxide radicals, hydroxyl radicals and holes were generated, which play important roles in the degradation of tetracycline and antibacterial. This work provides important insights into the design of visible-light-driven photocatalysts with high photocatalytic activity for antibiotic degradation and bacteria killing.

Cobalt-doped graphitic carbon nitride: A multifunctional material for humidity sensing, electrochemical water splitting and environmental remediation applications

Graphitic carbon nitride (g-C3N4) has emerged as a promising eco-friendly material for catalysis and sensing applications due to their unique properties. However, limitations like low specific surface area, insufficient light absorption, and poor conductivity hinder their broader usability. Elemental doping has been established as an effective approach to modify the electronic structure and bandgap of g-C3N4 thus significantly expanding its light-responsive range for enhanced charge separation. This work reports on the fabrication of cost-effective and stable g-C3N4 and cobalt-doped g-C3N4 (Co@g-C3N4) via a simple one-step calcination process. The humidity sensing performance of both g-C3N4 and Co@g-C3N4 was evaluated across a broad humidity range (7 % - 94 % RH) at various testing frequencies. The results demonstrated good reversibility with Co@g-C3N4 exhibiting superior performance compared to pristine g-C3N4. Furthermore, the synthesized materials were assessed for their suitability as photoelectrochemical water splitting catalysts for hydrogen production, representing a step towards energy-efficient fuel cells. Notably, Co@g-C3N4 displayed enhanced performance with a lower onset potential (420 mV) and a lower Tafel slope (65.4 mV dec-1) for the hydrogen evolution reaction (HER) compared to undoped counterparts. Additionally, Co@g-C3N4 nanorods exhibited remarkable performance for the oxygen evolution reaction (OER), showcasing a lower onset potential (1.505 V) and a considerably low overpotential (270 mV), surpassing numerous reported electrocatalysts and even rivaling precious-metal-based ones. Finally, enhanced photocatalytic activities for organic dyes degradation were recorded for the mentioned materials. Therefore, g-C3N4 and related materials have great potential for their industrial electrochemcial applications.

Measuring quantity in ecosystem markets and ecosystem accounts

AbstractThe quantity of ecosystem services produced from land cannot be readily measured at the site level needed for participation in ecosystem markets, or at a regional level needed to create ecosystem accounts. This paper applies biological scaling principles to develop a quantity metric in which areas of ecosystem (extent) scale allometrically to ecosystem services (a capacity measure) according to a scaling exponent defined by the fractal dimension of ecosystem vegetation. A key conclusion of this paper is that the quantity of ecosystem services arising from ecosystem degradation and conservation activities cannot be estimated unless information about the space‐filling properties of vegetation is observed and included in the quantity measurement methodology. The paper demonstrates how remote sensing techniques can be applied to systematically measure ecosystem extent and fractal dimension. It illustrates the economic efficiency and environmental outcome implications of such a quantity metric through comparison with current quantity estimation methods that assume isometric scaling. The quantity metric proposed has potential applications to ecosystem accounting. It enables information currently reported in land accounts to be combined with information reported in ecosystem condition accounts to create ecosystem stock accounts measured in physical units.

Efficient generation of 1O2 by activating peroxymonosulfate on graphitic carbon nanoribbons for water remediation

Few-layer graphitic carbon nanoribbons (GCN) with rich defective sites were prepared by pyrolysis at 800 oC in N2 of in situ-chelated Fe-polyaniline complexes synthesized via one-pot homogeneous Fenton-like oxidative polymerization of an acidic aniline solution. A minimal amount of iron (0.47 wt%) made a pivotal role in the nanoribbon growth and graphitization of GCN, and deposited highly dispersed iron species on GCN without post-synthesis acid leaching, which greatly simplified the synthesis procedure of GCN with improved yield. GCN exhibited high activity and stability for catalytic degradation of organic pollutants with peroxymonosulfate (PMS) mainly via non-radical pathways. The influences of various operating parameters on the catalytic performance of GCN were investigated. Scavenging tests, spin-trapping electron paramagnetic resonance spectra, electrochemical analyses, and theoretical calculations unveiled that 1O2 was the main reactive oxygen species generated from synergistic activation of PMS on GCN while GCN-mediated electron transfer made a minor contribution to organic degradation.

