RhB Dye Research Articles

Ternary Carbon Spheres/PAA-Al2O3 Nanoparticles as an Efficient Catalyst for RhB Dye Degrader and Bactericidal Agent; Molecular Docking Analysis

Ternary Carbon Spheres/PAA-Al2O3 Nanoparticles as an Efficient Catalyst for RhB Dye Degrader and Bactericidal Agent; Molecular Docking Analysis

Low-frequency contact-electro-catalysis driven by friction between the PTFE-coated fabric and dye solution

The process of contact electrification occurs when two materials with dissimilar work functions are in contact and charged. Contact-electro-catalysis may occur when electron exchange at the liquid-solid interface initiates a redox reaction. This type of catalysis falls under the mechanically-driven tribocatalysis and has been demonstrated to be able to degrade dye under high-frequency ultrasonic excitation. In this work, a high RhB dye decomposition ratio of 91.5% is achieved by harnessing the ordinary low-frequency solid-liquid friction energy through the design and use of the recyclable fabric with PTFE coating as a solid friction source to agitate the dye solution. In the absence of PTFE coating, the RhB dye decomposition ratio is about 14.8% under the same friction conditions. The enhanced contact-electro-catalysis may be attributed to the high electronegativity of PTFE coating. According to the quenching experiments with active species, it is found that hydroxyl radical (·OH) and superoxide radical (·O2-) are the main active species induced by low-frequency solid-liquid friction. The fabric with PTFE coating after being dried and reused for 5 cycles still possesses 87.9% RhB dye decomposition ratio. With these advantages of high decomposition ratio of organic pollution, low cost, good recyclability, and environmental friendliness, the developed low-frequency contact-electro-catalysis in this work, is potential for organic wastewater treatment application through utilizing waste solid materials to harvest the mechanical friction energy between solid waste fabrics and ordinary waterflow in future.

Catalytic reduction, antibacterial, and antioxidant activities of green synthesized silver nanoparticles using Coccinea grandies (L) Voigt leaf extract

In this study, silver nanoparticles (AgNPs) were synthesized using the aqueous extract of Coccinia grandis (L) Voigt leaf (CGL) extract using microwave irradiation method and the structure was elucidated by various techniques such as UV–Visible spectroscopy, Fourier transformation infrared spectroscopy (FT-IR), x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive x-ray spectroscopy (EDX), and high-resolution transmission electron microscopy (HR-TEM). The UV–visible spectroscopy confirmed the formation of AgNPs and SPR band appear at 420 nm. FT-IR analysis indicated the presence of –OH and –NH functional groups from secondary molecules of CGL capping the AgNPs surface. HR-TEM revealed spherical aggregates with an average size of 29.4 nm. EDX confirmed the presence of elemental silver. XRD analysis showed that the AgNPs had a face-cantered cubic (FCC) crystal structure. The CGL-AgNPs were used as a heterogeneous catalyst to reduce RhB and CR dyes from aqueous solutions in the presence of sodium borohydride (NaBH4). The results showed that greater than 95 % of catalytic reduction can be accomplished within 9 min. The biosynthesized AgNPs demonstrated notable antioxidant activity (82.89 % in the DPPH assay) and antibacterial activity with a Zone of inhibition ranging from 9 to 11 mm. These findings suggest that CGL can be used to synthesize new, cost-effective AgNPs using an environmentally friendly approach.

Ag2O/ZnO/CuO and Ag2O/ZnO/NiO immobilised on reduced graphene oxide: synthesis, characteristics and its adsorption, catalytic behaviour and antibacterial activities

ABSTRACT Ag2O/ZnO/CuO (A/Z/C) and Ag2O/ZnO/NiO (A/Z/N) nanometal oxides were synthesised in different rations by co-precipitation method and were immobilised on reduced graphene oxide (rGO). The prepared nanocomposites were characterised by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Their application in the adsorption of MB, RhB and MO dyes, olefin oxidation and antibacterial properties were investigated. The results showed that A/Z/N/rGO adsorbent has 99% (10 min), 93% (20 min) and 97% (12 min) adsorption of MB, RhB and MO, respectively. From the investigation of Freundlich and Langmuir models, it was found that the adsorbent follows Langmuir. Moreover, the reaction thermodynamics was also studied, the reaction was endothermic and spontaneous. The kinetics of dye adsorption MB, RhB and MO on the surface follow a pseudo-second order model. At optimum condition, the conversion and selectivity of α-methylstyrene to acetophenone was >99% by A/Z/N and A/Z/C catalysts. A/Z/C/rGO nanocomposite has good antibacterial properties against two bacteria E. coli and S. aureus.

