Mixed Dye Research Articles

A New Strategy of Chemical Photo Grafting Metal Organic Framework to Construct NH2-UiO-66/BiOBr/PVDF Photocatalytic Membrane for Synergistic Separation and Self-Cleaning Dyes.

Photocatalytic membranes are typical multifunctional membranes that have emerged in recent years. The lack of active functional groups on the surface of membranes made of inert materials such as polyvinylidene fluoride(PVDF) makes it difficult to have a stable binding interaction with photocatalysts directly. Therefore, in this study, we developed a simple method to prepare NH2-UiO-66/BiOBr/PVDF(MUB) membranes for efficient dye treatment by grafting benzophenolic acid-functionalized NH2-UiO-66 onto the surface of membranes with photocatalytic properties under visible light irradiation using benzophenolic acid with photoinitiating ability as an anchor. The structural characteristics, photocatalytic properties, antifouling properties, and reusability of the composite membranes were investigated in subsequent experiments using a series of experiments and characterizations. The results showed that the benzophenone acid grafting method was stable and the nanoparticles were not easily dislodged. The MUB composite membrane achieved a higher dye degradation efficiency (99.2%) than the pristine PVDF membrane at 62.9% within a reaction time of 180 min. In addition, the composite membranes exhibited higher permeate fluxes for both pure and mixed dyes and also demonstrated outstanding water flux recovery (>96%) after the light self-cleaning cycle operation. This combination proved to improve the performance of the membranes instead of reducing them, increasing their durability and reusability, and helping to broaden the application areas of membrane filtration technology.

MoS2 Nanosheets@Metal organic framework nanocomposite for enhanced visible light degradation and reduction of hazardous organic contaminants

Present research focuses on the environmental cleanup of hazardous organic pollutants that are discharged into the natural aquatic bodies which upshots an undesirable shift in the ecological balance. Recently, aromatic nitro compounds and hazardous organic dyes have been recognized as a threat to fauna, flora and human life forms. Therefore, effective and selective eradication of these hazardous pollutants from wastewater systems is a pressing global issue for the academic community. This study aims to design a MoS2 Nanosheets (NS)@Cu-MOF (MS−HK) catalyst via a convenient hydrothermal approach for the elimination of organic and aromatic nitro contaminants from wastewater effluent. Under visible light irradiation, this photocatalyst presented 96.4% removal efficiency for Rose Bengal (RB) dye within a short duration of 30 min, with a first order degradation rate constant of 0.12223 min−1and a catalyst loading of 240 mg/L. Again, the rate constant of the room temperature reduction of 2,4,6−trinitrophenol (TNP) using NaBH4 as a reducing agent, in presence of the prepared nanocatalyst was calculated to be 2.7 × 10−3 s−1. This excellent degradation efficiency could be due to the loading of HKUST-1 with a narrow band gap semiconductor MoS2 leading to enhanced visible light absorption, effective separation and transport of photoinduced h+−e− pairs that limit their recombination. The plausible photodegradation mechanism was supported by photoluminescence and radical trapping experiments. In addition, the impact of various inorganic ions, water matrices, environmental conditions, different dye molecules and mixed dye system was explored on the RB degradation of the synthesized catalyst. Meanwhile, the as-prepared MS−HK nanocomposite displayed significant stability during the photocatalytic experiments, as evident from XRD results, until four successive cycles maintaining an outstanding degradation efficiency of >89%.

