Amount Of H2O2 Research Articles

In-situ biosynthesis of metallic nanoparticles using Allium sativum and Chondrilla juncea extract: characterization and application in dye decolorization

The synthesis of catalysts has gained specific concern due to their versatile applications in particular azo dye decolorization. In the current work, metallic nanoparticles (copper and silver) were In-situ biosynthesised using Allium sativum and Chondrilla juncea extract. The obtained Allium-copper oxide and Allium-silver oxide materials were analyzed using SEM, TEM, FT-IR, TGA-DTG, SEM, TEM, and XRD techniques. Allium peels had a rough surface, with nanoparticles equally distributed over it. The crystal structure of Allium peels was altered after the addition of CuO and AgO nanoparticles. The highest residual mass values in the prepared materials indicated that the metallic nanoparticles were, in situ, formed. The prepared materials had worse thermal stability than Allium peel powders. The azo dyes, Calmagite and Naphthol Blue Black B were tested in the catalytic power of the resulting materials. The decolorization process was affected by the dye structure, amount of H2O2, dye concentration, time of reaction, and temperature of the bath. The activation energy values for Allium-CuO were 18.44 kJ mol−1 for calmagite, and 23.28 kJ mol−1 for naphthol blue black, respectively. Nevertheless, the energy values for Allium-AgO were 50.01 kJ mol−1 for calmagite and 12.44 kJ mol−1 for Naphthol blue black. The calculated low energy values for the prepared materials suggested the high efficiency of the use of these catalysts in azo dye decolorization under the change of some main experimental conditions.

Self-supported electrochemical sensor based on uniform palladium nanoparticles functionalized porous graphene film for monitoring H2O2 released from living cells.

Graphene film has been considered a promising material for the construction of self-supported electrodes due to its favorable flexibility and high conductivity. However, the film fabricated from pristine graphene or conventional graphene sheet reduced graphene oxide processes limited electrocatalytic performance. Decorating active metal species or incorporating heteroatoms intothegraphene framework have been proved to be effective methods to enhance the electrocatalytic efficiency of graphene film-based self-supported electrodes. Herein, we present a freestanding electrode composed of uniform Pd nanoparticles decorating N,S co-doped porous graphene film (Pd/NSPGF) and explore its practical application in differentiating various human colon cell types by in situ tracking the amount of H2O2 secreted from live cells. Our findings reveal that, on the one hand, the NSPGF has abundant surface and inner pores, which promote active site exposure, and mass diffusion during electrochemical reactions; on the other hand, the substitutional doping ofthe graphene framework with heteroatoms (e.g., N or S) can tailor its electronic and chemical properties, and facilitate the uniform loading of high-density Pd nanoparticles. Moreover, the intrinsic activity of Pd/NSPGF is regulated by the interaction of Pd nanoparticles withtheNSPGF support. Taking the advantages of morphology and composition, the self-supported Pd/NSPGF electrode displays remarkable electrochemical performance with a wide linear range up to 2.0mM, low detection limit of 0.1μM (S/N = 3), high sensitivity of 665 µA cm-2mM-1, and good selectivity. When applied in real-time trackingofthe H2O2 released from normal human colon epithelial cells and human colorectal cancer cells, the Pd/NSPGF-based electrochemical sensing system can distinguish the cell types by testing the number of extracellular H2O2 molecules released per cell, which holds considerable potential for early detection and monitoring of disease-related clinical specimens.

