Degradation Efficiency Of Rhodamine B Research Articles

Efficiency and mechanistic insights of photocatalytic decomposition of tetracycline and rhodamine B utilizing Z-scheme g-C3N4/SnWO4 heterostructures under visible light irradiation

The hydrothermal approach was used in the design and construction of the SnWO4 (SW) nanoplates anchored g-C3N4 (gCN) nanosheet heterostructures. Morphology, optical characteristics, and phase identification were investigated. The heterostructure architect construction and successful interface interaction were validated by the physicochemical characteristics. The test materials were used as a photocatalyst in the presence of visible light to break down the antibiotic tetracycline (TC) and the organic Rhodamine B (RhB). The best photocatalytic degradation efficiency of TC (97%) and RhB (98%) pollutants was demonstrated by the optimized 15 mg of gCNSW-7.5 in 72 and 48 min, respectively, at higher rate constants of 0.0409 and 0.0772 min−1. The interface contact between gCN and SW, which successfully enhanced charge transfer and restricted recombination rate in the photocatalyst, is responsible for the enhanced performance of the gCNSW heterostructure photocatalyst. In addition, the gCNSW heterostructure photocatalyst demonstrated exceptional stability and reusability over the course of four successive testing cycles, highlighting its durable and dependable function. Superoxide radicals and holes were shown to be key players in the degradation of contaminants through scavenger studies. The charge transfer mechanism in the heterostructure is identified as Z-scheme mode with the help of UV–vis DRS analysis. Attributed to its unique structural features, and effective separation of charge carriers, the Z-scheme gCNSW-7.5 heterostructure photocatalyst exhibits significant promise as an exceptionally efficient catalyst for the degradation of pollutants. This positions it as a prospective material with considerable potential across various environmental applications.

Facile construction of Bi2WO6/TiO2 microspheres heterojunction for boosting photocatalytic degradation of organic dyes

Flower-like Bi2WO6 microspheres and TiO2 spherical particles were prepared by a facile hydrothermal method without any surfactant or template. A unique Z-Scheme Bi2WO6/TiO2 heterojunction was successfully synthesized via a simple physical mixing method. The effect of mass ratio on the structure, morphology, optical properties, BET surface area and photocatalytic performance evaluated by degradation of organic dyes including Rhodamine B (RhB), methylene blue (MB) and methyl orange (MO) under solar irradiation was systemically investigated. When the mass ratio of Bi2WO6 to TiO2 was 1:4, the Bi2WO6/TiO2 composites exhibited the highest photocatalytic degradation efficiency, the highest degradation efficiency of RhB and MB reached 95.2 % and 89.3 %, which could be attributed to the construction of heterojunction structure between TiO2 and Bi2WO6. The optical absorption capacity of Bi2WO6/TiO2 composites was stronger than pure TiO2. Furthermore, the radicalquenching experiments proved that ·O2– and h+ played crucial roles in the photocatalytic reaction. The suitable band structure of Bi2WO6 and TiO2 revealed the Z-Scheme pathway and possible photocatalytic mechanism of Bi2WO6/TiO2 composites for organic dyes degradation. Thus, the direct Z-scheme Bi2WO6/TiO2 heterojunction effectively promoted separation of photogenerated electron-hole pairs, resulting in higher photocatalytic activity.

Efficient Homojunction/Heterojunction Photocatalyst via Integrating CsPbBr3 Quantum Dot Homojunction with TiO2 for Degradation of Organic Dyes.

A novel TiO2-CsPbBr3(Q) photocatalyst is proposed and rationally constructed, where CsPbBr3 perovskite quantum dots (QDs) of various sizes inside mesopore TiO2 (M-TiO2) are integrated. These perovskite QDs, generated in situ within M-TiO2, establish a type-II homojunction. Interestingly, a Z-scheme heterojunction is simultaneously formed at the interface between CsPbBr3 and TiO2. Due to the coexistence of the type-II homojunction and the Z-scheme heterojunction, photogenerated electrons are effectively transferred from TiO2 to CsPbBr3, thereby suppressing carrier recombination and thus enhancing the degradation of rhodamine B (RhB). Compared with pure CsPbBr3 and TiO2, TiO2-CsPbBr3(Q) shows significantly enhanced photocatalytic performance for RhB degradation. The degradation efficiency of RhB in the presence of the TiO2-CsPbBr3(Q) attains 97.7% in 5 min under light illumination, representing the highest efficiency observed among photocatalysts based on TiO2. This study will facilitate the development of superior semiconductor catalysts for photocatalytic applications.

