Exceptional Reusability Research Articles

Response surface optimization, kinetics, thermodynamics, and life cycle cost analysis of biodiesel production from Jatropha curcas oil using biomass-based functional activated carbon catalyst

A highly efficient activated porous catalyst, BPAC-500-S, derived from waste banana peels through a novel synthesis involving pyrolysis; and functionalization with 4-benzene diazonium sulphonate, has been developed. For comparison of catalytic activity, the material was also functionalized with sulphuric acid (BPAC-500-SX). The (BPAC-500-S) catalyst underwent impregnation and activation with ZnCl2, and its properties were extensively characterized using BET, SEM, XPS, XRD, FT-IR, and TGA techniques. Comparative analysis of catalysts obtained at different pyrolysis temperatures (400, 500, and 600 °C) revealed that BPAC-500-S pyrolyzed at 500 °C, exhibited maximum surface area (840.83 m2g-1) and sulphur density (4.7 %). Utilizing BPAC-500-S as a catalyst, an efficient process for biodiesel synthesis from Jatropha curcas oil (JCO) was developed, achieving a remarkable 98.91 % conversion, as confirmed by 1H NMR spectroscopy. Notably, life cycle cost analysis demonstrated a low biodiesel production cost of $ 0.70/L. The BPAC-500-S catalyst exhibited exceptional reusability maintaining more than 80 % biodiesel yield over seven reaction cycles. This study presents a sustainable and cost-effective approach to biodiesel production, emphasizing the potential of waste-derived catalysts in green and economically viable processes.

Sodium alginate based adsorbent: Facile fabrication, extraordinary removal efficacy of anionic dyes and adsorption mechanism

Eco-friendly and renewable sodium alginate, as a potential alternative to fossil resources, has attracted considerable attention in wastewater treatment field. Herein, we develop a SA/PEI/PEG (sodium alginate/polyethyleneimine/polyethylene glycol diglycidyl ether) adsorbent in which SA was functionalized by PEI/PEG via a facile but effective strategy of one-pot gelation of aqueous SA/PEI/PEG solution. Systematic investigations were accomplished to explore the effects of adsorbent factors on the adsorption performances of the adsorbent towards the anionic dyes CR (congo red), AB-10B (amido black-10B), and AB-25 (acid blue-25). Strikingly, the SA/PEI/PEG exhibited exceptional adsorption performance to CR (2782 mg g−1, 90.6 %), AB-10B (1369 mg g−1, 90.9 %) and AB-25 (4221 mg g−1, 92.6 %) at 30 °C, pH = 3, 200 r min−1 and oscillated 24 h, and demonstrating exceptional reusability after six cycles of adsorption-desorption cycles. Furthermore, the three kinetic, four isothermic and one thermodynamic models were used to investigate the adsorption behaviors of the adsorbent towards these dyes. The possible adsorption mechanism is suggested: Hydrogen bond interactions and electrostatic attractions between SA/PEI/PEG and the dyes primarily contribute to exceptional adsorption capacity. The SA/PEI/PEG adsorbent endowed with easy fabrication, extraordinary adsorption capacity and excellent reusability promises potential application prospects in wastewater purification industry.

Efficient adsorptive removal of 2,4-dichlorophenoxyacetic acid (2,4-D) using biomass derived magnetic activated carbon nanocomposite in synthetic and simulated agricultural runoff water