Preparation of copolymer brush‐type restricted access microspheres with adjustable adsorption selectivity to variety of dyes

AbstractRestricted access materials (RAMs) with adjustable selectivity was developed for the removal and detection of residual dyes for the solve problems of dye contamination. In this work, using homemade poly(4‐vinylbenzyl chloride‐co‐divinylbenzene) (PVBC/DVB) microspheres as substrate and successive two‐step surface‐initiated atom transfer radical polymerization (SI‐ATRP) as synthesis method, the two types of monomers, sodium 4‐vinylbenzene sulfonate (Nass) and styrene (St) were first grafted for constructing mixed interactions of adsorption sites, and then the hydrophilic glycidyl methacrylate (GMA) was polymerized, following by hydrolysis to construct diol groups on the external PVBC/DVB as the restricted access sites. The developed PVBC/DVB@poly(St‐co‐Nass)@poly(GMA) of adsorption properties was investigated by six dyes including methylene blue (MB), basic fuchsin (BF), acid fuchsin (AF), neutral red (NR), methyl orange (MO), and Congo red (CR), the adsorption capacities of those dyes and the removal rate for the binary mixed dye solution both rely on the ratio of St/Nass, confirming the adjustable adsorption selectivity. When PVBC/DVB@poly(St‐co‐Nass)@poly(GMA) was packed as solid phase extraction adsorbent in couple with UV–vis spectrum, it was applied to the determination of MB and BF in the water, fish and shrimp, good linearity with satisfactory recoveries for MB and BF are obtained to show the favorable practicability.

Regenerated cellulose/polyethyleneimine composite aerogel for efficient and selective adsorption of anionic dyes

With the requirement of sustainable development in modern society, it is urgent to develop the environmentally friendly adsorbents for selective filtration and separation of toxic dyes from hazardous wastewater. Herein, a stable, reusable, and highly compressible three-dimensional regenerated cellulose/polyethyleneimine composite aerogel (RC/PCA) was successfully prepared directly using cheap cotton pulp as raw material and N-methyl morpholine-N-oxide (NMMO) as the “green” solvent, in which the regenerated cellulose (RC) with hydroxyl groups converted from cotton can interact with polyethyleneimine (PEI) with amine groups. After further crosslinking of RC, PEI and glutaraldehyde (GA), the RC/PCA can be used to selectively absorb anionic dyes from the ternary mixed dye system, which maximal adsorption capacity for methyl orange (MO) can be up to 980.39 mg/g. Moreover, the obtained stable RC/PCA can be repeatedly used at least 50 times for the removal of MO (20 mg/L) with a high filtration efficiency of 99.8 %. The kinetics and isothermal adsorption data were described via the pseudo-second-order kinetic model and Langmuir model. Therefore, this research proposes a novel strategy for developing low-cost, highly efficient, regenerated cellulose-based adsorbents to extract organic dyes from wastewater for potential practical applications.

Potential investigation of combined natural dye pigments extracted from ivy gourd leaves, black glutinous rice and turmeric for dye-sensitised solar cell

Environmental sustainability, resource availability, and cost-effectiveness are the driving forces behind the search for natural sensitised dyes to replace synthetic ones. Using a combination of pigments as the sensitised dye in dye-sensitised solar cells (DSSCs) offers several advantages over using a single pigment. In this present study, natural dyes with different pigments were extracted from three local plants: Coccinia grandis (Ivy gourd leaves, IGL), Oryza sativa Linn (Black glutinous rice, BGR), and Curcuma longa L. (Turmeric, TM). Each colour extract absorbed various wavelengths of light. It was found that the single IGL-dye (green) had a greater light absorption and energy band gap over visible light than other extracts (dyes). Then combinations of these dyes were examined. A sensitised dye combination with a primary to secondary dye in a volumetric ratio of 80/20 exhibited multiple energy band gaps, implying multiple electron excitations at different photon energy levels. Compared to other mixed dyes, IGL/TM-dye had the highest absorbance and electron excitation at three wavelengths with the smallest energy band gap values of 1.74, 2.51, and 2.59 eV. The IGL-dye had the highest DSSC efficiency of 0.15 % for single dyes, followed by the TM-dye and BGR-dye, which had 0.12 % and 0.04 %, respectively. Interestingly, for combined dyes, the IGL/TM dye increased DSSC efficiency to 0.3 %. Since natural dyes tend to be less effective in DSSCs than synthetic dyes because they have a narrower absorption range, higher redox potentials, shorter operational lifetimes, higher rates of electron recombination, and different molecular structures, the dye co-sensitization strategy is one of the best ways to make more effective cells in the future.