Green synthesis of TiO2 nanoparticles using Echinops echinatus plant extract and its potential applications for photocatalytic dye degradation, 4-nitrophenol reduction, and antimicrobial activity

Green synthesis of TiO2 nanoparticles using Echinops echinatus plant extract and its potential applications for photocatalytic dye degradation, 4-nitrophenol reduction, and antimicrobial activity

Markers of extracellular matrix degradation and inflammasome activation are associated with carotid plaques in virally suppressed people with HIV in Botswana.

HIV is associated with increased risk of cardiovascular disease. We investigated soluble markers of extracellular matrix (ECM) remodeling and inflammation in relation to presence of carotid plaques in a well-characterized adult cross-sectional study of people with HIV (PWH) and matched people without HIV in Botswana. Using enzyme immunoassays we analyzed plasma ECM remodeling mediators including Galectin-3 (GAL-3), Cystatin B (CysB) and Growth/differentiation factor 15 (GDF-15) and the inflammatory marker IL-18 in 196 without HIV and 197 PWH of which 36 were ART-naïve. We found i) PWH had higher plasma levels of the ECM markers GAL-3 and CysB and the NLRP3 inflammasome activation marker IL-18, mainly in ART naïve participants, ii) PWH on ART had markedly higher GDF-15, associated with use of first generation nucleoside analogs; iii) high levels of CysB and IL-18 correlated with presence of carotid plaques. In PWH, high levels of CysB and IL-18 were associated with the presence of carotid plaques. For IL-18 this was observed in the study population as a whole, while the association for CysB was restricted to PWH.

Enhanced photocatalytic activity of Z-scheme BiVO4 heterophase junction via giant built-in electric field

Built-in electric field (IEF) can improve photocatalytic efficiency by promoting charge separation and transfer. Herein, a Z-scheme BiVO4 heterophase junction with giant IEF was successfully constructed. By changing the pH value of the precursor solution, the ratio of monoclinic octahedral BiVO4 (m-BVO) to tetragonal microsphere BiVO4 (t-BVO) is regulated to form a heterophase junction (mt-BVO), so as to regulate the IEF intensity. When pH = 0.5, a large number of pores were formed at the interface of the two forms in mt-BVO-35%m, so it has a larger specific surface area. mt-BVO-35%m has optimal photocatalytic tetracycline degradation activity. Under visible light irradiation, its reaction rate constant k is shown to be 3 times higher than that of pure m-BVO, and the TOC removal rate has increased from 12 % to 36 %. Through characterization, it can be proved that the IEF strength of mt-BVO-35%m is 11.86 times that of m-BVO. The significantly improved activity is mainly attributed to the presence of a giant IEF between m-BVO and t-BVO. The IEF drives the photogenerated electrons to transfer from the CB of t-BiVO4 to the VB of m-BiVO4, which greatly enhances the separation and transfer of photogenerated charge carriers. Moreover, a mechanism of Z-scheme charges transfer pathway in the mt-BVO-35%m heterophase junction was also revealed.

Isolation and characterization of a novel bacterium that promotes the degradation of poly(glycolic acid) by its extracellular esterase under thermophilic conditions