This study focused on evaluating the efficacy of a magnetic activated carbon material (CPAC@Fe3O4) derived from pods of copper pod tree in adsorbing the toxic herbicide, 2,4- (2,4-D) from aqueous solutions. The synthesized CPAC@Fe3O4 adsorbent, underwent various characterization techniques. FESEM images indicated a rough surface, incorporating iron oxide nanoparticles, while EDS analysis confirmed the presence of elements like Fe, O, and C. Notably, the CPAC@Fe3O4 exhibited high surface area (749.10 m2/g) and pore volume (0.5351 cm³/g), confirming its mesoporous nature. XRD investigations identified distinct signals associated with graphitic carbon and magnetite nanoparticles, while VSM analysis verified its magnetic properties with a high magnetic saturation value (2.72 emu/g). The adsorption process was exothermic, with a decrease in adsorption capacity at higher temperatures. Freundlich isotherm provided the best fit for the adsorption, and the pseudo-second-order equation effectively described the kinetics. Remarkably, the maximum adsorption capacity ranged from 246.43 to 261.03 mg/g, surpassing previously reported values. The ΔH° value (−8.67 kJ/mol) suggested a physisorption mechanism, and the negative ΔG° values established the spontaneous nature. Furthermore, the synthesized adsorbent demonstrated exceptional reusability, allowing for up to five cycles of adsorption-desorption operations. When applied to simulated agricultural runoff, CPAC@Fe3O4 showcased a significant adsorption capacity of 160.71 mg/g for 50 mg/L 2,4-D, using a 0.2 g/L dosage at pH 2. This study showcased the transformation of copper pod biomass into a valuable magnetic nanoadsorbent capable of efficiently eliminating the noxious 2,4-D pollutant from aqueous environments.

Strategic decolorization of rose bengal in an aqueous environment using a zinc oxide-loaded reduced graphene oxide photocatalyst

The environmental and health hazards posed by synthetic organic dyes, such as Rose Bengal, have spurred significant concern in recent years. Herein, a novel zinc oxide/reduced graphene oxide (ZnO/rGO)-based photocatalyst is developed and used for the efficient decolorization of RB dye in aqueous solutions. The as-synthesized nanostructured material is characterized using advanced techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) mapping to elucidate its crystalline structure, morphology, and elemental composition. The XRD pattern confirmed the wurtzite crystalline phase structure with an average size of 67.8 nm, while SEM imaging verified the successful incorporation of ZnO nanoparticles into the rGO matrix. Further, the as-prepared material was used as a photocatalyst, which demonstrated remarkable performance in RB dye decolorization, achieving ≥96.1 % degradation within just 5 min at a minimal catalyst dosage of 8.0 mg. Moreover, kinetic studies revealed that the decolorization process followed a pseudo-second-order reaction mechanism, further enhancing the understanding of the catalytic behavior. It is more interesting that the catalyst exhibited exceptional reusability for up to seven cycles with only a decrease in catalyst efficiency from 96.1 % to 77.5 %, underscoring its practical viability and sustainability. The significance of this work lies in its contribution to addressing the environmental challenges associated with synthetic dyes, particularly rose bengal, by offering an efficient and reliable photocatalytic solution. The demonstrated efficacy of the ZnO/rGO photocatalyst not only showcases its potential for large-scale rose bengal dye degradation but also suggests broader applicability for the treatment of other synthetic dye pollutants.

Cellulose-based aerogel derived N, B-co-doped porous biochar for high-performance CO2 capture and supercapacitor

The remarkable characteristics of porous biochar have generated significant interest in various fields, such as CO2 capture and supercapacitors. The modification of aerogel-derived porous biochar through activation and heteroatomic doping can effectively enhance CO2 adsorption and improve supercapacitor performance. In this study, a novel N, B-co-doped porous biochar (NBCPB) was synthesized by carbonating and activating the N, B dual-doped cellulose aerogel. N and B atoms were doped in-situ using a modified alkali-urea method. The potassium citrate was served as both an activator and a salt template to facilitate the formation of a well-developed nanostructure. The optimized NBCPB-650-1 (where 650 corresponded to activation temperature and 1 represented mass ratio of potassium citrate activator to carbonized NBCPB-400 precursor) displayed the largest micropore volume of 0.40 cm3·g−1 and a high specific surface area of 891 m2·g−1, which contributed to an excellent CO2 adsorption capacity of 4.19 mmol·g−1 at 100 kPa and 25 °C, a high CO2/N2 selectivity, and exceptional reusability (retained >97.5 % after 10 adsorption-desorption cycles). Additionally, the NBCPB-650-1 electrode also delivered a high capacitance of 220.9 F·g−1 at 1 A·g−1. Notably, the symmetrical NBCPB-650-1 supercapacitor exhibited a high energy density of 9 Wh·kg−1 at the power density of 100 W·kg−1. This study not only presents the potential application of NBCPB-650-1 material in CO2 capture and electrochemical energy storage, but also offers a new insight into easy-to-scale production of heteroatomic-modified porous biochar.