Fe/Mo bimetallic synergy system for ultra-highly efficient degradation of Rhodamine B

The traditional Fenton process, which depends on the use of Fe2+/H2O2, is constrained by the consumption of ferrous ions and the requirement for large amounts of H2O2. However, the assembly of bimetallic synergy systems with adjustable valence metal cations and enhanced dispersion of active sites has been evidenced to address these limitations. In this work, the Fe/Mo bimetallic synergy system in FexMo-CN materials is explored, utilized for the degradation of dyes with the assistance of H2O2. The cooperative effect of Fe/Mo bimetallic and the highly dispersed FeMoO4 as active sites make materials to achieve ultra-highly efficient degradation of dyes, approximately 100 % Rhodamine B (RhB) degradation within 6 min. And the corresponding degradation rate constant is 1.3471 min−1. Additionally, FexMo-CN materials exhibit excellent stability and versatility in solutions containing various cations, anions, or other dyes. Quenching experiments and EPR tests demonstrate that singlet oxygen (1O2) serves as the main reactive oxygen species (ROS) to degrade RhB. And the mechanism of generated 1O2 is revealed. The degradation path and mechanism of RhB are analyzed and the toxicology of intermediate products are calculated in detail. This work presents a novel approach for enhancing efficiency in Fenton-like reactions within the field of environmental remediation.

Copper-coordinated nanomedicine for the concurrent treatment of lung cancer through the induction of cuproptosis and apoptosis

The resistance of tumor cells to apoptosis often leads to chemoresistance and treatment failure in clinic. In this study, we have developed a Cu2+-coordinated lignosulfonate (CLS) /doxorubicin (DOX) biological complex (referred to as LCD) with the aim of overcoming cellular resistance to apoptosis for combined lung cancer therapy. The copper complexes modified by CLS exhibit significant water solubility and excellent in vivo biocompatibility. The proportion of copper in the composite is simultaneously increased. Due to the coordination and π-π stacking effects, the self-assembled LCD exhibits nanometer-scale particle size, a narrow and homogeneous grain distribution, as well as excellent dispersion stability. Furthermore, LCD has the potential to disassemble in the presence of high levels of glutathione (GSH) and low pH, leading to effective drug release. Cu2+-mediated cuproptosis can lead to the down-regulation of FDX1 and DLAT protein expression by reducing mitochondrial membrane potential, resulting in non-apoptotic programmed cell death (PCD) regardless of cellular resistance to apoptosis. Moreover, the released DOX not only exhibits a preference for localizing in the cell nucleus to induce apoptosis for combined chemotherapy, but also generates a substantial amount of H2O2. This H2O2 further produces ROS to induce apoptosis through Fenton reaction with Cu2+. LCD demonstrates significant superiority over monotherapy in inhibiting tumor growth while minimizing systemic toxicity through the combined action of cuproptosis and apoptosis. This study may provide a potential avenue for the advancement of self-delivery nanomedicine to overcome resistance to apoptosis in tumor therapy.

Effects of Pressure, Hypoxia, and Hyperoxia on Neutrophil Granulocytes

Background: The application of normo- and hyperbaric O2 is a common therapy option in various disease patterns. Thereby, the applied O2 affects the whole body, including the blood and its components. This study investigates influences of pressure and oxygen fraction on human blood plasma, nutrient media, and the functions of neutrophil granulocytes (PMNs). Methods: Neutrophil migration, reactive oxygen species (ROS) production, and NETosis were examined by live cell imaging. The treatment of various matrices (Roswell Park Memorial Institute 1640 medium, Dulbecco’s Modified Eagle’s Medium, H2O, human plasma, and isolated PMNs) with hyperbaric oxygen (HBO) was performed. In addition, the expression of different neutrophil surface epitopes (CD11b, CD62L, CD66b) and the oxidative burst were investigated by flow cytometry (FACS). The application of cold atmospheric plasma (CAP) to normoxic and normobaric culture media served as a positive control. Soluble reaction products such as H2O2, reactive nitrogen species (RNS: NO2− and NO3−), and ROS-dependent dihydrorhodamine oxidation were quantified by fluoro- and colorimetric assay kits. Results: Under normobaric normoxia, PMNs migrate slower and shorter in comparison with normobaric hyper- or hypoxic conditions and hyperbaric hyperoxia. The pressure component has less effect on the migration behavior of PMNs than the O2 concentration. Individual PMN cells produce prolonged ROS at normoxic conditions. PMNs showed increased expression of CD11b in normobaric normoxia, lower expression of CD62L in normobaric normoxia, and lower expression of CD66b after HBO and CAP treatment. Treatment with CAP increased the amount of ROS and RNS in common culture media. Conclusions: Hyperbaric and normobaric O2 influences neutrophil functionality and surface epitopes in a measurable way, which may have an impact on disorders with neutrophil involvement. In the context of hyperbaric experiments, especially high amounts of H2O2 in RPMI after hyperbaric oxygen should be taken into account. Therefore, our data support a critical indication for the use of normobaric and hyperbaric oxygen and conscientious and careful handling of oxygen in everyday clinical practice.