Poly(glycolic acid) (PGA) is widely utilized in the shale oil and gas industry owing to its biodegradable nature, as well as superior mechanical and barrier properties. However, PGA degradability is limited by environmental conditions such as temperature and pH, and using acids to optimize the degradation can have adverse environmental impact. Thus, it is essential to identify methods that can effectively promote the degradation of PGA under mild conditions, such as microbial degradation. In the present study, strain DB14, a bacterium that promotes PGA degradation, was isolated from drain water of a steam pipeline. Sequence analysis of the 16S rRNA gene of the bacterium revealed that it is mostly closely related to Geobacillus icigianus; however, it also differed from Geobacillus icigianus in several physiological properties. To investigate PGA degradation by strain DB14, a PGA film and disc were incubated with the strain. The residual weight of the PGA film (thickness: 170 μm) significantly reduced after incubation, whereas the decrease in the thickness of the PGA disc (thickness: 3 mm) was relatively small. The penetration of water, the bacterium, and the extracellular enzymes into the interior from the reaction-erosion front of the PGA disc may be inhibited by the high barrier performance of PGA. Strain DB14 was also found to change the pH of the surrounding environment to approximately 8–9. To investigate the effect of pH on PGA degradability, degradation tests with crude extracellular enzymes derived from strain DB14 were conducted in various buffers. The results showed that the degradation activity was highest at pH 8, which implied that DB14 efficiently maximized the hydrolytic capacity of its enzyme for degrading PGA. Thus, this study provides a basis for developing environmentally friendly technologies that can promote the degradation of PGA molding articles, especially those used in wellbores for oil and gas recovery.

Influence of gadolinium substitution on the crystal structure of NiO and its maximized photocatalytic degradation activity on tetracycline and direct yellow pollutants

Gadolinium-substituted NiO crystal structures with excellent stability were utilized for the first time to degrade antibiotic and organic dye pollutants. A simple hydrothermal technique was used to synthesize different concentrations of Gd3+ substituted NiO, and the catalysts were thoroughly characterized using sophisticated techniques to explore the influence of Gd3+ on the crystal structure and optical characteristics of NiO. The 1.5% Gd3+ substituted NiO showed outstanding photocatalytic activity on tetracycline and direct yellow degradation, with percentages of 90.72 and 95.5%, respectively. The improvement of photocatalytic degradation efficiency is primarily due to the suppression of photoinduced electron and hole recombination via the creation of Gd3+ as the inner energy band state below the conduction band. The recycling experiments revealed that the catalyst is more stable, with no indication of loss after ten cycles. Scavenging investigations also demonstrated that superoxide and holes were responsible for the efficient degradation of pollutants.

Enhancement of peroxymonosulfate activation through regulating electronic structure of cobalt phthalocyanine by g-C3N4 for rhodamine B degradation

The catalytic performance of cobalt-based catalysts in Fenton-like reactions is significantly influenced by the electron density of Co centers. However, precise control of the electronic structure to enhance the degradation activity remains a challenge. This paper demonstrates a method to enhance the catalytic activity of cobalt phthalocyanine (CoPc) by modulating its electronic structure via integrating with graphitic carbon nitride (g-C3N4). The electron redistribution between g-C3N4 and CoPc was observed, resulting in electron-rich Co centers. Consequently, the CoPc/g-C3N4 composites exhibit significantly enhanced peroxymonosulfate (PMS) activation capability compared to CoPc and their physical mixtures. The improved catalytic performance is due to the electron-rich Co centers, better dispersion of CoPc, and enhanced hydrophilicity. This study proposes a novel strategy for the design of efficient PMS activation catalysts.

Phosphorus heteroatom doped BiOCl as efficient catalyst for photo-piezocatalytic degradation of organic pollutant and unveiling the mechanism: Experiment and DFT calculation

A novel phosphorus heteroatom doped bismuth oxychloride (P-BiOCl) catalyst was synthesized and the photo-piezocatalytic degradation of rhodamine B dye performances were explored under the ultrasound vibration and light illumination. The P-BiOCl exhibited excellent photo-piezocatalytic degradation activity, such as an ultra-high reaction kinetic rate constant of 0.3961 min−1, efficient degradation efficiency (94.7 % within 8 min) and excellent stability compared to solely piezocatalysis and photocatalysis. More impressively, these outstanding performances of P-BiOCl exceeded pure BiOCl and most other catalytic materials systems. The relevant experimental and density functional theory (DFT) calculation results were exhibited to clarify enhanced photo-piezocatalytic mechanism. The introduction of P heteroatom could reduce the bandgap of BiOCl, modulate electronic structure and charge redistribution, provide novel electron channel to promote electron transfer and restrain charge carriers recombination. Additionally, P-doped could also enhance the adsorption of oxygen and water molecules, promote intrinsic catalytic activity, leading to the increased production of active free radicals ·O2– and ·OH, thus significantly boosting the efficiency of organic pollutant degradation. This work provides a comprehensive understanding of heteroatom doping enhancing photo-piezocatalytic activity and presents a potential new strategy for designing highly efficient catalysts for wastewater treatment.