Synthesis of Pyrano[2,3-d]Pyrimidine Diones Catalyzed by Cobalt-Doped Iron Tartrate Nanomaterial: A Sustainable and Efficient Approach

This study presents a novel and environmentally sustainable approach for the one-pot multicomponent green synthesis of pyrano[2,3-d]pyrimidine dione derivatives. The devised procedure involves a three-component condensation of aldehydes, malononitrile, and barbituric acid, employing a nanomaterial catalyst in the form of cobalt-doped iron tartrate. This catalyst, characterized by its nanoscale dimensions, demonstrates exceptional reusability and water solubility, contributing to its eco-friendly profile. The synthesis is conducted under reflux conditions, optimizing the reaction efficiency. Key attributes of the proposed protocol include the use of a non-toxic, cost-effective, and readily available catalyst. The high atom economy of the reaction signifies minimal waste generation, enhancing the sustainability of the synthetic process. Additionally, the reaction features a short duration, aligning with the principles of efficiency and resource conservation. Notably, the utilization of water as the solvent further enhances the green approach, minimizing the environmental impact. This innovative synthesis protocol not only addresses the growing demand for environmentally conscious methodologies but also showcases the potential for scalable and practical applications in organic synthesis. The integration of a reusable nanomaterial catalyst, coupled with the adoption of water as a solvent, positions this approach as a promising advancement in the pursuit of sustainable and green chemical practices. The study provides valuable insights into the development of efficient and environmentally benign synthetic routes for the production of pyrano[2,3-d]pyrimidine dione derivatives, paving the way for the exploration of greener alternatives in the realm of organic chemistry.

Dual Nonradical Catalytic Pathways Mediated by Nanodiamond-Derived sp2/sp3 Hybrids for Sustainable Peracetic Acid Activation and Water Decontamination.

Peracetic acid (PAA) oxidation catalyzed by metal-free carbons is promising for advanced water decontamination. Nevertheless, developing reaction-oriented and high-performance carbocatalysts has been limited by the ambiguous understanding of the intrinsic relationship between carbon chemical/molecular structure and PAA transformation behavior. Herein, we comprehensively investigated the PAA activation using a family of well-defined sp2/sp3 carbon hybrids from annealed nanodiamonds (ANDs). The activity of ANDs displays a volcano-type trend, with respect to the sp2/sp3 ratio. Intriguingly, sp3-C-enriched AND exhibits the best catalytic activity for PAA activation and phenolic oxidation, which is different from persulfate chemistry in which the sp2 network normally outperforms sp3 hybridization. At the electron-rich sp2-C site, PAA undergoes a reduction reaction to generate a reactive complex (AND-PAA*) and induces an electron-transfer oxidation pathway. At the sp3-C site adjacent to C═O, PAA is oxidized to surface-confined OH* and O* successively, which ultimately evolves into singlet oxygen (1O2) as the primary reactive species. Benefiting from the dual nonradical regimes on sp2/sp3 hybrids, AND mediates a sustainable redox recycle with PAA to continuously generate reactive species to attack water contaminants, meanwhile maintaining structural/chemical integrity and exceptional reusability in cyclic runs.

