Amount Of Catalyst Research Articles

Design and fabrication of electrochemical sensor based on NiO/Ni@C-Fe3O4/CeO2 for the determination of niclosamide

In this study, we aimed to enhance and accelerate the electrochemical properties of a glassy carbon-based voltammetric sensor electrode. This was achieved through the modification of the electrode using a nanocomposite derived from a metal–organic framework, which was embedded onto a substrate consisting of metal oxide nanoparticles. The final product was an electrocatalyst denoted as NiO/Ni@C-Fe3O4/CeO2, tailored for the detection of the drug niclosamide. Several techniques, including FT-IR, XRD, XPS, FE-SEM, TEM, and EDS, were employed to characterize the structure and morphology of this newly formed electroactive catalyst. Subsequently, the efficiency of this electrocatalyst was evaluated using cyclic voltammetry and electrochemical impedance spectroscopy techniques. Differential pulse voltammetry was also utilized to achieve heightened sensitivity and selectivity. A comprehensive exploration of key factors such as the catalyst quantity, optimal instrumental parameters, scan rate influence, and pH effect was undertaken, revealing a well-regulated reaction process. Furthermore, the sensor's analytical performance parameters were determined. This included establishing the linear detection range for the target compound within a specified concentration interval of 2.92 nM to 4.97 μM. The detection limit of 0.91 nM, repeatability of 3.1%, and reproducibility of 4.8% of the sensor were calculated, leading to the observation of favorable stability characteristics. Conclusively, the developed electrochemical sensor was successfully employed for the quantification of niclosamide in urine samples and niclosamide tablets. This application highlighted not only the sensor’s high selectivity but also the satisfactory and accurate outcomes obtained from these measurements.

Synthesis of HNTs-Ca/Zn catalyst for biodiesel production from acidulated palm oil: Optimized by GA-BP

The development of heterogeneous base catalyst with acid resistance has become a major topic in the current research on the biodiesel production process. Halloysite nanotubes (HNTs) is supported with bimetallic of calcium and zinc for modification and labeled as HNTs-Ca/Zn to show both the acid and base characteristics. Further, this supported catalyst is used to produce biodiesel from the acidulated palm oil through catalyzing transesterification in one-step in this study. The HNTs-Ca/Zn catalyst, synthesized by the impregnation method, is characterized by TG-DTG, XRD, XPS, TEM, SEM-EDX, nitrogen adsorption-desorption, CO2/NH3-TPD, FTIR and Raman. The capability of the HNTs-Ca/Zn catalyst in catalyzing transesterification is investigated, where the maximum yield of 95.22% is achieved with the molar ratio of Zn to Ca of 1.5. The advantage of HNTs-Ca/Zn1.5 catalyst is prominent when the transesterification source oil is acidulated, where the biodiesel yield of 92.66% is obtained even at the acid value of 26.02 mg KOH g−1. Besides, reusability of the catalyst is acceptable, where the yield of 77.91% is maintained after the fourth reused cycle. Further, the Genetic Algorithm-Back Propagation (GA-BP) neural network is used to train and predict the transesterification parameters of the reaction temperature, catalyst amount and methanol to oil molar ratio. The prediction of the biodiesel yield is reasonable. At the predicted reaction parameters of 158 °C, catalyst amount of 7.1 wt.% and methanol to oil molar ratio of 15.5, the predicted biodiesel yield is 98.71%, where the experimental verification value is 98.60%. Therefore, the HNTs-Ca/Zn catalyst is considered to demonstrate exceptional catalytic performance and recyclability, offering the potential for biodiesel production.