Synthesis and Characterization of a Nano‐Composite CuO@Zn−2‐PTZ {Zn−2‐PTZ=bis[5‐(2‐pyridyltetrazolato)]diaquazinc(II)} for Efficient Photo‐catalytic Degradation of Methylene Blue (MB), Methyl Orange (MO) and mixed(MB‐MO)Dyes in Sunlight

AbstractRemoval of organic contaminants such as azo dyes is highly desirable from the industrial waste waters because of their toxicity, stability, and mutagenic properties. Herein, the nano‐composite CuO@Zn−2‐PTZ has been synthesized by a simple hydrothermal method and characterized by a combination of techniques like Powder X‐Ray Diffraction (PXRD), UV‐Visible spectroscopy, Fourier Transform Infrared (FT‐IR) spectroscopy, Scanning Electron Microscopy‐Energy Dispersive X‐ray analysis (SEM‐EDX) etc. The band gap of the composite was found to be 2.07 eV, indicating the spread of absorption in to the visible region in comparison to the high (3.76 eV) band gap of the parent metal organic framework (MOF) Zn−2‐PTZ. The composite CuO@Zn−2‐PTZ exhibited much higher photo degradations, under natural sunlight, towards the decompositions of the cationic [Methylene Blue (MB)] and anionic [Methyl Orange (MO)] dyes as well as mixed MB and MO dyes taken in water. A comparative study was also undertaken by taking CuO nanoparticles and the parent MOF separately with the same set of dyes under same conditions to substantiate the above. The enhancement of photo‐catalytic activity has been caused by the formation of a p‐n hetero‐junction in the composite. The Langmuir‐Hinshelwood model showed that the degradation rates of the dyes follow pseudo‐first‐order kinetics.

Unleashing the visible light-exposed photocatalytic potential of V2O5/g-C3N4 nanocomposites for dye industries wastewater cleaner production

Dealing harmful dye-containing effluent from the textile sector significantly contributes to water contamination. The persistence of these dyes in wastewater complicates traditional treatment approaches, emphasizing the necessity for efficient photocatalytic materials for dye pollution degradation. Due to its unique features, V2O5/g-C3N4 nanocomposites are discovered as promising photocatalysts in this area. The V205 nanoparticles act as electron acceptors, while g-C3N4 acts as electron donors, thus encouraging charge separation and increasing photocatalytic activity. The V2O5/g-C3N4 nanocomposites are characterized using XRD, FTIR spectroscopy, SEM, TEM, XPS, and UV-DRS. Cationic dyes, anionic dyes and mix dyes (1:1 mixture of cationic and anionic dyes) are used to test the photocatalytic activity of the nanocomposites. Photocatalytic activity shows that V2O5/g-C3N4 nanocomposites are more active than their precursors. The V5G-2 nanocomposite degrades anionic (Rose Bengal (85.1%) and Xylenol Orange (77.6%), cationic (Auramine O (75% and Crystal Violet (79.5%), and mixed dyes (81%), after 120 min of irradiation. This study introduces a novel technique for synthesizing V2O5/g-C3N4 nanocomposites using solvothermal and ultrasonic processes. The findings of this research provide significant knowledge for the development of photocatalysts with enhanced efficiency in the degradation of dye pollutants.