Synthesis of eco-friendly CaCO3@Zn-Al MMO core-shell nanoflowers photocatalyst using bio–eggshell waste for improved photocatalytic degradation of RhB under visible light irradiation

In this study, a type-I heterojunction was synthesized based on eggshell waste doped mixed metal oxide (ES@ZnAl MMO) for the degradation of RhB dye under visible light irradiation. The ES@ZnAl MMO core-shell was synthesized using waste eggshell and layered double hydroxide (LDH) as primary precursors. After their mechanochemical assembly and thermal treatment, CaCO3 was formed in both calcite and vaterite forms, alongside mixed metal oxides derived from the LDH (ZnO and Al2O3). The formation of a heterojunction between the semiconductors results in an improved activation of sites, a decrease in bandgap energy from 5.72 to 3.44 eV, and an increase in degradation capacity. The elemental composition, morphology, structural, and optical properties of the ES@ZnAl MMO nanocomposite were analyzed using various techniques. The optimal ES@ZnAl MMO photocatalyst demonstrated superior performance, reaching over 98% of RhB dye degradation under optimal conditions, outperforming pure ZnAl LDH, ZnAl MMO, and ES. After five run cycles, the ES@ZnAl MMO heterojunction still maintained a high photocatalytic performance for RhB dye (99%). Furthermore, it displayed high performance in degrading various other pollutants, including OG, IC, MB, and 2.4-DP, with degradation efficiencies of 97%, 99%, 99%, and 87%, respectively. This economically advantageous heterojunction showed its importance in environmental remediation, presenting a promising solution for addressing diverse pollution challenges.

Sonochemical preparation of powerful S-scheme Zr(HPO4)2/g-C3N4 heterojunction for photocatalytic degradation of rhodamine B under natural solar radiations

An effective Zr(HPO4)2/g-C3N4 S-scheme heterojunction was synthesized by sonochemical coupling of Zr(HPO4)2 nanoparticles as an oxidative photocatalyst [EVB = +3.0 eV] with g-C3N4 nanosheets as an effective reductive photocatalyst [ECB = −1.25 eV] for photocatalytic degradation of rhodamine B dye under natural solar radiation of 1000 W power. The physicochemical properties of the as-synthesized heterojunctions were investigated by X-ray diffraction [XRD], N2-adsorption-desorption isotherm, diffuse reflectance spectrum [DRS], photoluminescence [PL], scanning electron microscope [SEM], X-ray photoelectron spectroscope [XPS], and high resolution transmission electron microscope [HRTEM]. The experimental results implied the agglomeration of Zr(HPO4)2 nanoparticles on g-C3N4 sheets which reduced the specific surface area of the solid specimen from 88 to 21 m2/g. The significant increase in the photocatalytic degradation rate of RhB dye with introducing Zr(HPO4)2 nanoparticles implied that Zr(HPO4)2 plays a crucial role in reducing the band gap energy and remarkable increasing in the rate of electron-hole separation. The photocatalytic experiments implied that incorporation of 5 wt% Zr(HPO4)2 on g-C3N4 sheets destroyed 98 % of RhB dye during 3 h of light illumination with pseudo-first-order rate of 0.048 min−1. The remarkable enhancement in the photocatalytic performance of Zr(HPO4)2/g-C3N4 heterojunctions was ascribed to successful generation of an effective S-scheme heterojunction with strong redox power, utilizing of both hydroxyl and superoxide radicals in the degradation process and limiting the electron-hole recombination rate. Based on scavenger experiments and terephthalic acid PL analysis, the S-scheme pathway was chosen as the proposed mechanism for photocatalytic charge transfer. The as-synthesized Zr(HPO4)2/g-C3N4 heterojunction with exceptional redox power is considered a novel candidate for destructing organic pollutants that exist in industrial wastewater.