Immobilization of ionic liquids (ILs) on magnetic mesoporous silica nanotubes: A high throughput and reusable nanocatalyst for the green synthesis of indeno[1,2-b]indolone derivatives

The acidic ionic liquid supported on the magnetic mesoporous silica nanotubes (M-MSNTs/IL) was prepared as a new magnetic catalyst and fully characterized with FE-SEM, HR-TEM, EDS, TGA, BET, VSM, FT-IR, EDX, elemental mapping and XPS. The template of catalyst was magnetic aminated MWCNTs (M-MWCNTs/CONHBu), which removed through calcination process and magnetic mesoporous silica nanotubes (M-MSNTs) were obtained and functionalized using adenine based ionic liquid. The prepared catalyst was successfully applied as a new reusable heterogeneous catalyst for the one-pot three-component indeno[1,2-b]indole-9,10-dione derivatives in water at 75 °C. All of desired products were obtained in good to excellent yields (79–96 %) after relatively short reaction times. M-MSNTs/IL also exhibited a remarkable performance with TOF of 61.2 h-1 and TON of 86.7. The use of M-MSNTs/IL catalyst in the synthesis of indeno[1,2-b]indole-9,10-dione derivatives revealed several advantages including mild reaction conditions, high yield of pure products, clean reaction conditions, avoiding the production of toxic waste, chemical stability of the catalyst, low amount and reusability of catalyst. In addition, the applied nanocatalyst was recovered with an external magnet and reused 6 times without considerable reduction in its catalytic activity.

Catalase Detection via Membrane-Based Pressure Sensors.

Membrane-based sensors (MePSs) exhibit remarkable precision and sensitivity in detecting pressure changes. MePSs are commonly used to monitor catalytic reactions in solution, generating gas products crucial for signal amplification in bioassays. They also allow for catalyst quantification by indirectly measuring the pressure generated by the gaseous products. This is particularly interesting for detecting enzymes in biofluids associated with disease onset. To enhance the performance of a MePS, various structural factors influence membrane flexibility and response time, ultimately dictating the device's pressure sensitivity. In this study, we fabricated MePSs using polydimethylsiloxane (PDMS) and investigated how structural modifications affect the Young's modulus (E) and residual stress (σ0) of the membranes. These modifications have a direct impact on the sensors' sensitivity to pressure variations, observed as a function of the volume of the chamber (Σ) or of the mechanical properties of the membrane itself (S). MePSs exhibiting the highest sensitivities were then employed to detect catalyst quantities inducing the dismutation of hydrogen peroxide, producing dioxygen as a gaseous product. As a result, a catalase enzyme was successfully detected using these optimized MePSs, achieving a remarkable sensitivity of (22.7 ± 1.2) µm/nM and a limit of detection (LoD) of 396 pM.

Green synthesis of solketal from glycerol using metal-modified ZSM-5 zeolite catalysts: process optimization.

This study investigates the production of solketal (2,2-dimethyl-1,3-dioxolane-4-methanol) from glycerol via ketalization reaction using M-ZSM-5 catalysts (M = Fe, Co, Ni, Cu, and Zn). The wet impregnation method ensured precise metal loading and versatility in catalyst preparation. We present a novel approach by employing a suite of characterization techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), Thermogravimetric analysis (TGA), and Field-emission scanning electron microscopy (FE-SEM), to elucidate the catalyst's structure, bonding, surface area, thermal stability, and morphology, ultimately linking these properties to their performance. Solketal synthesis was optimized in a reactor, with parameters like temperature, glycerol:acetone molar ratio, catalyst amount, reaction time, and stirring speed. Optimal conditions were identified as 60°C, 1:4, 0.2g, 60min, and 1200rpm, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis confirmed successful solketal formation. Among M-ZSM-5 catalysts tested, Cu-ZSM-5 emerged the most efficient, achieving an impressive 99% glycerol conversion and 96% solketal selectivity. Notably, Cu-ZSM-5 catalyst displayed exceptional reusability, regaining its initial activity through calcination, thus minimizing waste generation. This research unveils Cu-ZSM-5 as a highly efficient catalyst and promotes sustainability by utilizing a renewable glycerol feedstock to produce valuable solketal with applications in fuel additives, solvents, and pharmaceuticals. This work paves the way for developing environmentally friendly processes for waste valorization and producing valuable bio-based chemicals.