Controlled Etching of Gold Nanorods Within Mesoporous Silica Shells at Mild Conditions

AbstractSurface plasmon resonance of precious metal gold nanorods can be tuned by controlling the aspect ratio, and they find widespread applications in biotechnology, imaging, sensing, optoelectronics, photonics, and catalysis. Here, a method is proposed for the controlled etching of gold nanorods within mesoporous silica shells by using a certain concentration of H2O2 at room temperature. In the experiments, the amount of HCl is varied to adjust the acidity and/or change the amount of H2O2 to control the speed of corrosion, achieving controllable adjustment of the aspect ratio of the gold nanorods. The extinction spectra show that under the action of H2O2 and HCl, the longitudinal plasmonic resonance of the gold nanorods shifted to shorter wavelengths, and the intensity of the longitudinal plasmonic resonance decreased. The more hydrochloric acid or hydrogen peroxide added, the faster the corrosion rate of the gold nanorods, and the faster the blue shift of the longitudinal plasmonic resonance. In addition, the intensity of the extinction spectra at 320 nm increased linearly versus time, which can also be used to monitor the etching process. By corroding gold nanorods to control the plasmonic resonances, gold nanorods can find broader applications.

A photocatalysis-self-Fenton system based on NCDs@ZnIn2S4 composites at neutral pH and low amount of Fe2+ for the effective degradation of antibiotics

Photocatalysis-self-Fenton combining photocatalytic production of H2O2 with Fenton reaction has been a hotspot, but the pH limitation and iron sludge production problems remain unsolved. Herein, we proposed a self-fenton system based on N-doped carbon dots modified ZnIn2S4 (NCDs@ZnIn2S4) composites that exhibits effective degradation of antibiotics under neutral pH using low amounts of Fe2+. The decoration of ZnIn2S4 with NCDs significantly increased the surface area, visible light absorption, charge transfer ability and oxygen adsorption ability. NCDs@ZnIn2S4 composites exhibited a high H2O2 production rate (1528 μM g−1•h−1) under visible light, which was 1.9 and 5.3 times higher than ZnIn2S4 and NCDs, respectively. Meanwhile, the Fe2+/NCDs@ZnIn2S4 system with a low concentration of Fe2+(1 mg/L) could remove over 95% levofloxacin and oxytetracycline within 30 min. Interestingly, the highest degradation efficiency occurred under neutral pH. Quenching experiments and analytical measurements indicated that the high catalytic performance under pH = 7 with low amounts of Fe2+ stemmed from the higher amount of inner-generate H2O2 under neutral pH and easy regeneration of Fe2+ by photoinduced electrons for high •OH yields. Additionally, the Fe2+/NCDs@ZnIn2S4 system exhibited high degradation performance under different water matrix and ultrahigh degradation efficiency towards levofloxacin under real sunlight irradiation. The work shows the prospects of photocatalysis-self-Fenton systems for overcoming the pH limitation and the difficulty of iron sludge separation in the purification of effluents.