Photocatalysis Meets Piezoelectricity in a Type-I Oxygen Vacancy-Rich BaTiO3/BiOBr Heterojunction: Mechanism Insights from Characterizations to DFT Calculations.

It is a challenging task to design a piezoelectric photocatalyst with excellent performance under mechanical agitation instead of ultrasonic irradiation. Integrating vacancy defects into a heterojunction seems to be an effective strategy for synergistically increasing its piezo-photocatalytic performance. For this goal, a two-step hydrothermal method was adopted to architect a type-I oxygen-vacancy-rich BaTiO3/BiOBr heterojunction to surge the degradation of Rhodamine B (RhB) under the combined action of simulated sunlight irradiation and mechanical agitation. Various instrumental techniques demonstrated the formation of a BaTiO3/BiOBr heterojunction with high crystallinity. The existence of surface oxygen vacancies was confirmed by XPS and EPR tests. PFM results manifested that this heterojunction had excellent piezoelectric properties, with a piezoelectric response value of 30.31 pm V-1. Comparative experiments indicated that RhB degradation efficiency under piezo-photocatalysis over this heterojunction largely exceeded the total sum of those under piezocatalysis and photocatalysis. h+, ·O2-, and 1O2 were the dominant reactive species for RhB degradation. The improved separation efficiency of photogenerated charges was verified by electrochemical measurements. DFT calculations indicated that the polarization of BaTiO3 could affect the electronic band structure of BiOBr. This work will provide comprehensive insights into piezo-photocatalytic mechanism at a microcosmic level and help to develop new-styled piezoelectric photocatalysts.

Facile one-step preparation of Co2CrO4 spinel from heterometallic compounds – Structural, magnetic, electrical and photocatalytic studies

Two isostructural heterometallic complex salts with mononuclear units, [NH(CH3)2(C2H5)][Cr(terpy)2][CoCl4]2 (1) and [NH(CH3)(C2H5)2][Cr(terpy)2][CoCl4]2 (2), were synthesized using a building block approach and characterized by single-crystal and powder X-ray diffraction (XRD), impedance spectroscopy and magnetization measurements. They exhibit particular humidity-sensing properties and very high proton conductivity at room temperature. The magnetization of complexes shows the high spin state of 3/2 for tetrahedrally coordinated CoII ions, which on cooling remain in the paramagnetic state within the CrIII network, which is antiferromagnetically correlated. The prepared compounds were thoroughly explored as single-source precursors for the formation of the spinel oxide Co2CrO4 by their thermal decomposition. By optimizing the annealing temperature, heating/cooling rates and holding times, the phase composition of thermal processing of 1 or 2 was evaluated: phase pure spinel Co2CrO4 was obtained by thermal treatment already at 450 °C. The structure, morphology, and optical properties of spinel oxides prepared at different temperatures were characterized using powder XRD, field emission scanning electron microscopy (SEM) and UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), while electrical and magnetic by impedance spectroscopy and magnetization measurements. The determined band gap energy and nanosized crystallites prompted us to investigate the photocatalytic activity of spinel oxide produced at 450 °C in the degradation of dyes Rhodamine B (RhB) and Methylene blue (MB) under Vis irradiation without and with assistance of hydrogen peroxide (H2O2). The results show that the Co2CrO4/H2O2 system exhibits a significantly higher photoactivity response; the degradation efficiency of MB and RhB was found to be 86.1% and 80.3%, respectively. The electrical conductivity spectra and the activation energy for the DC conductivity demonstrate the electronically semiconducting behaviour of the Co2CrO4 oxide. The Co2CrO4 spinel has a ferrimagnetic ground state, with mixed CoII and CoIII ions on the tetrahedral and octahedral sites: CoII having a high spin state on both sites and CoIII having a high spin state on the tetrahedral site and a low spin state on the octahedral site. Different thermal treatments affect the magnetization according to the different sizes of the obtained crystallites.

Constructing a Z-Scheme Co3O4/BiOBr Heterojunction to Enhance Photocatalytic Peroxydisulfate Oxidation of High-Concentration Rhodamine B: Mechanism, Degradation Pathways, and Toxicological Evaluations.