Rapid and efficient removal of water-soluble dyes via natural asphalt oxide as a new carbonaceous super adsorbent; NA-oxide synthesis and characterization

In this study, natural asphalt was oxidized to synthesize a new nano-structure adsorbent for dye removal. The functionalization of natural asphalt by oxidation introduced new properties that influenced its activity. The process of oxidizing natural asphalt with potassium permanganate resulted in a low-cost adsorbent, which can potentially be a more affordable option compared with synthetic alternatives. Characterization analysis confirmed the enhanced surface area, improving dye interaction and adsorption. The interconnected channels and capillaries of the oxidized natural asphalt facilitated the capillary action drawing in liquids, including dyes. The distinctive porosity of natural asphalt oxide (NA-oxide) was noted, and the experimental results showed that the NA–oxide nanoadsorbent efficiently adsorbed cationic and anionic dyes in water, with maximum capacities of 14.68 mg.g−1, 17.81 mg.g−1 and 16.47 mg.g−1 for methyl orange, methylene blue and Rhodamine B, respectively. The study investigated various parameters, such as concentration, adsorption dose, pH, contact time, and temperature, affecting the dye removal process. Langmuir, Freundlich, and Temkin isotherms along with pseudo-first and pseudo-second-order kinetic equations were applied to assess the adsorption process, indicating that dyes adhered to the pseudo-first-order model and Langmuir isotherm. Analysis of MO, MB, and RhB dyes revealed conformity to Langmuir isotherm and first-order kinetics. Thermodynamic evaluations like ΔH°, ΔS°, and ∆G° displayed the exothermic and spontaneous nature of dye adsorption on the NA-oxide adsorbent. Furthermore, the absorbent displayed remarkable stability with a recovery rate of 98.45% after ten cycles, signifying its potential for enduring effectiveness in dye removal processes.

Visible Light Active 0.95KNbO3‐0.05Ba(Nb1/2Sc1/2)O3 Ferroelectric for Enhanced Photocatalytic Activity

AbstractThis study reports a visible light active Ba/Sc co‐doped potassium niobate (KNbO3) ferroelectric material for enhanced photocatalytic applications. Through 5% Ba and Sc co‐doping in KNbO3 (i.e., 0.95KNbO3‐0.05Ba(Nb1/2Sc1/2)O3), the electronic band gap (Eg) is narrowed down to the visible range of the solar spectrum. The prepared samples are systematically examined by using X‐ray diffraction and Raman spectroscopy, which confirms the successful incorporation of Ba and Sc ions into the KNbO3 lattice. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis reveal particle morphology and chemical homogeneity of prepared samples. The UV–vis spectroscopy and ferroelectric PE‐loop demonstrate enhanced optical absorption compared to host KNbO3 while retaining ferroelectric behavior. The photoelectrochemical (PEC) measurements under visible light irradiation demonstrate a notable enhancement in the photocurrent for 0.95KNbO3‐0.05Ba(Nb1/2Sc1/2)O3 (hereafter denoted by 5KBSNO) compared to undoped KNbO3. Additionally, the 5KBSNO sample displays enhanced RhB dye degradation efficiency, reaching ≈50% compared to parent KNbO3 (≈30%) under light irradiation. First‐principles density functional theory (DFT) calculations are employed to understand the mechanism responsible for the reduced band gap. This study presents a promising material for developing advanced ferroelectric photocatalysts with tailored band structures for efficient solar energy harvesting for energy conversion and contamination remediation applications.

Structural, optical, photocatalytic and thermal behaviour of (Nb, Ta) co-doped WO3 nanoparticles and its application in photocatalytic degradation of MG and RhB dyes

In this communication, eco-friendly, cost effective and facile hydrothermal route was adopted to synthesize pure WO3, Nb-doped WO3 and (Nb, Ta) co-doped WO3 nanoparticles. Phase, lattice constants, crystallite size and crystallinity have been evaluated through X-ray diffraction. The insertion of Nb and Ta ions into WO3 nanoparticles was confirmed by XPS, FTIR and EDS studies. HRTEM and SAED micrographs exhibited highly nanocrystalline nature of samples. UV–visible studies was carried out to analyse nature of band gap, band gap energy, extinction coefficient, refractive index, Urbach energy and optical conductivity of prepared samples. Optical band gap was narrowed from 2.94 to 2.49 eV and Urbach energy was extended from 0.08 to 0.35 eV through co-doping of (Nb, Ta) ions into WO3 NPs. Reduction in PL intensity revealed that electron-hole pair recombination rate was decreased with co-doping of (Nb, Ta) ions. The photo-degradation efficiency of (Nb 5 %, Ta 5 %) co-doped WO3 nanophotocatalysts was 93.12 % against MG and 90.11 % against RhB dyes. The rate constant was found to be increased from 0.0107 to 0.0203 min−1 for MG and 0.0086 to 0.0174 min−1 for RhB. Thermal results exhibited the weight loss in three phase degradation processes, and thermal stability. The results showed that (Nb 5 %, Ta 5 %) co-doped WO3 NPs is a potential candidate for practical applications in environmental remediation (organic dyes degradation).