Generation of H2O2 via simultaneous treatment of cotton and organic pollutants in textile wastewater

The textile industry is essential for human life but generates significant amounts of waste cotton and alkaline dye wastewater. These pollutants are difficult to separate and treat, causing numerous environmental issues. Traditional methods struggle to deal with the combined pollution without additives. In this study, we developed a simple hydrothermal process to convert waste cotton and dye wastewater into a non-metal catalyst. This catalyst can degrade dyes using oxygen from the air. Remarkably, it produces a substantial amount of H2O2 after degrading the dyes. This demonstrates that we utilized waste cotton present in textile wastewater as a catalyst precursor and abundant oxygen as an oxidant to convert dye wastewater into valuable H2O2. We also used commercially available cotton cloth as a raw material and achieved good results. Under the optimized conditions, 96 % of the dye was degraded within 4 h, generating 252 μM of H2O2 simultaneously. Additionally, the catalysts performed better under alkaline conditions, with the dye degradation rate increasing by 33 % compared to neutral conditions. This is ideal for alkaline textile mill wastewater. Therefore, our work provides a novel method for the treatment of cotton waste and dyes in textile mills and has broad application prospects.

Constructing Cu-Mn bimetallic synergistic sites in 2D metal-organic framework nanosheets to induce polarized charge distribution: Electronic structure transformation and evaluation of Fenton-like performance

Heterogeneous Fenton-like process based on H2O2 was an efficient method for the abatement of micropollutants in water. However, the mass transport resistance caused by the limited access between catalytic sites and target chemicals still restrict the decontamination efficiencies. Metal-organic frameworks (MOFs) with uniformed pores and anbundant metal sites shows great potentail in environmental remediation, Here, a novel two-dimensional nanosheet consisting of Cu and Mn bimetallic-oxygen clusters (CuMn-BDC, BDC refers to terephthalic acid organic ligand) was rationally designed and characterized. The introduction of second metal Mn changed the surface electronic distribution and accelerated the electron transfer of pristine Cu-based nanosheet, leading to improved catalytical acticities and removal effeciencies (kSA) for Sulfamethoxazole (SMX). The catalytic activity of CuMn-BDC obtained (5.76 × 10–4) was 3.95 times higher than that of Cu-BDC (1.46 × 10–4), demonstrating that the CuMn-BDC showed higher reaction rates than that of Cu-BDC when same amount of H2O2 was added. The interfacial micro-electric fields in bimetallic MOFs increased the interaction of organic pollutants and transfer the electron to activate H2O2. Several quenching experiments, electron paramagnetic resonance spectra and theoretical calculations were performed to study the reaction mechanism systematically. Further the powder was fabricated into membrane with higher water stablities. This study shed light on develop efficient 2D-MOFs catalyst for the abatement of micropollutants in water.

Rapid Preparation of Porous Graphene by Microwave‐Assisted Chemical Etching for Electrochemical Energy Storage

AbstractPorous graphene materials possess a larger specific surface area and a more abundant presence of active sites compared to non‐porous graphene materials, resulting in enhanced electrochemical properties. The presence of in‐plane nanopores facilitates the transmission of ions and mass, further expanding the potential applications of graphene materials in electrochemical energy storage and various other fields. In this study, a rapid synthesis of porous graphene was achieved through a microwave‐assisted chemical etching method. With the aid of microwave radiation, the etchant efficiently reduced the oxygen‐containing groups within the graphene structure, consequently generating nanopores with an approximate diameter of 10 nm. By optimizing the microwave treatment parameters, including pretreatment time, etching time, amount of etchant H2O2, and microwave power, the area percentage of nanopores in the graphene material was controlled to enhance its electrochemical properties. Porous graphene materials exhibited excellent specific capacitance and rate capability, making it a promising material for capacitor applications. Moreover, the lower internal resistance of porous graphene, compared to non‐porous graphene, demonstrated the significant role of nanopores in enhancing the electrochemical performance. These findings highlight the potential of porous graphene for use in electrochemical energy storage.