Structural study and photocatalytic activity of BiMeVOx materials[formula omitted

We focused on the synthesis of copper and tantalum doped bismuth vanadate and on its photocatalytic activity. The solid-state reaction is used to synthesize Bi4V2 - xCux2Tax2O11 -3x4 where Cu2+ and Ta5+ replace the vanadium (V5+) in the in perovskite-like layers. The phase transformation from α to γ is determined by X-ray diffraction and Fourier transform infrared spectroscopy. This transformation is due to the incorporation of Cu2+ and Ta5+ in the Bi4V2O11 lattice. Scanning electron microscopy was used to investigate the morphology, and elemental compositions of the synthesized photocatalysts. The bandgap energies of BiCuTaVOx are between 2.00 and 2.10 eV, they have been determined by using UV–visible diffuse reflectance spectroscopy. How the rate of substitution between Cu2+ and Ta5+ affects photocatalytic activity was investigated. The impact of the substitutions simple and double by copper and tantalum, was then examined for Bi4V1.7Cu0.3O10.55, Bi4V1.7Ta0.3O11, and Bi4V1.7(Cu-Ta)0.3O10.775. Copper and tantalum play a synergic effect on photodegradation of Sulfamethoxazole. The effect of physical factors including the catalyst amount and pH on the photocatalytic degradation under UV–visible was studied. However, Bi4V1.7Cu0.15Ta0.15O10.775 also exhibits a photocatalytic activity under visible light irradiation using 0.8 g/l of photocatalyst at pH10. The degradation reaches 65 % in the optimal conditions under visible light irradiation during 5 h.

Carbon Dioxide Pressure and Catalyst Quantity Dependencies in Artificial Photosynthesis of Hydrocarbon Chains on Nanostructured Co/CoO Surfaces.

In this study, we investigated the influence of pressure and the quantity of Co/CoO catalyst on an artificial photosynthesis process that converts CO2 and H2O into hydrocarbons (CnH2n+2, where n ≤ 18). The adsorption of CO2 and H2O on Co/CoO surfaces proved to be pivotal in this photo-catalytic reaction. Photoexcited carbon dioxide and water molecules ((CO2)* and (H2O)*) generated by illuminating the catalyst surface led to the formation of alkene hydrocarbon molecules with carbon numbers following an approximate Poisson distribution. The optimal pressure was found to be 0.40 MPa. Pressure less than 0.40 MPa resulted in low CO2 adsorption, impeding excitation for photosynthesis. At greater pressure, oil/wax accumulation on Co/CoO surfaces hindered CO2 adsorption, limiting further photosynthesis reactions. The average number of carbon atoms in the hydrocarbons and hydrocarbon yield were correlated. The amount of Co/CoO was also found to affect the hydrocarbon yield. Our study contributes to the understanding of Co/CoO-catalyzed photosynthesis and suggests that an open-flow system could potentially enhance the productivity of long-chain hydrocarbons.

Production of NiCoMo-Supported Ni Foam for Electrocatalytic Oxidation of Methanol: Experimental and RSM Analysis

The Ni-, Co-, and Mo-supported Ni foam (NiF–NiCoMo) was produced via galvanostatic method, and electrooxidation of methanol in alkaline medium was examined. The characterization was achieved using field emission scanning electron microscopy, energy-dispersive X-ray, and X-ray diffraction analysis. The electrochemical behavior was determined via cyclic voltammetry and chronoamperometry analysis. The contribution of each transition metal to electrocatalytic performance of NiF was monitored via mono, binary, and ternary modifications of each transition metal (Ni, Co, and Mo) for several amounts (5, 10, and 15 μg). Experiments were performed to determine the influence of catalyst amounts, methanol concentration, and scan rate parameters. The impacts of independent parameters on methanol electrooxidation were statistically investigated using Design-Expert software. The ability to analyze multiple parameters with a limited number of experimental performances is one of the method’s key benefits. The developed model showed that 9.41 and 14.03 µg catalyst amounts were the appropriate values for NiF–NiMo and NiF–NiCoMo achieving optimal circumstances, respectively.