Advancing the eradication of harmful dyes through stereolithography-produced 3D floating photocatalysis: Exploiting the synergistic potential of graphene/MnO2/Fe3O4 hybrid nanomaterials

The utilization of heterogeneous photocatalysis for the breakdown of organic pollutants in wastewater has become increasingly popular as an alternative treatment method, offering rapid mineralization of organic compounds. However, the challenges lie in the recycling and recovery processes. To overcome this hurdle, a novel 3D-printed hybrid photocatalyst composed of graphene/MnO2/Fe3O4 was developed through an ex-situ approach. Comprehensive property evaluations were conducted, and the catalyst was employed in the creation of a 3D photocatalyst designed for MB dye removal under direct sunlight, facilitating the easy separation of the used catalyst. Further enhancement of its photocatalytic activity was achieved through carbonization, rendering it promising for wastewater treatment owing to its ordered structure and facile recovery. Notably, the developed 3D photocatalyst exhibited a significant improvement in MB dye degradation compared to powder samples. It showcased effective degradation of 10 ppm of MB dye within a mere 120 min of sunlight exposure. Radical trapping analysis indicated that the high photocatalytic degradation was predominantly attributed to the photogenerated superoxide radicals. Consequently, the 3D printed photocatalyst demonstrated exceptional reusability and sustained efficiency in MB dye degradation without any discernible decrease in catalytic activity. The augmented photocatalytic degradation was governed by the generation of photogenerated charge carriers through reduction and oxidation reactions. This research holds promise for the creation of an economical, user-friendly, and highly efficient 3D printed hybrid photocatalyst with synergistic applications in water purification.

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.

Synthesis, characterization and adsorption optimization of bimetallic La–Zn metal organic framework for removal of 2,4-dichlorophenylacetic acid

To eliminate the hazardous pesticide 2,4-dichlorophenylacetic acid (2,4-D) through aqueous solutions, stacked nanorods known as hetero bimetallic organic frameworks (MOFs) of 2-methyl imidazole based on lanthanum and zinc are created. The research's convincing discoveries displayed that La/Zn-MOF is an actual adsorbent for the removal of 2,4-D through aqueous solutions. The La/Zn-MOF was investigated using a variability of techniques, with scanning electron microscope (SEM), powered X-ray diffraction (PXRD), and Brunauer-Emmett-Teller (BET) investigation. La/Zn-MOF has a significant pore capacity of 1.04 cm³/g and a comparatively large surface area of 897.69 m2/g. Our findings, which are quite intriguing, demonstrate that adsorption behavior is pointedly wedged by variations in pH. A pH 6 dose of 0.02 g was shown to be the optimal setting for the greatest capacity for adsorption. Because adsorption is an endothermic process, temperature variations affect its capability. The adsorption method was fit both isothermally and kinetically using the Langmuir isotherm classical. It was created that the entire process made use of a chemisorption mechanism. Solution pH, temperature, adsorbent dosage, and time were all improved using the Box-Behnken design (BBD) and Response Surface Methodology (RSM). We were able to accurately calculate the values of ΔHo, ΔSo, and ΔGo for 2,4-D by following the guidelines. These results demonstrated the spontaneous and endothermic character of the adsorption procedure employing La/Zn-MOF as an adsorbent. Adsorption-desorption cycles can be carried out up to five times. With the synthesized La/Zn-MOF adsorbent due to its exceptional reusability. Many processes, such π-π interaction, pore filling, H-bonding, or electrostatic contact, were postulated to explain the connection between La/Zn-MOF and 2,4-D after extra research to appreciate well the link was conducted. This is the first study to demonstrate the effectiveness of utilizing La/Zn-MOF as an adsorbent to eliminate 2,4-D from wastewater models. The results display that a pH of 6 is required to achieve the maximal 2,4-D adsorption capability on La/Zn-MOF, which is 307.5 mg/g.