Synergistic role of indium doping and g-C3N4 reinforcement in boosting the visible light-triggered rhodamine B and diclofenac sodium salt degradation over rare earth molybdate

Designing and fabricating cost-efficient and eco-friendly photocatalysts for removing organic pollutants from wastewater streams is a crucial research objective for effectively managing industrial effluents to tackle environmental sustainability issues. In this study, we prepared bare cerium molybdate (Ce2(MoO4)3, M1) and indium-doped cerium molybdate (In- Ce2(MoO4)3, M2) photocatalysts via a hydrothermal method. We then synthesized a nanocomposite of In- Ce2(MoO4)3 (M3) with the promising material graphitic carbon nitride (g-C3N4) using an ultrasonication approach. The synthesized photocatalysts were effectively applied to degrade the Rhodamine B dye and diclofenac sodium salt (a drug) from synthetic industrial wastewater through a photocatalysis approach. The impact of indium (In3+) doping on the bare (Ce2(MoO4)3 and the strong interaction between the (In-Ce2(MoO4)3 and g-C3N4 nanosheets were analyzed through physical and electrochemical techniques, including SEM, EDS, XRD, FTIR, UV–Vis spectroscopy, and EIS analysis. The comprehensive photocatalytic degradation of dye and the drug via first-order kinetic parameters under visible light irradiation for all the prepared catalyst samples was evaluated. The nanocomposite In-Ce2(MoO4)3/g-C3N4 exhibited excellent photocatalytic activity, degrading the maximum amount of RhB dye and drug (RhB:96 %, drug:87 %) in 90 min with a higher rate constant (k) compared to In-Ce2(MoO4)3 (RhB:69 %, drug:56 %) and Ce2(MoO4)3 (RhB:56 %, drug:38 %). Furthermore, the In-Ce2(MoO4)3/g-C3N4 samples produced a 7-fold and 3-fold increase in transient photogenerated current response compared to pristine Ce2(MoO4)3 and In-Ce2(MoO4)3 samples, respectively. These findings pave the way for synthesizing an economical, versatile, and efficient In-Ce2(MoO4)3/g-C3N4 photocatalyst to eliminate pollutants from industrial wastewater streams and boost environmental sustainability.

Anchoring TiO2 and CuO nanoparticles on SnO2 nanotube arrays to construct ternary heterostructure for visible-light-driven photocatalytic degradation of green malachite dye

Designing and constructing heterostructure photocatalysts is necessary to facilitate the long-term separation of photogenerated charge carriers and enhance photocatalytic efficiency. Herein, a ternary nanocomposite photocatalyst based on SnO2, TiO2 and CuO semiconductors was successfully synthesized and employed as a highly effective photocatalyst for the malachite green (MG) dye degradation under visible light irradiation. According to the results, the ternary SnO2/TiO2/CuO nanocomposite demonstrated impressive photocatalytic activity (98.4 %) compared to pristine SnO2 nanotubes (40.3 %), binary SnO2/TiO2 (76 %) and SnO2/CuO nanocomposites (88 %), when exposed to 90 min of visible illumination. The photoreaction rate constant of SnO2/TiO2/CuO nanocomposite (0.0482 min−1) was found to be ∼8.5 times faster than SnO2 nanotubes (0.0057 min−1) against MG dye. This enhancement in photocatalytic performance can be attributed to the introduction of TiO2 and CuO which effectively suppress the recombination of photogenerated electron-hole pairs, accelerate the transfer of charge carriers, increase the active sites, and improve the optical absorption properties. Scavengers were used to elucidate the photocatalytic mechanism, exhibiting the pivotal role of •O2− and h+ in the photodegradation process. Besides, recyclability tests showed acceptable results after four cycles, confirming the stability and durability of the SnO2/TiO2/CuO nanocomposite against RhB dye degradation.