Synthesis, characterization of poly l(+) lactic acid and its application in sustained release of isosorbide dinitrate

Poly l(+) lactic acid (PLLA) has become crucial in the biomedical industry for various uses. The direct polycondensation method was used to prepare Poly l(+) Lactic Acid (PLLA). Different catalysts, including metal oxides and metal halides, were used to test the polymerization technique. The effect of the amount of catalysts and the type of coupling agent were investigated. The effect of reaction time and polymerization solvents was also studied. PLLA was loaded with isosorbide dinitrate utilizing the solvent evaporation process. The synthesized polymer-drug system was evaluated by different means such as FT-IR, TGA, DSC, XRD, entrapment efficiency (E.E), drug loading (D.L), particle size analysis, and zeta potential determination. Studies on in-vitro release using UV light at 227 nm at various pH levels were conducted, and the kinetics of release and cytotoxicity using the sulforhodamine B (SRB) assay on human skin fibroblast cells were examined.

Utilization of waste tea leaves as metal-free catalyst for hydrogen generation via ethanolysis of Sodium Borohydride

In the present study, waste green and black tea leaves have been used to synthesize metal–free catalysts for hydrogen generation by ethanolysis of sodium borohydride by the acetic acid activation and carbonization. The FTIR, BET, SEM-EDS, and XPS characterizations have been performed to analyze the synthesized catalysts' properties. The parameters such as amounts of catalysts, SB, and reaction temperature were studied while performing the experiments. They were optimized using the Response Surface Methodology (RSM) to obtain the highest values of Hydrogen Generation Rates (HGR) of 1350 ml min−1 g catalyst−1 and 2700 ml min−1 g catalyst−1 using the acetic acid activated black tea (AA – BT) and acetic acid activated green tea (AA – GT) catalysts respectively with the activation energies of 13.14 kJ mol−1 and 37 kJ mol−1. The BET analysis has revealed that the AA – GT and AA – BT catalysts have surface areas of 22.96 m2 g−1 and 3.28 m2 g−1, pore diameters of 1.72 nm and 1.70 nm and pore volumes of 0.0047 and 0.0331785 m3 g−1 respectively. The electrochemical analysis has revealed that the synthesized metal–free catalysts AA – BT and AA - GT possess good specific capacitances of 63.77 mF cm−2 and 121 mF cm−2, which shows that both can be used as electrode material for energy storage applications. Hence, it can be believed that both metal–free catalysts can act as dual functional materials, which can act as catalysts and energy storage materials.

Zeolite Y-based catalysts for efficient epoxidation of R-(+)-Limonene: Insights into the structure-activity relationship

Parent, hierarchical, and metal-modified hierarchical zeolite Y were investigated as heterogeneous catalysts in the R-(+)-limonene epoxidation, a catalytic route for synthesizing precursors of bio-polycarbonates, an alternative to isocyanate polyurethanes. The fresh catalysts underwent detailed characterization using XRD, N2 physisorption, TEM, SEM-EDX, pyridine-FTIR, NH3-TPD, CO2-TPD, UV–Vis-DRS, and solid-state NMR. Spent materials were investigated by TPO-MS and TGA, confirming low coke formation on the catalytic surface. The most active material was K–Sn-modified dealuminated zeolite Y, reflected in a high turnover frequency (TOF) of 96 h−1. This material exhibited the lowest Brønsted to Lewis acidity ratio (0.1), the highest mesoporosity fraction (43%), and the lowest total surface area (465 m2 g−1). Aprotic polar solvents with high polarity and medium donor capacity appeared suitable for limonene epoxidation. Limonene conversion of ca. 97% was reached at 70 °C, H2O2: limonene molar ratio = 7, and acetonitrile as a solvent, while selectivity to total monoepoxides exhibited values up to 96% under different reaction conditions. Hydration of internal epoxides to limonene diol was favored at high temperatures and high H2O2/limonene molar ratios. The efficiency of H2O2 reached maximum values of about 85% at low H2O2 amounts, while no significant influence was observed for temperature, catalyst amount, and the initial concentration of limonene. A plausible reaction mechanism was proposed for the R-(+)-limonene epoxidation with H2O2 based on the experimental findings.