Fabrication of physically multi-crosslinked sodium alginate/carboxylated-chitosan/montmorillonite-base aerogel modified by polyethyleneimine for the efficient adsorption of organic dye and Cu(II) contaminants

Efficient removal of contaminants, like heavy metal ions and dyes, from wastewater by eco-friendly and low-cost adsorbent is highly desirable. Herein, a green aerogel was prepared using sodium alginate/carboxylated chitosan/montmorillonite (MSC-P) as the basic framework, followed by polyethyleneimine functionalized and Ca2+ post-crosslinking. The multi-crosslinked aerogel exhibited the excellent adsorption capacity towards methylene blue (MB), Congo red (CR) and Cu(II), with the qm being 723.97 mg/g, 1573.21 mg/g and 203.99 mg/g, respectively. The mathematical model suggested that the adsorption process for MB fitted pseudo-first-order kinetics model better, whereas the CR and Cu (II)’s adsorption process were conformed to pseudo-second-order kinetics model. Moreover, the adsorption isotherm for three contaminants could be well described by Langmuir model, suggesting that the adsorption process was spontaneous and mainly controlled by monolayer coverage. Moreover, MSC-P aerogel exhibited good reusability as the removal efficiencies for MB and Cu(II) were 85.16 % and 51.4 % after ten cycles of adsorption–desorption, respectively. Importantly, it possessed considerable simultaneous removal ability for binary system mixed dyes. In combination of FTIR analyses, it was found that electrostatic attraction, hydrogen bonding, coordination and cation exchange were the main adsorption mechanisms involved. Therefore, the as-prepared aerogel can be considered as a promising adsorbent for the treatment of wastewater.

A modification and selective adsorption of cationic dyes based on UiO-67

A metal polyphenol compound Fe-TA (TA is tannin) was applied for surface modification to improve the selective adsorption capacity of UiO-67 on cationic dyes. The modified material UiO-67@Fe-TA, which named UFT-X, exhibited significantly selective adsorption of cationic dye. Then the Freundlich isotherm model and quasi second-order kinetics model were employed to characterize the adsorption of UiO-67@Fe-TA, and the maximum adsorption quantity was 1415.56 mg/g. Furthermore, the adsorption efficiency remained above 80% after 6 cycles. The research provided a strategy of materials design and modification for selective adsorption on mixed dyes.

Upgraded β-cyclodextrin-based broad-spectrum adsorbents with enhanced antibacterial property for high-efficient dyeing wastewater remediation

The dyeing wastewater contains amounts of refractory organic compounds, and severely endangers the ecosystem and human health. To alleviate this problem, in this study, the low-cost broad-spectrum nano-adsorbent (denoted as CD/CA-g-CS) with strong antibacterial activity has been synthesized by chemical binding of β-cyclodextrin (β-CD) with chitosan (CS) and citric acid (CA) for high-efficient dyes scavenger. Taking advantage of the extraordinary water insolubility, porous nature and abundant surface groups, the synthesized CD/CA-g-CS outperforms the previously reported adsorbents in terms of adsorption performance. The CD/CA-g-CS exhibits ultrahigh adsorption capacities of 801.66, 770.50 and 946.66 mg/g, respectively mg/g for the cationic dyes of malachite green (MG), basic red (BR) and methylene blue (MB), respectively, while 389.64, 619.60 and 429.22 mg/g for the anionic dyes of acid blue (AB), acid red (AR) and acid yellow (AY), respectively. The chemical monolayer absorption is further demonstrated by the analysis based on the pseudo-second-order adsorption kinetics and Langmuir isotherm models. The regenerable CD/CA-g-CS not only performs well in one-step removal of the mixed dyes in the simulated sewage, but also exhibits superior performance in purifying real industrial wastewater. Moreover, CD/CA-g-CS endowed with antibacterial activity leads to an inhibition rate of over 99.99 % for E. coli. The newly developed CD/CA-g-CS adsorbents are highly promising for high-efficient dyeing wastewater remediation.