Synthesis of bimetallic Mn@ZIF–8 nanostructure for the adsorption removal of methyl orange dye from water

In this research, manganese-based Mn@ZIF-8 nanocomposite was prepared using solvothermal strategy. The resultant Mn@ZIF-8 nanostructure was assessed for the adsorption of methyl orange (MO) dye from water. The pristine ZIF-8 and Mn@ZIF-8 nanocomposite have demonstrated a rhombic dodecahedral morphology having a reasonable microporous structure. Besides, they have also displayed an outstanding specific surface area and porosity. The impact of contact time, concentration and variation in pH were analyzed in detail for the investigation of adsorption capacity. From the interpretation of the adsorption isotherms, it has been discovered that adsorption of MO over Mn@ZIF-8 follows the monolayer mechanism (Langmuir isotherm). Remarkable maximum adsorption capacity (qmax, 406 mg.g−1) has been recorded for the Mn@ZIF-8 which is sufficiently high as compared to pristine ZIF-8. The kinetic study explored that experimental data best fitted to the pseudo second order kinetics with relatively high R2 values (0.997) of Mn@ZIF-8. Thermodynamic study reconnoitered the adsorption process is spontaneous in nature. The synthesized Mn@ZIF-8 material also displays exceptional reusability capability of up to 92 % at 4th cycle compared to 1st cycle. Overall, the Mn@ZIF-8 could be a good contestant for the treatment of MO containing wastewater of industries.

Construction of Indium(III)-Organic Framework Based on a Flexible Cyclotriphosphazene-Derived Hexacarboxylate as a Reusable Green Catalyst for the Synthesis of Bioactive Aza-Heterocycles.

The constant demand for eco-friendly methods of synthesizing complex organic compounds inspired researchers to design and develop modern, highly efficient heterogeneous catalytic systems. Herein, In-HCPCP metal-organic framework (SRMIST-1), a heterogeneous Lewis acid catalyst containing less toxic indium and eco-friendly robust cyclotriphosphazene and exhibiting notable chemical and thermal stability, durable catalytic activity, and exceptional reusability was produced through the reaction between indium(III) nitrate hydrate and hexakis(4-carboxylatophenoxy)-cyclotriphosphazene. In the SRMIST-1 structure, secondary building units {InO7} are assembled by a connection of η2- and η1-carboxylic oxo atoms from different HCPCP ligands, forming a three-dimensional network. The occurrence of regularly distributed In(III) sites in SRMIST-1 confers superior reactivity on the catalyst toward the synthesis of 2,3-dihydroquinazolin-4(1H)-ones and 3,4-dihydro-2H-1,2,4-benzothiadiazine-1,1-dioxides by the cyclization reaction of 2-aminobenzamides and 2-aminobenzenesulphonamides with aldehydes under optimized reaction conditions, respectively. The notable features of this method include broad functional group compatibility, low catalyst loading (1-5 mol %), mild reaction conditions, easy workup procedures, good to excellent reaction yields, ethanol as a green solvent, reusability of the catalyst (five cycles), and economic attractiveness, which is mainly due to sustainability of SRMIST-1 as a reusable green catalyst. Our findings demonstrate that the highly reactive and reusable green catalyst finds widespread applications in medicinal chemistry.

Organic sandwich-structured carbon fiber/SiO2/PES electrochemical membrane with significantly improved charge transfer efficiency and water permeability

Electrochemical membrane separation has the potential for good degradation efficiency and mitigates membrane fouling. However, it is still a real challenge to further build stable organic substrate and improve its charge efficiency. In this study, an electric conductive and sandwich-structured carbon fiber/SiO2/polyether sulfone (CF/SiO2/PES) membrane showing good tetracycline (TC) removal at both acidic (pH = 3) and alkaline (pH = 9) conditions was fabricated by a facile phase conversion method. The CF/SiO2/PES membrane exhibited notably improved water permeability, augmented by 42 % higher with external voltage than that of the membrane without voltage assistance. Furthermore, the CF/SiO2/PES membrane performance in TC removal was systematically assessed under diverse conditions, encompassing TC concentration, pH values, and applied voltage. The membrane displayed a good removal efficiency of 93.6 % and 91.8 % for TC at acidic and alkaline conditions, respectively. Additionally, the degradation pathway of TC was proposed. Crucially, the CF/SiO2/PES membrane exhibited exceptional reusability and stability over eight consecutive runs. Mechanism study proved that the reactive species play a key role in the TC degradation during electro-filtration. The exceptional permeability, removal efficiency, and recyclability position the CF/SiO2/PES membrane as a promising solution for antibiotic wastewater treatment.