Plant-synthesis of co-doped tin dioxide nanocomposite with magnetic activity and its photocatalytic performance assessment on dyes and pesticides

The hydrothermal method was used to introduce different amounts of Praseodymium ion (Pr3+) (1, 3, 5, 7, 9, and 11 at.%) and Yttrium ion (Y3+) (1, 3, 5, 7, 9, and 11 at.%) into existing SnO2 nanoparticles. A novel nanocomposite was created by combining Fe3O4 and SnO2:Pr3+,Y3+ nanoparticles, resulting in a material with magnetic properties, i.e., Fe3O4/SnO2:Pr3+,Y3+, named FPYS. Subsequently, the hydrothermal synthesis approach was utilized to produce nanocomposites of FPYS in the presence of plant extract. The photodecomposition efficiency of as-synthesized nanocomposite was studied with some selected dyes and pesticides under 50W LED light. The present study focused on experimentally optimising the key parameters like the initial concentration, photocatalyst quantity, photocatalyst reuse, and pH level. By employing the Langmuir-Hinshelwood model, we successfully calculated the rate at which RhB, MB, 2,4-DCP, and MB undergo photocatalytic degradation under optimal conditions (pH = 7, pollutant concentration = 8 ppm, volume of pollutants = 20 mL, and photocatalyst amount = 3 mg). The model showed that MB, RhB, 2,4-DCP, and TCAA have k values of 0.061, 0.062, 0.051, and 0.036 min−1, respectively. The breakdown rate for MB dye was 81% and for RhB dye was 78% with nanocomposite made in the presence of 2 mL of Parkia speciosa extract, which was subjected to LED radiation for 150 min at pH 7. The degradation rates of 2,4-DCP and TCAA differed, i.e., the former was degraded by 68% and the latter by 52%. Pr3+ and Y3+ ions co-doped with SnO2 enhanced the photocatalytic degradation of dyes and pesticides.

Studies of pure TiO2 and CdSe doped TiO2 nanocomposites from structural, optical, electrochemical, and photocatalytic perspectives

A low temperature hydrothermal method is employed in this study to synthesize CdSe doped TiO2 nanocomposites. Further characterization and studies of the synthesized particles were carried out. As part of this study, the sample was examined by X-ray diffraction to determine its structure, crystallite size, strain, and crystallinity. Molecules were analyzed by energy dispersive X-ray spectroscopy to determine their chemical composition. By using fourier transform infrared spectroscopy spectroscopy, we were able to observe the presence of functional groups as well as the types of bonds. By analyzing the scanning electron microscopy spectra, we were able to determine the particle size while by analyzing the photoluminescence spectra, we could determine the bandgap energy. To determine the nature of materials and their effective photocatalytic behavior, optical bandgap energies were observed in the ultra-violet visible spectrum of synthesized particles. For determining the charge transfer mechanism and specific capacitance, electrochemical studies were conducted using electrochemical impedance spectroscopy and cyclic voltammetry analysis. The degradation of malachite green and Rhodamine-B dyes with CdSe doped TiO2 nanocomposites in the visible region was studied for photocatalytic activity, degradation efficiency, and rate constant. According to the results, doped nanoparticles increased the efficiency of RhB dye degradation by ~ 4% and MG dye degradation by ~ 20% over pure nanoparticles.

Assessment of silver and graphitic carbon nitride doped cadmium selenide quantum dots as an efficient dye degrader and antibacterial agent: In silico molecular docking analysis

This study demonstrates the synthesis of co-precipitated cadmium selenide (CdSe) quantum dots (QDs) doped with (2 and 4 wt %) of silver (Ag) and fixed quantity of graphitic carbon nitride (g-C3N4) for catalytic as well as antibacterial potential with molecular docking (MD) analysis. Comprehensive characterizations investigated the structural composition, surface morphology, elemental composition, and optical properties. XRD revealed the multiple phases (hexagonal and cubic) of CdSe with a notable rise in the diffraction peaks intensity upon doping. The optical studies demonstrated the range of absorption peaks, which increased upon doping confirmed through band gap energies significantly altered. TEM study revealed that a sheet of g-C3N4 overlapped with CdSe QDs, and certain nanorod-like structures emerged after Ag doping. HR-TEM was employed for the d-spacing computation of prepared samples and exposed a decreasing trend as the Ag concentration increased. Furthermore, the catalytic activity (CA) performed against RhB dye showed maximum results in the acidic medium with a higher concentration of Ag into g-C3N4 doped CdSe. The efficient bactericidal efficacy was evaluated against S. aureus bacteria with the highest inhibition zone of 13.75 mm for 4% Ag doping, which was further explained by investigating their inhibitory effects on DNA gyrase and tyrosyl-tRNA synthetase via MD.