Partially Bio-Based and Biodegradable Poly(Propylene Terephthalate-Co-Adipate) Copolymers: Synthesis, Thermal Properties, and Enzymatic Degradation Behavior.

A series of partially bio-based and biodegradable poly(propylene terephthalate-co-adipate) (PPTA) random copolymers with different components were prepared by the melt polycondensation of petro-based adipic acid and terephthalic acid with bio-based 1,3-propanediol. The microstructure, crystallization behavior, thermal properties, and enzymatic degradation properties were further investigated. The thermal decomposition kinetics was deeply analyzed using Friedman's method, with the thermal degradation activation energy ranging from 297.8 to 302.1 kJ/mol. The crystallinity and wettability of the copolymers decreased with the increase in the content of the third unit, but they were lower than those of the homopolymer. The thermal degradation activation energy E, carbon residue, and reaction level n all showed a decreasing trend. Meanwhile, the initial thermal decomposition temperature (Td) was higher than 350 °C, which can meet the requirements for processing and use. The PPTA copolymer material still showed excellent thermal stability. Adding PA units could regulate the crystallinity, wettability, and degradation rate of PPTA copolymers. The composition of PPTA copolymers in different degradation cycles was characterized by 1H NMR analysis. Further, the copolymers' surface morphology during the process of enzymatic degradation also was observed by scanning electron microscopy (SEM). The copolymers' enzymatic degradation accorded with the surface degradation mechanism. The copolymers showed significant degradation behavior within 30 days, and the rate increased with increasing PA content when the PA content exceeded 45.36%.

Estimation of carbon stocks and CO2 emissions resulting from the forest destruction in West Kalimantan, Indonesia

The issue of climate change has become a global concern, and tropical regions are strategically positioned to mitigate its effects through their forest resources. By maintaining the function of forest ecosystems to support life at local and regional levels, carbon stocks can be maintained, and emissions can be reduced. Above-ground biomass can bind and store carbon stocks. This study aims to analyse the CO2 emissions caused by deforestation and forest degradation in Kubu Raya District, West Kalimantan Province. Primary data was obtained through field observations, and secondary data was obtained through maps of forest areas and land cover for 1996–2021 from the Geospatial Information Agency and the Indonesian Ministry of Environment and Forestry. This study uses a non-destructive approach to calculate Above Ground Biomass. The results showed that Kubu Raya District, West Kalimantan Province, Indonesia, experienced deforestation of 235,597 ha and forest degradation of 9,860 ha from 1990 to 2021. This resulted in CO2 emissions of 163,702,815.53 tons. The highest level of CO2 emissions is in Batu Ampar District, and the lowest is in Sungai Kakap District. There is a positive correlation between the amount of deforestation and forest degradation and the level of CO2 emissions caused by these activities. This means that the amount of CO2 emissions depends on the area's deforestation and forest degradation. To reduce the concentration of CO2 in the atmosphere and its effects on climate change, deforestation and forest degradation activities in Kubu Raya Kalimantan should be stopped.