Photocatalytic coupling technologies have emerged as popular strategies to increase the treatment efficiency of dye-containing wastewater. Herein, the Z-scheme Co3O4/BiOBr heterojunction (Z-CBH) was constructed and developed as a photocatalytic peroxydisulfate (PDS) activator for the degradation of high-concentration Rhodamine B (RhB). Multiple testing techniques were employed to confirm the formation of Z-CBHs. When 0.1 g·L-1 of Z-CBH20 and 1.0 mmol·L-1 of PDS were added simultaneously under simulated sunlight irradiation, the RhB degradation efficiency could approach 91.3%. Its reaction rate constant (0.01231 min-1) was much beyond the sum of those in the Z-CBH20/light system (0.00436 min-1) and the PDS/light system (0.0062 min-1). h+, •OH, •O2-, SO4•-, and 1O2 were detected as the dominant reactive species for RhB degradation. The potential mechanism of photocatalytic PDS oxidation was proposed. The possible intermediates were determined by high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry assisted with density functional theory and Fukui theory. The possible degradation pathways of RhB degradation were put forward. The toxicological properties of RhB and its intermediates were evaluated by quantitative structure-activity relationship prediction. This work will not only provide a reference for developing photocatalytic persulfate activators but also gain an insight into the degradation pathways of RhB and the toxicity of its intermediates.

Construction of Co-doped Fe2O3/carbonized melamine foam heterogeneous catalyst for enhanced degradation of organic pollutants through peroxymonosulfate activation

Co-doped Fe2O3/carbonized melamine foam heterogeneous catalyst (CMF/Co-Fe2O3) was prepared by hydrothermal method. Rhodamine B (RhB) degradation was employed as a model test for evaluating peroxymonosulfate (PMS) activation. The degradation efficiency of RhB can reach 97 % in the catalyst dosage (50 mg/L), PMS concentration (100 mg/L), pH = 7 and RhB initial concentration (10 mg/L) after 60 min reaction. The reaction rate constant is 10 times higher than that of CMF/Fe2O3 and the activation ability of PMS is greatly improved. The degradation efficiency of RhB can be inhibited by increasing the initial mass concentration of RhB and pH value. The effect of temperature on the degradation rate of RhB conforms to the Arrhenius model, and the degradation process is a surface reaction controlled process. The results of free radical capture experiments and electron paramagnetic resonance (EPR) experiments showed that SO4¯ was the main active free radical for RhB degradation. After four cycles, the degradation efficiency of RhB still maintains 80 % with CMF/10 %Co-Fe2O3 catalyst. The heterogeneous catalyst exhibited potential application in the field of degradation of dye wastewater due to its excellent cycling stability.

Cellulose beads supported CoFe2O4: A novel heterogeneous catalyst for efficient rhodamine B degradation via advanced oxidation processes

In this study, a novel mechanical process was used to produce cellulose beads (CB). These beads were then doped with cobalt ferrite nanoparticles (CoFe2O4 NPs) to serve as catalysts for the degradation of rhodamine B (RhB) through peroxymonosulfate (PMS) activation. The physical and chemical properties of CoFe2O4 and CoFe2O4@CB catalysts were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) combined with energy dispersive X-ray spectrometer (EDX), scanning transmission electron microscopy (STEM) techniques, and thermogravimetric analysis (TGA). To optimize RhB degradation efficiency, Response Surface Methodology (RSM) was employed, utilizing the Box-Behnken design (BBD). Under the optimized conditions of a catalyst dosage of 0.40 g/L, PMS dosage of 0.98 mM, RhB concentration of 40 mg/L, pH of 5.27, and reaction time of 60 min, a remarkable degradation efficiency of 98.51 % was achieved at a temperature of 25 °C. In quenching experiments, 1O2, SO4•−, and HO• species are produced in the CoFe2O4@CB/PMS system, with 1O2, and SO4•− species dominating RhB degradation. Remarkably, the new CoFe2O4@CB catalyst has demonstrated exceptional stability and reusability, validated by recycling tests (up to 78 % of RhB degradation efficiency after a 5-cycle experiment) and subsequent characterizations (FTIR, SEM, and EDX) emphasizing unchanged bands, uniform distribution, and consistent composition after reuse cycles. These results demonstrate the effectiveness of mechanically produced CoFe2O4@CB catalysts for advanced oxidation processes (AOPs), with promising applications in wastewater treatment.