Remediation of charged organic pollutants—binding motifs for highly efficient water cleaning with nanoparticles

AbstractMany charged organic molecules behave as persistent and hazardous pollutants with harmful effects on human health and ecosystems. They are widely distributed related to their charged molecular structure that provides water solubility. In order to track the fate and behavior of such pollutants, charged dyes with specific absorption in the visible spectra serve as convenient model compounds. We provide a platform of smart adsorbers that efficiently remediate positively and negatively charged dyes (crystal violet and Amaranth) from water. Metal oxide nanoparticles serve as a core with an intrinsically large surface area. The surface potential was tuned towards positive or negative by decorating the cores with self‐assembled monolayers of dedicated long‐chained phosphonic acid derivatives. Selective remediation of the dyes was obtained with corresponding oppositely charged core‐shell nanoparticles. Mixed dye solution can be cleaned by a cascade approach or by applying both particle systems simultaneously. The removal efficiency was determined as a function of particle concentration via UV‐spectroscopy. The results of remediation experiments at different pH values and using superparamagnetic iron oxide nanoparticle cores lead to a simple process with recycling capability.

Applicability and Freshness Control of pH-Sensitive Intelligent Label in Cool Chain Transportation of Vegetables.

Freshness is one of the main factors affecting consumers' purchase of food. The freshness indicator labels of packaged fresh green bell pepper (Capsicum annuum L.) and greengrocery (Brassica chinensis L.) were constructed, and pH-sensitive indicator labels based on the dye of anthocyanin and the mixing dye of methyl red and bromothymol blue were prepared in this study. At the same time, the color, chlorophyll content and vitamin C content of vegetables were measured in order to explore the applicability of indicator labels in the cool chain transportation of vegetables. Compared with the nature dye, the chemical dye-type indicator labels are more sensitive to pH changes. The results showed that the mixed indicator intelligent label had the best indication effect, and the MB 2 (mixing 1 g/L methyl red and bromothymol blue solutions at a ratio of 3:2 with a concentration of 70 mL/L in indicator film solution) indicator label could effectively indicate the freshness changes in vegetables during storage. Meanwhile, the color changes of the MB 2-type indicator label were correlated with the colors change of the sample, changes in nutrients, and changes in CO2 content inside the packaging. In addition, freshness detection models for green bell pepper and greengrocery by using color information of MB 2 intelligent labels were established. Hence, this pH-sensitive label can be applied as a promising intelligent packaging for non-destructively monitoring the freshness of respiratory and non-respiratory climacteric vegetables.

A parametric study on intensified degradation of textile dye water using hydrodynamic cavitation based hybrid technique

In this paper, a detailed investigation of the treatment of model textile dye wastewater (MTDW) by applying a hybrid approach of hydrodynamic cavitation (HC) coupled with UV light and different oxidants is reported. A distinct hybrid strategy of HC combined with inline UV and different oxidants was employed to treat model textile dye wastewater comprising mixed dyes under neutral to alkaline conditions and in the presence of salt and detergent, which form significant components of textile wastewater. The model textile dye wastewater was made of three dyes: Reactive Yellow 84, Reactive Black 8, and Reactive Violet 5 with 100 ppm of total concentration. Effects of various operating conditions, such as feed pressure at the venturi inlet, initial pH, process time, and different oxidizing agents, on percentage COD reduction were investigated. The extent of dye decolourization using HC combined with different oxidizing agents, viz., hydrogen peroxide (H2O2), sodium persulfate (NaPS), and potassium peroxymonosulfate (PPMS), were studied. HC coupled with UV and potassium peroxymonosulfate (PPMS) oxidant produced maximum decolourization of dyes to the extent of 100 % at pH 7. A maximum COD reduction of 87.7 % was obtained at the optimized operation conditions of hydrodynamic cavitation (HC) coupled with UV and PPMS. The treatment of model dye wastewater utilizing a hybrid strategy of HC+UV+PPMS achieved a synergetic index of 1.92, which was significantly better than standalone treatments. The current work contributes significantly to our understanding of the performance of cavitation-based systems for treating complicated textile effluent.