Carboxyl-Decorated UiO-66 Supporting Pd Nanoparticles for Efficient Room-Temperature Hydrodeoxygenation of Lignin Derivatives.

Hydrodeoxygenation (HDO) of lignin derivatives at room-temperature (RT) is still of challenge due to the lack of satisfactory activity reported in previous literature. Here, it is successfully designed a Pd/UiO-66-(COOH)2 catalyst by using UiO-66-(COOH)2 as the support with uncoordinated carboxyl groups. This catalyst, featuring a moderate Pd loading, exhibited exceptional activity in RT HDO of vanillin (VAN, a typical model lignin derivative) to 2-methoxyl-4-methylpheonol (MMP), and >99% VAN conversion with >99% MMP yield is achieved, which is the first metal-organic framework (MOF)-based catalyst realizing the goal of RT HDO of lignin derivatives, surpassing previous reports in the literature. Detailed investigations reveal a linear relationship between the amount of uncoordinated carboxyl group and MMP yield. These uncoordinated carboxyl groups accelerate the conversion of intermediate such as vanillyl alcohol (VAL), ultimately leading to a higher yield of MMP over Pd/UiO-66-(COOH)2 catalyst. Furthermore, Pd/UiO-66-(COOH)2 catalyst also exhibits exceptional reusability and excellent substrate generality, highlighting its promising potential for further biomass utilization.

Robust and Multifunctional Wetting Resistance of de novo Engineered Nonfluorinated Metal–Organic Nanocrystals for Environmental Sustainability

Direct synthesis of zeolitic imidazole framework crystals using bulky alkyl ligands is challenging. Herein, a bottom‐up approach to de novo synthesis of a superhydrophobic zeolitic metal–organic framework called mZIF, using mixed ligands, is developed. The mZIF nanocrystals contain a newly designed alkyl chain‐substituted 4‐imidazolate ligand, achieving tailorable hydrophobicity by varying the alkyl tail length. The molecular structure presenting appropriate ligands coupled with the porosity and roughness of the coated surfaces imparts superhydrophobic properties to various coated surfaces such as glass, steel, aluminum, and plastic. The resulting surfaces exhibit a high contact angle of ≥157° and a minimal rolling‐off angle (<5°), enabling efficient oil–water separation in a filtration setup. Furthermore, dip coating the mZIF nanocrystals onto a melamine sponge modifies its water wettability, allowing for facile and efficient removal and recovery of oil from diverse oil–water mixtures with exceptional reusability. Additionally, the mZIF‐modified surfaces showcase notable self‐cleaning and anti‐icing properties. The mZIF‐coated surface shows remarkable storage stability (>1 year), durability against harsh environmental conditions, and notable resistance to mechanical abrasion. This research represents a significant advancement in the facile engineering of multifunctional metal–organic framework‐based systems tailored for diverse practical applications.