Hollow CoP/carbon as an efficient catalyst for the peroxymonosulfate activation derived from phytic acid assisted metal-organic framework

The catalyst's composition and rationally designed structure is significantly interlinked with its performance for wastewater remediation. Here, a novel hollow cobalt phosphides/carbon (HCoP/C) as an efficient catalyst for activating peroxymonosulfate (PMS) was prepared. The ZIF-67 was synthesized first, followed by phytic acid (PA) etching and then heat treatment was used to get HCoP/C. The PA was used as an etching agent and a source of phosphorus to prepare HCoP/C. To analyze catalytic performance, another solid cobalt phosphides/carbon (SCoP/C) catalyst was prepared for comparison. In contrast to SCoP/C, the HCoP/C exhibited higher catalytic efficiency when used to activate PMS to degrade Bisphenol A (BPA). The results showed that about 98 % of targeted pollutant BPA was removed from the system in 6 min with a rate constant of 0.78 min−1, which was 4 times higher than the solid structure catalyst. The higher catalytic performance of HCoP/C is attributed to its hollow structure. In the study, other parameters such as BPA concentration, temperature, pH, and different catalyst amount were also tested. Moreover, the electron paramagnetic resonance (EPR) and radical quenching analysis confirmed that sulfate radicals were dominant in the HCoP/C/PMS system.

SrCaAl mixed metal oxides derived from LDH precursor as a novel and efficient solid base catalyst for Knoevenagel condensation reaction: Multivariate optimization study

The Knoevenagel condensation reaction is one of the most important reactions in the industry for the synthesis of organic materials, medicinal, and biological compounds. In this work, we have proposed an original and efficient solid-base catalytic system for the Knoevenagel condensation reaction. For the first time, a mixed oxide catalyst derived from hydrotalcite-like Sr0.5Ca2.5Al precursor was synthesized by co-precipitation method and subsequently calcined for 5 h at 850 °C. The catalysts were characterized by various techniques. The Sr0.5Ca2.5Al mixed oxide was also compared with the usual Ca3Al sample in terms of structural characteristics and catalytic activity in the Knoevenagel reaction between active methylene compounds and benzaldehyde. The findings revealed that the Sr0.5Ca2.5Al mixed oxide sample is considerably active in this reaction compared to the Ca3Al sample due to its stronger basicity. The kinetics of the Knoevenagel condensation reaction over the Sr0.5Ca2.5Al catalyst was investigated and indicated that it follows from the second-order model. The stability and reusability of the catalyst sample were studied and it was found that the Sr0.5Ca2.5Al catalyst has high stability and a good lifetime. The effects of reaction time, amount of catalyst, and reaction temperature on benzaldehyde conversion (%) and product selectivity (%) were assessed in this study using the Box-Behnken design. The appropriateness of the quadratic regression model was evaluated through the ANOVA method. Under optimal conditions, the conversion percentage of benzaldehyde and product selectivity reached 97% and 84%, respectively.

Hydrodeoxygenation of lignin bio-oil model compounds and surrogate mixtures over zeolite supported nickel catalysts