Activation of peroxymonosulfate by halloysite nanotube-supported TiO2 composite for efficient photocatalytic degradation of Rhodamine B

In this study, to enhance the peroxymonosulfate (PMS)-assisted photocatalytic degradation of Rhodamine B (RhB) under visible light over TiO2, a novel halloysite nanotube (HNTs) supported TiO2 composite photocatalyst was prepared by the sol-gel method. The crystal structure and bonding information of samples were investigated by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–visible diffuse reflection spectroscopy (DRS), photoluminescence (PL) and electrochemical impedance spectroscopy (EIS) were used to characterize the morphology, optical properties and energy band structure of the samples. The composite with weight ratio of 1:5 (HNTs/TiO2) (named HT-20) exhibited apparently enhanced PMS-assisted photocatalytic RhB degradation efficiency and can degrade approximately 95.31 % of RhB in 30 min, and the first-order rate constants (k) of HT-20-PMS system is about 54.5 times higher than that of B–TiO2. In addition, the possible mechanism of enhanced PMS-assisted photocatalytic activity of HT-20 was proposed. The improvement of photocatalytic activity in the composite photocatalyst can be ascribed to the large surface area and strong adsorption capacity of HNTs.

Thermally activated natural chalcopyrite for Fenton-like degradation of Rhodamine B: Catalyst characterization, performance evaluation, and catalytic mechanism

In this work, catalytic activity of natural chalcopyrite (CuFeS2) was improved by thermal activation. The modified chalcopyrite was used as efficient catalyst for degradation of organic dye Rhodamine B (RhB) through advanced oxidation process (AOP). Effects of catalyst dosage, H2O2 concentration, reaction temperature, solution pH, anions, and natural organic matter on the degradation efficiency of RhB were investigated. This study revealed that thermal activation at 300 °C changed the chemical valency of surface elements rather than transforming the major chemical phase of natural chalcopyrite. The Fenton-like degradation of RhB was significantly improved by thermally activated chalcopyrite. RhB degradation could be obtained under broad pH and showed high resistance to natural organic matter and anions. Under optimal conditions of H2O2 43.0 mM, catalyst 0.75 g/L, initial pH 5.1, and reaction temperature 25 °C, the degradation of RhB reached 96.7% at 50 min. Based on the rate constant of reaction kinetics, the activation energy for RhB degradation was calculated to be 9 kJ/mol. Radical scavenging experiments and electron paramagnetic resonance (EPR) technique demonstrated that RhB degradation was dominated by the generated hydroxyl radicals in activated chalcopyrite/H2O2 system. The formation of surface sulfates resulted from thermal activation induced the dissolved copper or iron ions, and promoted H2O2 activation and facilitated RhB degradation by reactive hydroxyl radicals. This work provides an in-depth understanding of the mechanism behind thermal activation to enhance the activity of natural chalcopyrite, offering a theoretical basis for utilizing natural minerals for Fenton-like treatment of organic wastewater towards cleaner production.

Enhanced catalytic performance of peroxydisulfate activation for Rhodamine B degradation over a novel MIL-68(Fe)/CuBi2O4 catalyst

The development of advanced strategy to activate persulfate for wastewater treatment is an ever-hot research topic. Herein, a high-performance composite catalyst MIL-68(Fe)/CuBi2O4(30 %) (M-CBO-30) was prepared by in-situ synthesizing MIL-68(Fe) in the CuBi2O4. The catalytic performances of M-CBO-30 as heterogeneous catalyst to activate PDS for the Rhodamine B (RhB) degradation were systematically studied. It was shown that the M-CBO-30/PDS system presented an ultrahigh RhB degradation efficiency which could remove 100 % RhB within 5 min only using 0.4 g L− 1 catalyst and 0.4 mM PDS. In addition, the M-CBO-30 could remove RhB at a wide pH range (2–10). One should note that the M-CBO-30 exhibited outstanding reusability which afforded high degradation efficiency after 5 successive recycles. And the catalyst structure remained still after being used for 5 catalytic cycles. Heavy metal ions leaching experiment indicated that Cu2+ leaching concentration of M-CBO-30 was far lower than that of the city water criterion in Europe. The RhB degradation mechanism by M-CBO-30/PDS system was proposed based on the result of electrochemical experiment, radical quenching test, electron paramagnetic resonance and XPS analysis. The RhB degradation was attributed to the oxidization of reactive oxygen species (i.e., SO4•−, •OH and 1O2). The synergistic effect of redox cycle of surface Fe, Bi and Cu were responsible for the high-efficient PDS activation. The excellent recyclability, outstanding structural stability, wide pH application range, less heavy metal leaching and superhigh RhB degradation efficiency highlights the light application prospect of M-CBO-30 in SR-AOPs-driven RhB decontamination.