A fluorimetric and colorimetric dual-mode sensor based on N, S co-doped carbon dots functionalized silver nanoparticles for glucose detection

A fluorescent-colorimetric dual-signal platform, N, S co-doped carbon dots functionalized silver nanoparticles (NS-CDs-AgNPs), was designed in situ by reducing AgNO3 in the presence of N, S co-doped carbon dots (NS-CDs) under the assistance of microwave irradiation for glucose determination. With the formation of silver nanoparticles (AgNPs), the intrinsic fluorescence of NS-CDs was quenched, showing the fluorescence state was off. Whereas the fluorescence of NS-CDs can be switched on when a trace amount of H2O2 was added. Based on this novel phenomenon, the peroxidase-like activity of NS-CDs-AgNPs by using 3,3′,5,5′-tetramethylbenzidine (TMB) chromogen and H2O2 as substrates was evaluated. The Km values of the prepared probe for H2O2 and TMB were 0.84 mM and 0.01 mM with the Vm of 6.65 × 10−8 M S−1 and 3.01 × 10−8 M S−1, respectively. The results showed that NS-CDs-AgNPs had good peroxidase-like activity and strong affinity to TMB and H2O2. It confirmed that there is a redox interaction between AgNPs and H2O2, and H2O2 can oxidize Ag to produce Ag+, which is the main reason that the fluorescence of NS-CDs-AgNPs can be activated by H2O2. The hydroxyl radical (·OH) was formed in the process of reaction, which can further oxidize TMB for color reaction. Meanwhile, glucose can be oxidized to produce H2O2 in the presence of glucose oxidase (GOx). Based on the phenomenon, a fluorimetric and colorimetric dual-mode sensor for glucose detection was established. Satisfactory results were obtained with the linear range of 0.1–80 μM for fluorimetric mode and 0.5–5 μM for colorimetric mode, respectively. Additionally, the LOD was below 0.32 μM and 0.21 μM, respectively. The method was successfully applied to determine the glucose in human serum with satisfactory recovery and RSD.

Synthesis of biochar-doped MgO catalyst for highly efficient conversion of glucose into formic acid at low temperatures

Formic acid (FA) is not only a significant platform chemical but also a promising candidate for hydrogen storage. Although homogeneous catalysts are commonly employed for the conversion of carbohydrate biomass into FA, which often come with substantial costs and inadequate reusability. It is noteworthy that there has been an increasing focus on the development of heterogeneous catalysts in this area, which aim to address these limitations and offer advantages such as easier separation and better reusability. Herein, an eco-friendly and efficient method for the catalytic conversion of glucose to FA by utilizing a biochar-MgO (BC-MgO) catalyst, which is prepared through pyrolysis of coconut husk biochar impregnated with magnesium chloride (MgCl2), is proposed. The FA yield at 74.6% is attained from glucose at 60 °C within only 3 h, utilizing a mere 0.1 g of catalyst and hydrogen peroxide (H2O2) amount of 100%. In conjunction with random forest (RF) algorithms and box-behnken experimental designs, further optimization resulted in an increased yield of 79.1%, with a selectivity of 82.7%, in only 3.8 h at 67 °C, employing 0.1 g of catalyst amount and 125% H2O2 amounts. Notably, the BC-MgO catalyst retains its catalytic efficiency over multiple cycles, only requiring a simple straightforward regeneration procedure. The mechanism underlying the glucose conversion to FA reaction system is demystified via kinetic modeling, time-gradient studies, and model compounds experiments. Life cycle assessment (LCA) indicates that when used for glucose conversion to FA, BC-MgO catalysts generate lower CO2 emissions than traditional homogeneous catalysts such as LiOH. Concurrently, an operation cost analysis indicates that operation cost of FA production from glucose is 4.1 $/kg with the BC-MgO catalyst, which is lower than LiOH catalyst (7.5 $/kg), evidencing the dual advantage of economic viability and an improved environmental impact inherent to this novel process.