Nitrogen and sulfur-doped biochar supported magnetic CuZnFe2O4 as a sustainable adsorbent for efficient reactive black dye 5 removal from industrial wastewater

AbstractThe shortage of clean and safe water resources, due to the growing pollution and the high cost of water treatment techniques, has become a real threat. Herein, CuZnFe2O4@N,S-doped biochar (CZF@N,S-BC), a novel magnetic, cleaner, and completely green-based composite, was fabricated using the aqueous extract of Beta vulgaris (sugar beet) leaves for the efficient removal of reactive black dye 5 (RB5) from industrial wastewater discharge. With the aid of numerous techniques, including Fourier-Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Spectroscopy (SEM), Vibrating Sample Magnetometer (VSM), and zeta potential analyses, CZF@N,S-BC was well-characterized. The results revealed the successful fabrication of CZF@N,S-BC with good magnetic saturation of 12 emu/g and a highly positively charged surface of 32 mV at pH 2. The removal efficiency of RB5 was reached 96.5% at equilibrium time 60 min, and adsorbent dose of 80 mg. The equilibrium data fitted well with the Freundlich isotherm model, while the adsorption kinetics followed a pseudo-second-order model (PSO), with a maximum adsorption capacity of 276.57 mg/g. The thermodynamics results confirmed the physical interaction between the composite and RB5. Additionally, the composite also demonstrated exceptional reusability, maintaining a removal efficiency of 57.27% even after six consecutive cycles. To evaluate the performance of CZF@N,S-BC composite in a real water matrix, the composite was subjected to remove RB5 from a real wastewater sample obtained from an industrial discharge of a textile dyeing industry. Also, a plausible mechanism of RB5 removal by the composite was intensively discussed using XPS before and after adsorption.

Facile synthesis of NiSe2-ZnO nanocomposites for enhanced photocatalysis and wastewater remediation.

In this study, NiSe2 nanocubes, ZnO rods, and their composites were prepared by simple chemical methods to investigate their photocatalytic response and antibacterial activity. The optimal concentration of NiSe2 nanocubes was explored for enhanced photocatalytic performance by varying its percentage in the NiSe2-ZnO composites. The findings suggested that the optical response of ZnO was significantly improved and shifted towards visible region by incorporating NiSe2 as a co-catalyst. The photocatalytic properties of NiSe2, ZnO, and NiSe2-ZnO composites were assessed under visible light by using methylene blue (MB) as a model pollutant. The results showed that the optimized composite containing 75% NiSe2 with ZnO exhibited outstanding photocatalytic efficiency of 97%. The degradation of MB dye by NiSe2, ZnO, and their composites followed the pseudo-first-order reaction kinetics (Langmuir-Hinshelwood model). Furthermore, the prepared NiSe2-ZnO composite displayed exceptional reusability and stability over a number of cycles, demonstrating its practical applicability. This research presents unique findings, showcasing the comparative antibacterial performance of NiSe2, ZnO, and NiSe2-ZnO nanocomposites against Bacillus cereus (B. cereus). Of all the prepared photocatalysts, the 75% NiSe2-ZnO nanocomposite revealed the best performance, exhibiting an inhibition zone of 28 mm.

Efficient photodegradation of carbamazepine by organocatalysts incorporating a third component with a more complementary absorption spectrum.

Carbamazepine, recognized as one of the most prevalent pharmaceuticals, has attracted considerable attention due to its potential impact on ecosystems and human health. In response, this work synthesized and characterized a novel environmentally friendly and cost-effective organic semiconductor photocatalyst PM6:Y6:ITCPTC loaded with coconut shell charcoal, and then investigated its performance for photocatalytic removal. Remarkably, carbamazepine demonstrated a photodegradation efficiency exceeding 99% within a mere 20 minutes of exposure to one sunlight intensity, and also showed good effectiveness under a low light intensity of 50 W. The catalyst exhibited exceptional reusability and stability, maintaining degradation efficiency between 95-99% over 25 cycles. The high photocatalytic activity of PM6:Y6:ITCPTC is primarily attributed to the incorporation of the third component (named ITCPTC), which enhances exciton dissociation and carrier transfer, generating superoxide radicals, electrons, and holes. Furthermore, the plausible degradation pathway of carbamazepine was proposed based on the measured intermediates and density functional theory calculations.