Facile synthesis of g-C3N4 nanosheets for effective degradation of organic pollutants via ball milling

Abstract Graphitic carbon nitride (g-C3N4) has attracted extensive research interest in pollutants remediation. However, the photocatalytic activity of g-C3N4 was significantly limited by its small specific surface area. In this work, a green, high-energy ball milling method was used to fabricate g-C3N4 nanosheets. The structure, morphology, and optical properties of the prepared g-C3N4 nanosheets were characterized. The effect of ball milling parameters on the photocatalytic performance evaluated by Rhodamine B (RhB) and tetracycline (TC) was investigated systemically. Among the tested samples, the g-C3N4 sample milled with a 4 mL isopropanol solution at a rotation speed of 420 rpm, ball-to-powder weight ratio of 10:1, and milling time of 24 h exhibited the highest RhB degradation efficiency of 91.4% and TC degradation efficiency of 70.2%. The enhanced photocatalytic activity after ball milling was ascribed to the increase in specific surface area and efficient separation of electron–hole pairs. The trapping experiment indicated that holes and superoxide radicals were the main active species in the degradation reaction. Moreover, the photocatalytic degradation mechanism of organic pollutants on g-C3N4 nanosheets was also discussed in detail.

Peroxymonosulfate (PMS) activated by magnetic Fe3O4 doped carbon quantum dots (CQDs) for degradation of Rhodamine B (RhB) under visible light: DFT calculations and mechanism analysis

Currently, photo-assisted peroxymonosulfate (PMS) activation has received more and more attention in the degradation of wastewater pollutants. In this paper, the Fe3O4@CQDs magnetic nanocatalyst was successfully prepared by modifying α-Fe2O3, and Rhodamine B (RhB) was degraded by activating PMS under visible light. Moreover, in order to explore the reason why Fe3O4@CQDs was more beneficial to the activation of PMS than α-Fe2O3 at the microscopic level and reaction mechanism, the corresponding DFT calculations were performed. The results revealed that the degradation efficiency of RhB reached 98% in 35 min. Subsequently, the quenching experiments and EPR tests jointly verified that SO4•-, •OH, O2•- free radical pathway and 1O2, h+ non-free radical pathway participated in the degradation of RhB in the Fe3O4@CQDs + PMS + light system. The adsorption energy reached −5.247 eV with Fe3O4@CQDs adsorbed PMS by DFT calculation. The electron enrichment and charge redistribution can be apparently observed during the adsorption of PMS at Fe3O4@CQDs nanocatalyst. It was confirmed that the embedding of CQDs effectively regulated the electron transfer efficiency at the Fe3O4@CQDs interface to promote the improvement of electrical conductivity. It was more conducive to forming Fe(Ⅲ) to Fe(Ⅱ) cycles, and then the ability of the catalyst to activate PMS was improved.

Fabrication of Self-Assembled BiFeO3/CeO2 Nanocatalytic Materials for Efficient Catalytic Dye Degradation.

The catalytic treatment of wastewater serves as an effective way to solve the problem of water pollution, in which non-homogeneous Fenton catalysts are widely used. However, the activity enhancement of non-homogeneous Fenton catalysts still remains a great challenge. Herein, self-assembled BiFeO3/CeO2 nanocatalytic materials with different molar ratios were successfully fabricated by a suspension blending method, following which the structure evolution was determined by various characterizations. The catalytic degradation of methylene blue (MB), rhodamine B (RhB), and saffron T (ST) were performed over the BiFeO3/CeO2 nanocatalytic materials. It was found that the 0.2BiFeO3:0.8CeO2 nanocatalytic materials exhibited an 80.8% degradation efficiency for RhB. The 0.6BiFeO3:0.4CeO2 nanocatalytic materials reached 81.1% and 48.7% for ST and MB, respectively. The BiFeO3/CeO2 nanocatalytic materials also showed a good stability during several cycles. The combination of CeO2 with BiFeO3 led to an enhanced activity for dye degradation, probably due to the electron transfer from ≡Fe2+ to ≡Ce4+. This study provides a new approach to dye degradation by using Fenton catalytic systems.