The Possible Protective Role of N-acetylcysteine against Testicular Toxicity Induced by Paracetamol Overdose in Adult Male Rats

Many substances, even medicines with proven therapeutic benefits, can harm cells by metabolically activating them into extremely reactive substances. Paracetamol is one of the most widely used over-the-counter analgesics. This study examines the harmful effects of paracetamol on the lipid peroxidation process in testes homogenates as well as enzymatic and non-enzymatic antioxidant activities. Also, examine the effects on male hormones and sperm count. The study also assesses if N-acetylcysteine protects against testicular damage induced by paracetamol excess. Forty mature male albino rats were created. Group 1 as a control, Group 2 paracetamol (650 mg/kg), Group 3 NAC (150 mg/kg), and Group 4 both paracetamol and NAC. Samples of blood and testicles were taken after 15 days to measure sperm and testicular biochemistry. Testicular tissues had considerably higher amounts of MDA and H2O2. SOD, GSH, and CAT levels significantly decreased. FSH and LH rise. On the other hand, testosterone levels decrease following paracetamol exposure. The administration of NAC generated changes in testosterone levels, FSH, LH, and antioxidant enzymes. The sperm morphology showed an increase in abnormalities but a significant decrease in motility and count. NAC effectively lowers the toxicity of paracetamol to the testicles while restoring biomarkers associated with normal testicular function.

Synthesis of strongly interactive FeWO4/BiOCl heterostructures for efficient photoreduction of CO2 and piezo-photodegradation of bisphenol A

Development of multi-functional photocatalysts for CO2 reduction and pollutant elimination is practically significant for solving the environmental problems and energy shortages. In this study, we have immobilized FeWO4 (FWO) nanoparticles on the surface of (001)-facet-exposed BiOCl (BOC) nanosheets through their strong electrostatic interaction to form FWO/BOC heterojunctions. Experimental and theoretical studies corroborate that the FWO/BOC heterojunctions exhibit high-efficiency Z-scheme transfer and separation of photocarriers, and possess excellent photocatalysis for CO2 reduction and bisphenol A (BPA) degradation. Under simulated-sunlight irradiation, the 9 %FWO/BOC heterojunction exhibits a photoreduction performance with CH4/CO yield rates of 4.25/9.41 μmol g−1 h−1 (5 h reaction), which are 3.86/5.26 times higher than those for bare BOC; whereas its photodegradation performance (η(60 min) = 66.8 %, kapp = 0.01755 min−1) is enhanced by 4.3 and 2.7 times compared with that of bare FWO and BOC, respectively. Furthermore, when ultrasonic vibration is simultaneously employed during the simulated-sunlight illumination, the ultrasonic-induced piezoelectric polarization field in BOC nanosheets accelerates the bulk photocarrier separation, resulting in a further improvement in the BPA degradation, and the calculated SF = 1.79 quantifies the degree of enhancement achieved by piezo-photocatalysis collaboration. The introduction of a moderate amount of H2O2 or peroxymonosulfate (PMS) in the reaction solution plays a significant role in promoting the BPA degradation due to the generation of additional •OH and •SO4− reactive species. The mechanisms for photocatalytic CO2 reduction and piezo-photodegradation of BPA catalysis were deeply studied by combining experiments and theory.

New strategy to optimize in-situ fenton oxidation for TPH contaminated soil remediation via artificial neural network approach

In-situ remediation of total petroleum hydrocarbon (TPH) contaminated soils via Fenton oxidation is a promising approach. However, determining the proper injection amount of H2O2 and Fe source over the Fenton reaction in the complex geological conditions for in-situ TPH soil remediation remains a daunting challenge. Herein, we introduced a practical and novel approach using soft computational models, a multilayer perception artificial neural network (MPLNN), for predicting the TPH removal performance. In this study, we conducted 48 sets of TPH removal experiments using Fenton oxidation to determine the TPH removal performance of a wide range of different ground conditions and generated 336 data points. As a result, a negative Pearson correlation coefficient was obtained in the Fe injection mass and the natural presence of Fe mineral in the soil, indicating that the excess of Fe could significantly retarded the TPH removal performance in the Fenton reaction. In addition, the MPLNN model with 6-6-1 training using Scaled conjugate gradient backpropagation (SCG) with tangent sigmoid as the transfer function demonstrated a high accuracy for TPH removal prediction with the correlation determination of 0.974 and mean square error value of 0.0259. The optimized MPLNN model achieved less than 20% error for predicting TPH removal performance in actual TPH-contaminated soil via Fenton oxidation. Hence, the proposed MPLNN can be useful in improving the Fenton oxidation of TPH removal performance in-situ soil remediation.