Cu-doped NaNbO3 nanorods: Enhanced photocatalytic activity for RhB dye removal and antibacterial activity against E. coli

Sodium niobate (NaNbO3) nanorods with Cu (0.00, 0.01, 0.02 and 0.04 mmol) insertion were prepared by the microwave-assisted hydrothermal method and the photocatalytic and antibacterial activity was explored for the first time. X-ray diffraction confirms the coexistence of two orthorhombic phases (P21ma and Pbma) for all samples, with the percentage of each phase being strongly influenced by doping. The micrographs reveal that doping did not alter the shape or size of the grains (nanorods, with a diameter of ∼200 nm and a length of tens micrometers). The samples of pure NaNbO3 and those with 0.01 and 0.02 mmol of Cu showed an average band gap value of 3.08 eV. However, the sample containing 0.04 mmol of Cu exhibited a slight redshift. The photocatalytic activity of the samples was assessed by the removal of Rhodamine B dye (RhB), under ultraviolet light. All doped samples exhibited superior performance, with the sample containing 0.02 mmol of Cu showing the best photocatalytic activity, achieving 100 % RhB removal in 50 min. This was attributed to a lower rate of recombination of photogenerated charges, as evaluated through photoluminescence analysis. Additionally, the photocatalyst demonstrated excellent recyclability over three cycles. Pure NaNbO3 nanorods showed no antibacterial activity, but doping with 0.04 mmol of Cu reduced the growth of Escherichia coli.

Green-synthesized BiFeO3 nanoparticles for efficient photocatalytic degradation of organic dyes, antibiotic and catalytic reduction of 4-nitrophenol

Green-synthesized nanoparticles have recently emerged as promising catalysts for the removal of toxic dyes from water bodies. In this article, Bismuth ferrite (BiFeO3) nanoparticles were synthesized by a simple and low-cost method using Couroupita guianensis plant leaf extract. The particles were used as photocatalysts for degrading RhB, MO dyes, and TC antibiotics, as well as for reducing toxic 4-NP to useful 4-AP. The synthesized nanoparticles were characterized using several state-of-the-art tools. The formation of perovskite structure and the presence of biomolecules on the surface of BiFeO3 nanoparticles was confirmed by FTIR analysis. Raman spectrum revealed a rhombohedral structure of BiFeO3 nanoparticles, corroborating the XRD analysis. FESEM micrograph demonstrated irregularly shaped agglomerated nanoparticles. The average hydrodynamic diameter was estimated to be 51 nm using the DLS technique. The optical energy bandgap of the bismuth ferrite was estimated using Tauc’s relation for direct bandgap semiconductors. SQUID measurements revealed that these nanoparticles exhibit a weak ferromagnetic ordering. Furthermore, these nanomaterials degraded the cationic and anionic dyes effectively because of the formation of hydroxyl radicals, confirmed by the scavenger test. The photocatalytic degradation pathway of RhB dye was investigated through LC-MS analysis, and the intermediate degradation products were identified. The prepared material also exhibited excellent catalytic efficiency in a short duration of time. This study proclaims that these nanoparticles can be used as potential catalysts for the purification of water.

The amalgamated impact of bimetals, amino groups, and cross-linked structures of MOF on MOF for the removal of cationic dyes

To protect the environment, it is important to develop effective materials/methods for eliminating or decomposing pollutants. Metal-organic frameworks (MOFs) have attracted considerable interest due to their special properties, including their exceptional porosity and customizable architecture, which make them highly adaptable for many applications. In this study, bimetallic (Ce/Zr) NH2-UiO-66@NH2-MIL-125 was prepared and characterized by, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, thermogravimetric and BET analysis. The prepared bimetallic (Ce/Zr) NH2-UiO-66@NH2-MIL-125 served as a potent adsorbent for the efficient removal of cationic dyes via electrostatic, hydrogen bonding, ionic bonding, and π–π stacking. The adsorption of RhB and MB dyes by bimetallic (Ce/Zr) NH2-UiO-66@NH2-MIL-125 includes both isothermal and kinetic studies. The equilibrium adsorption data was found to conform to the Langmuir isotherm, whereas the kinetic adsorption process followed a pseudo-second-order model. The cross-linked structure of MOF on MOF enhances the stability of the adsorbent, and has the potential to efficiently adsorb and release organic dyes over multiple cycles. The aforementioned interactions as well as stability and reusability make the bimetallic (Ce/Zr) NH2-UiO-66@NH2-MIL-125 one of the most promising adsorbent for the removal of dyes from water.