Bifunctional catalysts based on nickel supported on ZSM-5 and BETA zeolites were studied in the hydrodeoxygenation of lignin derived model compounds as well as in surrogate mixtures simulating the light fraction of lignin fast pyrolysis bio-oil. A screening of the hydrodeoxygenation reaction conditions (temperature, time, H2 pressure, catalyst amount) was carried out using the simplest phenolic compound, phenol. As in real lignin bio-oils more complex phenolic compounds are present, a series of relevant alkyl- and methoxy-substituted phenol and benzene (o- and m-cresol, catechol, anisole, guaiacol, syringol, creosol and 1,2,3-trimethoxybenzene) were also investigated as feedstocks. Furthermore, the effect of the different porous and acidic properties of the zeolitic supports was investigated in the hydrodeoxygenation of guaiacol. The conversion of the model phenolics and the yield of the respective (alkyl)cyclohexanes at relatively mild conditions (220 °C, 50 bar H2, 1 h) were in the range of 80–100% and 47–83%, respectively, being dependent mainly on the complexity/side-chain group of the phenolic/benzylic ring and on the balanced content of Brønsted acid sites of increased strength. Regarding the hydrodeoxygenation of the surrogate mixture (C7-C10 phenolics), 100% hydrodeoxygenation efficiency was achieved towards >60% yield of (alkyl)cyclohexanes (C6-C9 hydrocarbons). All hydrodeoxygenation tests were conducted in hexadecane as solvent/substrate in order to simulate model co-processing (i.e. bio-based phenolics with petroleum derived feedstocks) conditions. Reusability tests revealed the stability of the catalysts which showed partial (30%) deactivation after the third catalytic cycle.

Synthesis, characterization and catalytic activity of rGO supported novel hybrid materials for green fuel production

In the present study, reduced graphene oxide metal composites were synthesized using hydrothermal method for the purpose of green and efficient oxidative desulfurization for the removal of Sulfur content from fuel. The physiochemical characterization of amalgamated material was confirmed by powdered X-ray diffraction (P-XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX) and Thermogravimetric analysis (TGA). The XRD results clearly show that metals hybrids have been successfully doped over the surface of rGO having 15.61 nm, 19.03 nm, 27.98 nm, 28.89 nm and 24.37 nm crystallite size for NiO, rGO, ZnNiO@rGO, CuNiO@rGO and CoNiO@rGO respectively. Novel catalysts were checked against both model fuel (500 ppm DBT) and actual fuel (kerosene also called as paraffin oil and petro-diesel) by radical initiator mechanism of ODS. Excellent ODS activity was examined using 0.1g catalyst, 1ml H2O2, 100 ppm DBT at 40°C for 180 min. The dependence of efficiency rate with various factors of time, DBT concentration, amount of catalyst and oxidant and temperature was also studied. The whole mechanism follows pseudo first order reaction with a minimum requirement of energy of 1.491 kJ/mol to start a reaction for prepared materials. Novel catalysts show remarkable reusability up to 5 times that subsidizes to the economic permanency of reaction system.

Phosphonium-Catalyzed Monoreduction of Bisphosphine Dioxides: Origin of Selectivity and Synthetic Applications.

Controlling product selectivity in successive reactions of the same type is challenging owing to the comparable thermodynamic and kinetic properties of the reactions involved. Here, the synergistic interaction of the two phosphoryl groups in bisphosphine dioxides (BPDOs) with a bromo-phosphonium cation was studied experimentally to provide a practical tool for substrate-catalyst recognition. As the eventual result, we have developed a phosphonium-catalyzed monoreduction of chiral BPDOs to access an array of synthetically useful bisphosphine monoxides (BPMOs) with axial, spiro, and planar chirality, which are otherwise challenging to synthesize before. The reaction features excellent selectivity and impressive reactivity. It proceeds under mild conditions, avoiding the use of superstoichiometric amounts of additives and metal catalysts to simplify the synthetic procedure. The accessibility and scalability of the reaction allowed for the rapid construction of a ligand library for optimization of asymmetric Heck-type cyclization, laying the foundation for a broad range of applications of chiral BPMOs in catalysis.

Hydrogen generation from sodium borohydride hydrolysis using a heterogeneous biocatalyst prepared with Zabrus tenebrionides Goeze 1777 (Coleoptera: Carabidae) chitin

Co–B/Chi, which is made up of highly distributed Co–B particles, was synthesized by impregnation and chemical reduction methods. Scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, Brunauer–Emmett–Teller adsorption and Fourier transform infrared spectroscopy analyses were used to describe the morphology and microstructure of Co–B/Chi. The synthesized catalyst showed high catalytic activity in the hydrolysis reaction of NaBH4. The unsupported Co–B samples were compared with the chitin-supported Co–B catalyst, and the result showed that higher catalytic activity and good cycling stability for NaBH4 hydrolysis were obtained with the chitin-supported catalyst. The reaction conditions were investigated to achieve high hydrogen production. The maximum rate of hydrogen production was obtained at 40 °C and 20 mg catalyst amount. At ideal conditions, the hydrolysis reaction’s activation energy was determined to be 51.65 kJ mol−1. It is indicate that Co–B/Chi is a viable low-cost catalyst for the hydrolysis of NaBH4 for hydrogen production.