Selective oxidation of organic pollutants over a new Co-based MOF via peroxymonosulfate activation under UV light: Performance and mechanism

The oxidation processes dominated by nonradical singlet oxygen (1O2) could accomplish highly selective oxidation, which attracted increasing attentions in recent years. However, the 1O2 generation path still remains ambiguous. In this study, a new 3D Co-based metal–organic framework (MOF) namely BUC-100 was solvothermally synthesized from CoCl2·6H2O, 1,3,5-tris(1-imidazolyl) benzene (TIB) and terephthalic acid (H2BDC). The as-prepared BUC-100 was used to selectively degrade various organic contaminants including both electron-donating and electron-withdrawing contaminants. The results revealed that the organic contaminants with electron-donating functional groups like –OH, –NH2 and alkyl groups rather than electron-withdrawing functional groups like –NO2 were easier to be degraded without significant interference of co-existing anions. Furthermore, Rhodamine B (RhB) was adopted as a pollutant model to optimize the reaction conditions and explore the possible oxidative degradation mechanism. The RhB degradation efficiency was up to 100% within 40 min in the presence of 0.3 g/L BUC-100, 0.4 mM peroxymonosulfate (PMS) and LED UV light irradiation. According to the results of trapping experiments, electron spin resonance (ESR) characterization, and quantitative/qualitative experiments, it was found that 1O2 played the dominant role in organic pollutants decontamination, in which the self-reaction of SO5•− was the main source of 1O2.

Efficient degradation of dye wastewater by catalytic ozonation reactive ceramic membrane with facile spraying of nano Ti[sbnd]Mn oxides: A pilot scale attempt

The traditional treatments of dye wastewater exist obvious drawbacks of low efficiency but high energy consumption. To solve this problem, based on the concept of combining degradation and separation, an integrated process of TiMn oxides catalytic ozonation and ceramic membranes (CM) was proposed to degrade dye wastewater in this paper. Specifically, TiO2/MnO2 hybrid catalysts were loaded on the surface of CM with a spraying printing method to prepare a reactive ceramic membrane (TiO2/MnO2-CM). The degradation efficiency and permeate flux of the TiO2/MnO2-CM + O3 system on Rhodamine B (RhB) were investigated. The SEM results illustrated that the catalyst was successfully loaded on the surface of CM. Additionally, the degradation efficiency of RhB was 100 % in 40 min under the conditions of catalyst spray layers 12, ozone concentration 2.5 g/cm3, and initial concentration of RhB 20 mg/L, and the permeate flux of TiO2/γ-MnO2-CM was as high as 125.399 kg/ (m2·h). Supplementarily, the study revealed that TiO2/γ-MnO2-CM could increase the concentration of ozone in water and catalyze ozone to produce more hydroxyl radicals (•OH), and the concentration of dissolved ozone was 0.7545 mg/L, •OH 68.16 μmol/L respectively. Eventually, the catalytic ozonation TiO2/γ-MnO2-CM device was scaled up, which treated 96 L RhB with a degradation efficiency of 100 % in 50 min. The work gives a solid foundation and scientific value for the industrial application of reactive CM in water or wastewater treatment.

An efficient biosynthesis of novel ZnO/CuO nanocomposites using berberis vulgaris extract (ZnO/CuO@BVENCs) for enhanced photocatalytic degradation of pollution, antibacterial and antifungal activity