Construction of rGO-Bi2Sn2O7-NiFe2O4 nanoheterojunction system for the enhanced photodegradation of doxycycline: A brief insight on degradation kinetics and toxicological evaluation on Allium cepa

In this study, the rGO-Bi2Sn2O7-NiFe2O4 nanocomposite (RBN NCs) was fabricated using an in-situ hydrothermal method and applied for the effective aqueous degradation of doxycycline (DOX). Various analytical techniques were employed to characterize the physicochemical properties of the fabricated nanoparticles, including TEM, UV–Vis, PL, FE-SEM, ESR, DRS, XPS, XRD, and N2 adsorption and desorption analysis. The efficiency of DOX degradation by the RBN system under different conditions was evaluated. Under optimal conditions (RBN concentration = 50 mg/L and pH = 7.0), the NCs removed 99.1% of DOX (10 mg/L) within 270 min under visible light irradiation. ESR and scavenging tests illustrated that the developed system produced O2⦁- radicals, which played a dominant role in the complete degradation of DOX. The mineralization of DOX was confirmed by total organic carbon results. The RBN system displayed exceptional reusability over six consecutive cycles and could be easily removed from treated water due to its magnetic properties. The toxicity of the end-product after degradation was assessed against Escherichia coli (gram-negative) and Bacillus subtilis (gram-positive). Additionally, GC-MS analysis was conducted to predict the possible photodegradation pathway of DOX, providing a better understanding of the degradation process. Toxicity of intermediate products was also estimated computationally using the ECOSAR software. The fabricated RBN was further investigated for genotoxicity towards Allium cepa. This study provides new insights into the RBN system for environmental remediation.

Porous polyvinyl fluoride coated cellulose beads for efficient removal of Cd(II) from phosphoric acid

In order to enhance the removal of cadmium from phosphoric acid, it is imperative to explore novel resources that may be utilized for the development of highly effective and environmentally sustainable adsorbents. Cellulose beads are composed of naturally occurring polysaccharide fibers and find extensive utilization across several industrial sectors and applications. Within this framework, this research paper presents a green and simple method for producing porous cellulose beads using date palm fibers as the preferred raw material. The innovation lies in immersing the obtained cellulose beads in a Polyvinyl fluoride (PVDF)/N,N-dimethylformamide (DMF) suspension as a coating polymer with different concentrations (2.5, 5, 10 %) to maintain their stability in an acidic environment. The surface of cellulose/PVDF beads were subjected to multiple characterizations like Fourier transform infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), size distribution then pH stability confirming that the coating has been perfectly achieved and conserved well the shape of the beads. The coated cellulose/PVDF-2.5 % underwent evaluation by the process of batch adsorption experiments while different parameters were varied including contact time (5, 10, 20, 30, 60, 90 min), temperature (25, 35, 45 and 55 °C), and adsorbent mass (20, 40, 60, 80 and 100 mg). The obtained ICP data showed that the adsorption rate of Cd (II) from phosphoric acid medium decreased while increasing both temperature from 25 to 55 °C and contact time from 5 to 90 min while adding more adsorbent dosage from 20 to 100 mg enhanced the removal percentage. The cellulose/PVDF-2.5 % was more effective with an adsorption capacity equal to 3.4998 mg/g at optimal conditions including 25 °C as the temperature after 5 min as contact time and by adding a mass 100 mg of the biosorbent while the pH = 2 of the solution is maintained the same. The examined material's adsorption processes proved to be exothermic and non-spontaneous, and it proved that the pseudo-second-order model provided the best match for the cellulose/PVDF-2.5 % beads kinetics data. Furthermore, the cellulose beads exhibited exceptional reusability for up to four repeated cycles without undergoing desorption. The present study offers a viable approach for producing environmentally sustainable biomass-derived adsorbents. Additionally, the study validates the potential of cellulose/PVDF beads as an intriguing material for phosphoric acid decadmiation.