Magnetic nanocellulose-based adsorbent for highly selective removal of malachite green from mixed dye solution

Herein, a novel magnetic adsorbent (BC/AA/MN@Fe3O4) was successfully prepared from waste bamboo fiber tissue and montmorillonite, and subsequently applied for the highly selective removal of malachite green (MG, removal efficiency = 97.3 %) from the mixed dye solution of MG with methyl orange (MO, removal efficiency = 4.5 %). The magnetic adsorbent has a high porosity with abundant mesopores. In the single dye MG solution, the adsorbent could effectively remove MG over a wide pH range from 4 to 10, and the maximum adsorption capacity (qmax) was 2282.3 mg/g. Moreover, the magnetic adsorbent could remove MG from various solutions including mixed dye solution, high salinity solution, and real river water dye solution. The thermodynamic results proved that the adsorption process of MG was spontaneous and endothermic. The adsorption of MG was due to the comprehensive effects of electrostatic attraction, hydrogen bonding interactions and ions exchange, between the adsorbent and MG. Furthermore, the BC/AA/MN@Fe3O4 exhibited an excellent reusability with adsorption efficiency above 53.4 % after five consecutive cycles. Therefore, the prepared magnetic nanocellulose-based adsorbent was expected to be a promising material for highly selective adsorption and separation of MG from mixed dye solution.

Technical aesthetic in the works of Alberto Buri

The artistic technique has an important role in the constructive analyzes of the plastic visual achievements according to the relationship of the artistic elements and the mechanisms of their operation with each other, so the artist deliberately shows the aesthetics of these techniques through his own artistic and technical style according to his conscious ability to move away from the classical traditions. The research consists of four chapters, the chapter included The first is on the methodological framework of the research, so the problem was summed up by the following question: What are the technical aesthetics in the works of Alberto Buri? As for its importance, it was represented by studying the works of the artist (Alberto Buri) for his stylistic and technical uniqueness among the artists of his era. As for the spatial borders (Europe and the United States of America), the temporal borders of the period (1949-1960). Among the results reached by the researcher: The (Buri) style was associated with the technique of existing objects, as it took the collection of dilapidated materials in order to liberate the artwork from all classical constraints and adopt contemporary techniques He mixed dyes with other materials to form different surfaces that were strange.

Direct sunlight induced room temperature synthesis of anticancer and catalytic silver nanoparticles by shrimp shell waste derived chitosan

The use of marine waste derived chitosan (CS) for the synthesis of nanomaterials is considered as one of the effective routes for bio-waste management and recovering functional products. Herein, CS capped silver nanoparticles (Ag NPs-CS) with potential anticancer and dye pollutants adoption properties have been synthesized photochemically under direct sunlight. To obtain, CS, shrimp shell waste was subjected to a serious of standard demineralization, deproteinization and deacetylation processes. The electronic absorption peak (400 nm) denoting surface plasmonic resonance of Ag NPs and infrared peaks relevant to CS (3364 cm−1 of OH/NH2, 2932 cm−1 of CH, and 1647 cm−1 of -CO) exhibited peaks confirmed the formation of CS-Ag NPs. Ag NPs-CS exhibited anticancer activity against Human lung adenocarcinoma cell lines (A549), the maximum cell death noticed at the concentration of 20 μg/mL and 70 μg/mL was 20 and 52 %, respectively. An aqueous Ag NPs-CS (100 μg/mL) was degraded ≥95 % of mixed dye target solution (25 mg/mL) containing equal volume of cationic dye (Methylene blue and Rhodamine B) and anionic dye (methyl orange). Therefore, these findings suggest that the shrimp shell waste derived CS can be used for the synthesis of CS-Ag NPs with potential biomedical and environmental applications.