Improved photocatalytic performance in Ce3+ doped CoFe2O4 nanoparticles by modifying structural, optical, and magnetic properties

In recent research, semiconductive magnetic nanomaterials have gained significant attention for their potential in photocatalytic applications, primarily due to their ease of recoverability. This study focuses on the successful synthesis of CoCexFe2-xO4 nanoparticles, where the variable x (ranging from 0 to 0.20) introduces Ce3+ ions. The inclusion of Ce3+ ions induces noteworthy changes in the structural, optical, microstructural, magnetic, and photocatalytic properties of CoFe2O4 nanoparticles. Various analytical techniques, including x-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, photoluminescence, transmission electron microscopy, vibrating sample magnetometry, and electron paramagnetic resonance spectroscopy, were employed to investigate these effects comprehensively. The research delves into the photocatalytic degradation of rhodamine B under visible light irradiation, exploring the impact of different elemental compositions, catalyst quantities, irradiation durations, and initial rhodamine B concentrations on the decolorization process.

Heterogeneous Photo-Fenton-like Degradation of Oxytetracycline Containing Wastewater

Oxytetracycline (OTC) is a commonly used antibiotic. It can be absorbed to a limited extent by both humans and animals, so it can be detected at various levels in different water sources. Its presence in rivers or water and wastewater streams can pose serious problems for human and environmental health, and therefore, it needs to be treated. OTC degradation was studied using iron-doped g-C3N4 through a photo-Fenton-like oxidation process under simulated sunlight. In this study, the effects of key reaction parameters such as pH (3, 6, 9), catalyst amount (0-0.8 g/L), initial hydrogen peroxide concentration (HP, 0-20 mM) on the degradation of oxytetracycline were studied. The optimal reaction conditions for OTC degradation were found to be pH=6, catalyst amount of 0.4 g/L, and HP of 10 mM. Subsequently, the temperature effect was examined at the optimum reaction conditions. Based on the results, at 25, 35, and 45 °C, OTC degradation was found to be 51.1%, 60.8%, and 76.7%, respectively. The kinetic study conducted revealed that the observed reaction follows a second-order reaction kinetic model. In addition, the activation energy of observed reaction was found to be 86.96 kJ/mol.

Peracetic acid activated by nickel cobaltite as effective oxidizing agent for BPA and its analogues degradation

The presented research concerns the use of nickel cobaltite nanoparticles (NiCo2O4 NPs) for the heterogeneous activation of peracetic acid and application of NiCo2O4-PAA system for degradation 10 organic micropollutants from the group of bisphenols. The bisphenols removal (initial concentration 1 μM) process was optimized by selecting the appropriate process conditions. The optimal amount of catalyst (115 mg/L), peracetic acid (PAA) concentration (7 mM) and pH (7) were determined using response surface analysis in the Design of Experiment. Then, NiCo2O4 NPs were used to check the possibility of reuse in subsequent oxidation cycles. The work also attempts to explain the mechanism of oxidation of the studied micropollutants. The participation of the sorption process on the catalyst was excluded and based on the experiments with radical scavengers it can be concluded that the oxidation proceeds in a radical pathway, mainly with participation of O2•- radicals. Experiments conducted in real water matrices exhibit low impact on degradation efficiency. Toxicity tests with green alga Acutodesmus obliquus and aquatic plant Lemna minor showed that post-reaction mixture influenced growth and the content of photosynthetic pigments in concentration dependent manner.