Synergistic effect of samarium and PVP doped MgO nanostructures for RhB degradation and inhibition of DNA gyrase with molecular docking studies

Various concentrations (2 and 4 wt%) of Samarium (Sm3+) with a fixed amount (3 wt%) of polyvinylpyrrolidone (PVP) doped magnesium oxide (MgO) nanostructures (NSs) were synthesized via facile co-precipitation route. Trivalent dopant (Sm3+) and PVP narrowed the effective band gap of MgO and, controlled the recombination dynamics of the electron-hole pair and stabilized the nanostructures. This innovative treatment aimed to harness the potential ability of MgO to target bacterial cells and eliminate notorious dyes from wastewater. Advanced analytical (EDS and elemental mapping), crystallographic (XRD, SAED, FESEM, TEM and HR-TEM), and optical (UV–Vis and Raman) techniques were operated to probe their exclusive properties. The Sm/PVP-doped MgO displayed a pronounced catalytic activity against RhB dye in an acidic medium (96.42 %). Moreover, antibacterial activity was investigated using an agar well diffusion approach. At a high dosage, the % efficacy of pure and doped nanostructures against MDR S. aureus was 55.05, 65.64, 30.06 and 46.01, respectively. In silico docking investigation indicated that Sm/PVP-doped MgO NSs could inhibit DNA gyrase enzyme in S. aureus.

Improving multifunctional properties of the polyvinylidene fluoride (PVDF) membrane with crosslinked dialdehyde-starch (DAS) and polyethyleneimine (PEI) coating

Dialdehyde-soluble starch (DAS) and polyethyleneimine (PEI) were used to coat the polyvinylidene fluoride (PVDF) membrane for improving its antifouling and multifunctional properties through a combination of dip-coating and spray-coating techniques. The resulting membrane demonstrated excellent hydrophilicity and underwater oleophobicity due to hydrophilic DAS and PEI on its surface. The membrane achieved an impressive oil removal rate of 99.8 % and a flux 1420.8 ± 26.5 L·m−2·h−1 when it was used for oil-water emulsion separation. The hydration layer formed by the DAS and PEI greatly enhanced the membrane antifouling property, and its flux recovery rate was up to 96.6 % in BSA filtration experiments. The positive charge PEI and the negative charge DAS contributed to high separation efficiency of 99.1 % for the anion dye MO with the membrane D10P20, and high separation efficiency of 88.3 % for the cation dye RhB with the membrane P5D20. In addition, the coating layer was stable due to the cross-linked DAS and PEI. This research contributes greatly to the preparation of antifouling and multifunctional membrane using environmentally friendly material including polysaccharide derivatives and water soluble polymer.

Investigating the synergistic effect of Nd3+ and Ni2+ in CuO nanocrystals on their structural, optical, and magnetic properties for photovoltaic and photocatalytic implementations

The wet chemical precipitation technique was used to synthesize CuO, Nd:CuO and Ni-Nd:CuO nanoparticles efficiently. The produced substance was tested using X-ray diffraction (XRD) for confirming the crystallite structure, and scanning electron microscopy (SEM) was used to examine the morphological properties of the produced materials. Crystal defects and optical properties of the synthesized samples were analyzed through luminescence (PL) investigations and UV–Vis spectroscopy. EIS spectrum was utilized to study the electrochemical behavior of the prepared material. Vibrating Sample Magnetometer (VSM) was employed to examine the magnetic properties influencing from the doping of Ni2+ and Nd3+ ions into CuO, attributed to their substantial magnetic moment and ferromagnetic traits. Photovoltaic efficiency of the prepared material was studied by J-V characteristics and photon-to-electron converting efficacy (IPCE) studies. Photocatalytic properties were studied by degrading MB and RhB dyes. The enhancement in the photocatalytic performance of the Ni-Nd:CuO was a result of suppression of photogenerated electron-hole pair recombination and accelerated separation and migration of photogenerated charges.