The preparation and characterization of WS2 nanomaterials with different morphologies and the mechanistic study of peroxymonosulfate activation for phenol degradation

Transitional metal chalcogenides like WS2 play a significant role as cocatalysts in activating PMS (peroxymonosulfate) due to their high reductivity. Three WS2 samples with different morphologies, specific surface areas, and 1 T phase contents were prepared in this study. Characterizations by SEM, TEM, BET, XRD, Raman, XPS, and catalytic degradation experiments confirmed that the a-WS2 sample exhibited the richest morphology, the largest specific surface area, the highest 1 T phase content, and the best cocatalytic performance. The a-WS2/Fe(II)/PMS system efficiently degraded 20 mg/L phenol within 15 minutes and was also effective in degrading pollutants like RhB (Rhodamine B) and OFX (Ofloxacin). Characterization predicted the degradation pathway of phenol and revealed 10 intermediate products. The degradation mechanism indicated that the presence of WS2 accelerated the conversion of Fe(III) to Fe(II), thereby further promoting the activation of PMS. ·SO4−, ·OH, and ·O2− were identified as the main active radicals in this system. a-WS2 exhibits characteristics such as high catalytic performance, good stability, high recyclability, and a low ion leaching rate, and it generates sulfur vacancies during use. This system shows promising prospects in the treatment of high-concentration organic wastewater.

Green Synthesis of Mn‐Doped ZnO Nanoparticles Using Ipomoea Staphylina Leaf Extract: Characterization and Application of Photocatalytic Dye Degradation, Antibacterial and Antioxidant Activity

AbstractZinc oxide nanoparticles (ZnO NPs) and manganese‐doped zinc oxide nanoparticles (Mn‐ZnO NPs) were synthesized via a cost‐effective green combustion method employing watery leaf extracts from Ipomoea Staphylina. The nanoparticles were thoroughly characterized using FT‐IR, P‐XRD, UV‐DRS, and FE‐SEM with EDX techniques. X‐ray photoelectron spectroscopy (XPS) confirmed the successful doping of Mn in ZnO NPs. Evaluation of photocatalytic efficiency revealed that ZnO NPs degraded 76 % of Congo red dye (CR), while Mn‐doped ZnO NPs exhibited a higher degradation efficiency of 92 %. The photocatalytic performance of Mn‐doped ZnO NPs surpassed that of ZnO NPs, indicating their superior photocatalytic properties. Furthermore, both ZnO and Mn‐doped ZnO NPs displayed notable antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Klebsiella pneumonia. Additionally, Mn‐doped ZnO NPs exhibited significant antioxidant activity, demonstrated by their ability to scavenge 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH⋅) free radicals. These findings suggest that biosynthesized pure and doped NPs using plant extract can be promising candidates for antibacterial and antioxidant applications in biomedical, pharmaceutical, and wastewater treatment fields.

Rational design of Zn4O(BDC)3 metal organic framework incorporated with NiCr2O4 nanoparticles: An affordable photocatalyst for the degradation of hazardous dyes

In this work, a simple hydrothermal approach was used to make Zn4O(BDC)3-NiCr2O4 nanocomposite. The structural, morphological and photophysical properties of the prepared samples were used to evaluate various characterization approaches. The Zn4O(BDC)3-NiCr2O4 nanocomposite appears to have a large surface area and increased absorption of visible light. When compared to pure Zn4O(BDC)3 and NiCr2O4, the Zn4O(BDC)3-NiCr2O4 nanocomposite displayed more effective catalytic activity for degradation of methyl orange (MO) and Rhodamine (Rh B) dye from aqueous solution when exposed to visible light. The Zn₄O(BDC)₃-NiCr₂O₄ nanocomposite achieved degradation efficiencies of 93.75 % and 89.91 % for MO and Rh B dyes, respectively, after 210 and 150 minutes of visible light irradiation. The degradation rate for MO was 0.016 min⁻¹, which is approximately 6.66 times and 3.13 times higher than that of pure Zn₄O(BDC)₃ or NiCr₂O₄ nanoparticles, respectively. In addition, the Zn4O(BDC)3-NiCr2O4 nanocomposite showed high structural stability after the degradation test, and most of its photocatalytic activity was retained even after the recycling examination. Moreover, the radical trapping experiments demonstrated that the major active species including superoxide and hydroxyl radicals played main roles in the photocatalytic process. Additionally, the photocatalytic mechanism of Zn4O(BDC)3-NiCr2O4 nanocomposite has been examined, and a more plausible path of hazardous dye degradation has been provided.