Photodegradation of a Broad-Spectrum Antibiotic Azithromycin Using H2O2 under Ultraviolet Irradiation.

The photodegradation of azithromycin present was carried out in water using H2O2 under UV irradiation. The reaction variables considered in this study were the amount of H2O2 solution and the initial concentration of azithromycin to evaluate the performance of the photodegradation process. The azithromycin degradation was not observed in the dark during stirring for 20 min. The study showed an efficient photodegradation of azithromycin using H2O2 as an oxidant in the presence of UV irradiation. The azithromycin degradation was altered significantly by the pH of the irradiated solution. The degradation was low at an acidic pH and showed an increasing trend as the pH changed to basic. The azithromycin degradation increased with a higher amount (higher concentration) of H2O2. The degradation of azithromycin decreased with a higher concentration of azithromycin in the reacting solution. The highest degradation of AZT was achieved in 1 h using a 1.0 ppm AZT solution containing 3 mL of H2O2. The experimental data obtained were well-fitted to zero-order reaction kinetics. The results of this study were found quite excellent. They showed 100% degradation in 1 h when compared with those reported in the literature, both with photocatalysis using nanomaterials and photolysis using light irradiation and/or H2O2. The UV/H2O2 system was found to be quite efficient for the photodegradation of azithromycin, and this system can be applied to degrade other organic pollutants present in industrial wastewater.

Electrocatalytic degradation of ofloxacin by self-doped copper/carbon cathode materials derived from waste printed circuit boards

Using residual copper metal from waste circuit boards, ordered carbon materials containing copper (PCBs-Cu-800) were synthesized by self-doping for the electrocatalytic degradation of ofloxacin (OFL). Although PCBs-Cu-800 has a smaller specific surface area, its efficiency in degrading OFL was higher than that of carbon materials without copper (PCBs-800), reaching 95.9 % within 2 h. The PCBs-Cu-800 electrode can generate a large amount of H2O2 in the initial stage of degradation, thereby increasing the amount of hydroxyl radicals (·OH) generated and removing OFL. Density functional theory simulations were used to calculate the adsorption energies of O2 on both materials, demonstrating that the self-doped copper model was more prone to O2 adsorption, and elucidating the excellent electrocatalytic performance of PCBs-Cu. The residual copper metal in the raw material is important in the electrocatalytic processes. This study presents an environmentally friendly catalytic material capable of effectively degrading OFL in solution using waste circuit boards and further expands the application scope of advanced electrochemical oxidation technology in wastewater treatment.

Enhanced Glycosylation Caused by Overexpression of Rv1002c in a Recombinant BCG Promotes Immune Response and Protects against Mycobacterium tuberculosis Infection.

Tuberculosis (TB) is a major global health threat despite its virtual elimination in developed countries. Issues such as drug accessibility, emergence of multidrug-resistant strains, and limitations of the current BCG vaccine highlight the urgent need for more effective TB control measures. This study constructed BCG strains overexpressing Rv1002c and found that the rBCG-Rv1002c strain secreted more glycosylated proteins, significantly enhancing macrophage activation and immune protection against Mycobacterium tuberculosis (M. tb). These results indicate that Rv1002c overexpression promotes elevated levels of O-glycosylation in BCG bacteriophages, enhancing their phagocytic and antigenic presentation functions. Moreover, rBCG-Rv1002c significantly upregulated immune regulatory molecules on the macrophage surface, activated the NF-κB pathway, and facilitated the release of large amounts of NO and H2O2, thereby enhancing bacterial control. In mice, rBCG-Rv1002c immunization induced greater innate and adaptive immune responses, including increased production of multifunctional and long-term memory T cells. Furthermore, rBCG-Rv1002c-immunized mice exhibited reduced lung bacterial load and histological damage upon M. tb infection. This result shows that it has the potential to be an excellent candidate for a preventive vaccine against TB.