In this study, an environmentally-friendly method was employed to synthesize ZnO/CuO nanocomposites using berberis vulgaris extract, resulting in ZnO/CuO@BVE NCs. The structure and properties of the ZnO/CuO@BVE NCs were characterized using various analytical techniques including XRD, UV-DRS, FESEM, FT-IR, EDAX, and TEM. UV-DRS results highlighted a bandgap energy reduction from 3.11 eV to 2.93 eV due to CuO integration with ZnO. TEM images confirmed the nanocomposite size to be between 35–50 nm. To evaluate the photocatalytic effectiveness of the biosynthesized nanocomposites, rhodamine b (RhB) was used as a representative contaminant. We thoroughly investigated the influence of multiple variables such as dye concentration, nanocatalyst amount, light source, and pH on the photocatalytic degradation of RhB. Under optimized conditions (0.15 g/L nanocatalyst, pH 11, UV light, and 3 ppm pollutant concentration), a remarkable 97.3% RhB degradation efficiency was achieved. Additionally, the antibacterial properties of the ZnO/CuO@BVE NCs were tested against six ATCC strains. Notably, they exhibited strong antibacterial action, especially against K. pneumoniae and P. aeruginosa, with a minimum inhibitory concentration (MIC) as low as 62.5 μg/mL. Furthermore, the nanocomposites demonstrated significant antifungal activity against C. albicans with an MIC of 31.2μg/mL. This research emphasizes the potential applications of ZnO/CuO@BVE NCs in environmental remediation and medical fields.

Synthesis and photocatalytic performance of composite g-C3N4 with functionalized multi-walled carbon nanotubes

A novel g-C3N4 composite photocatalyst was synthesized by one-step calcination using melamine and different functionalized multi-walled carbon nanotubes (MWCNT) as raw materials. The effect of additives on the photocatalytic performance of the composite g-C3N4 has been investigated. The results showed that the incorporation of functionalized MWCNT led to a porous structure in g-C3N4, increasing the specific surface area and availability of active sites. The addition of hydroxylated/carboxylated MWCNT (HMWCNT/CMWCNT) affected the band structure of g-C3N4 and reduced the band gap. The visible-light photocatalytic degradation efficiency of Rhodamine B (RhB) using g-C3N4 composited with various types and amounts of MWCNT was evaluated. Among them, g-C3N4 with 1 wt% CMWCNT showed the highest photocatalytic degradation efficiency of RhB and still had 92.71% photocatalytic activity after 5 cycles of degradation.

Direct fabrication of metal-free graphene nanohairs/polyimide heterojunction for the highly efficient photocatalytic degradation of industrial dyes

A single-step three-dimensional graphene nanohairs/polyimide heterojunction (GPH) is fabricated using a CO2 laser-assisted method. An optimization process has been systematically carried out to obtain high-quality graphene nanohairs on polyimide. The obtained GPH was characterized by X-Ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy. Using the fabricated GPH as a photocatalyst, the photocatalytic degradation of three industrial dyes namely, methyl orange (MO), methylene blue (MB), and Rhodamine B (RhB), was studied under UV irradiation. The decolorization of the samples was studied by UV–vis absorbance spectrometer. Starting from 5 ppm dye solutions with GPH, the degradation efficiencies of 97 % for MO in 60 min, 98 % for RhB in 90 min, and 88 % for MB in 170 min, were achieved. Furthermore, the stability of GPH was evaluated and after five runs, the degradation efficiency of MO, RhB and MB is decreased to 85 %, 91 % and 75 % from 98 %, 97 %, and 88 %, respectively. The mechanism for the degradation of dyes using GPH was proposed. The simple and feasible fabrication of GPH with excellent photocatalytic dye degradation efficiency would create the new insight into the flexible heterostructures for degrading the industrial wastewater treatment process.

Synergistic effect of stirring and marigold shaped Cu2FeSnS4 nanostructure for the enhanced performance of Rhodamine B degradation under visible light

The success of Photocatalysis for environmental applications strongly relies upon the availability of suitable energy spectrum as well as absorption of photon energy by the photocatalyst to generate reactive oxygen species (ROS) which are deemed necessary for dye removal. Present work report the solvothermally synthesized Cu2FeSnS4 (CFTS) marigold flower shaped nanostructures which demonstrates significant degradation efficiency against rhodamine B (RhB) dye. The formation of single-phase tetragonal stannite structure of CFTS nanoparticles with lattice constant values a = b = 5.48 Å and c = 10.61 Å was confirmed by XRD analysis. FESEM studies reveals the formation of self-assembled thin sheets of nanoflakes with uniform average thickness 25-30 nm and fringe spacing between adjacent lattice for 〈204〉 atomic plane is found to be 0.19 nm calculated by HR-TEM. The excellent RhB degradation efficiency of 92.1% under visible light within 05 minutes was achieved under synergetic effect of stirring and synthesized CFTS material.