Magnetically separable Z-scheme ZnFe2O4/MoS2 photocatalyst for boosting photo-Fenton degradation activity by a hole-mediated mechanism

The development of high-efficiency and robust photocatalysts is imperative and challenging in advanced oxidation processes (AOPs). Herein, magnetically separable ZnFe2O4/MoS2 photocatalyst was prepared by a simple hydrothermal method. The degradation characteristics of several organic pollutants (rhodamine B (RhB), methyl orange, methylene blue, and antibiotic tetracycline) were investigated with/without the addition of H2O2 under visible light irradiation. It is found that the synergistic effect of Z-scheme ZnFe2O4/MoS2 photocatalyst and photo-fenton-like reaction promotes the decomposition of H2O2, accelerates the separation efficiency of photogenerated electrons and holes, and thus improves the photocatalytic activity. The RhB photo-degradation of the constructed Z-scheme ZnFe2O4/MoS2 (96.3%) photocatalyst in the absence of H2O2 for 100min is better than that of MoS2 (74.8%) and ZnFe2O4 (6.2%), with a rate constant of 0.0332min-1. The slight amount of H2O2 boosts the photocatalytic performance significantly. Its degradation rate is 98.6% within 8min with the rate constant of 0.396min-1, 12 times higher than that of ZnFe2O4/MoS2 photocatalyst without H2O2. The magnetic separation, recycling stability and neutral solution process are also confirmed in ZnFe2O4/MoS2 system, indicating the enormous potential of this photocatalyst in environmental remediation and waste water treatment. The hole-mediated oxidation mechanism has been proposed instead of conventional active radicals of •OH based on the free radicals capture and electron spin resonance experiments. MoS2 plays a crucial role in facilitating the H2O2 decomposition and realizing the conversion circulation from Fe3+ to Fe2+ by the redox cycling as a co-catalyst. This study provides insights into the photocatalytic mechanism of Z-scheme photo-Fenton heterojunction photocatalysts, conducive to the development of high-efficient and stable photocatalysts in AOPs.

Study on the Technology of Ultrasonic, Chemical and Mechanical Combined Treatment of Oilfield Aging Oil

Aging oil is a common pollutant in petrochemical enterprises due to its severe emulsification and flocculation, poor settling performance, low oil recovery rate, and high difficulty in treatment. This article adopts the method of mechanical, ultrasonic, and chemical coupling demulsification to treat aging oil, with the water content and oil recovery rate of the treated aging oil as the inspection indicators. The experiment shows that when the oil-water ratio is 1:4, the heating temperature is 50℃, the stirring speed is 180rpm, the ultrasonic frequency is 25kHz, the power is 40W, the ultrasonic time is 25min, and the pH is adjusted to 3-4. The additional amount of FeSO4 is 160mg/L, the additional amount of H2O2 is 0.11%, and the heating stirring reaction is 40min. When the dosage of cationic PAM with an ion degree of 50 is 35mg/L, the centrifugation speed is 3200rpm. The centrifugation time is 20 min, the crude oil recovery rate after aging oil treatment can reach over 94.6%, and the water content of the treated crude oil is less than 0.5%, meeting the standards for crude oil gathering and transportation in China. The oil content in the water generated after aging oil treatment is about 150 mg.L-1, the suspended solids content is 200 mg.L-1, the oil content in the residue is 6%, and the water content is 53%. By analyzing the appearance of aging oil before and after treatment, it was found that when using this process to treat aging oil, the original spatial cross-linking network structure of the aging oil was broken, allowing the water droplets wrapped in the oil to be released, thereby significantly reducing the water content in the recovered oil and improving the oil recovery rate.