Accordion-like multilayer Ti3C2Tx MXene sheets decorated 1D Mn2O3 nanorods-based nanocomposites: An efficient catalyst for swift removal of single and mixed dyes

Ti3C2Tx-MXene-based nanocomposites were prepared with 1D Mn2O3 through the electrostatic self-assembly method. The synthesized nanocomposites are investigated for photocatalytic degradation of individual dye, mixed cationic and anionic dyes under visible light irradiation. The cubic bixbyite structure of 1D Mn2O3 was confirmed in the nanocomposites by the XRD and Raman spectroscopy analyses. The band gap energy of the 1D Mn2O3-Ti3C2Tx MXene (5–20 wt%) nanocomposites was estimated to range from 0.9 eV to 0.2 eV through the Tauc plot, implying their application as a photocatalyst under visible light illumination. The randomly oriented nanorods were decorated on the accordion-like Ti3C2Tx MXene sheets and were confirmed by the SEM, FESEM and TEM analyses. The average diameter of Mn2O3 nanorods (87 nm) and interlayer spacing of Ti3C2Tx MXene sheets (172 nm) were measured from FESEM analysis. The Mn, O, Ti, C and F elemental compositions of the composites were analyzed by the EDAX. The 100% degradation efficiency of methylene blue (MB) dye was achieved in the presence of 1D Mn2O3-Ti3C2Tx (20 wt%) nanocomposite and the same was used to degrade the mixed cationic and anionic dyes. In mixed dyes, methyl orange (MO), rhodamine B (RhB) and methylene blue (MB) achieved degradation efficiencies of 82%, 80% and 96%, respectively. Based on the scavenger's experiment, the hydroxyl radical (OH−) and superoxide anion radicals (O2°−), were the dominant reactive species in the dye degradation.

Application of a Mixed-Ligand Metal–Organic Framework in Photocatalytic CO2 Reduction, Antibacterial Activity and Dye Adsorption

In this paper, a known mixed-ligand MOF {[Co2(TZMB)2(1,4-bib)0.5(H2O)2]·(H2O)2}n (compound 1) was reproduced, and its potential application potential was explored. It was found that compound 1 had high photocatalytic activity for CO2 reduction. After 12 h of illumination, the formation rate of CO, which is the product of CO2 reduction by compound 1, reached 3012.5 μmol/g/h. At the same time, compound 1 has a good antibacterial effect on Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Candida albicans (C. albicans), which has potential research value in the medical field. In addition, compound 1 can effectively remove Congo Red from aqueous solutions and achieve the separation of Congo red from mixed dye solutions.

Construction of hexagonal spindle-shaped Fe-MOFs induced by cationic copolymer and its application for effective wastewater treatment.

The environment and human health are in danger due to the long-term enrichment and buildup of organic pesticides, dyes, and harmful microbes in wastewater. The development of functional materials that are efficient for treating wastewater remains a significant problem. Eco-friendly hexagonal spindle-shaped Fe-MOFs (Hs-FeMOFs) were created in this study under the influence of cationic copolymer (PMSt). The mechanism of crystal growth and development of its unique morphology were described after looking into impact factors for the ideal circumstances and being characterized by XRD, TEM, XPS, and other techniques. It revealed that Hs-FeMOFs possess an enormous supply of adsorption active sites, a strong electropositivity, and the nanometer tip. Then, typical organic pollutants, such as herbicides and mixed dyes, as well as biological pollutants bacteria, were chosen to assess its efficacy in wastewater treatment. It was discovered that the pendimethalin could be quickly removed in wastewater and the removal rate reached 100% within 10min. In separation of mixed dyes, the retention rate of malachite green (MG) reached 92.3% in 5min and with a minimum inhibitory concentration of 0.8mg/mL and demonstrated strong activity due to the presence of cationic copolymers. In actual water matrix, Hs-FeMOF could also play excellent adsorption and antibacterial activity. In summary, a novel, environmentally friendly MOF material with good activity was successfully created by cationic copolymer induction. It offers a fresh approach to develop functional materials in wastewater treatment.

Synergistic Effect of BiVO4/P-g-C3N4 Heterojunction with Enhanced Optoelectronic Properties on Synthetic Colorants under Visible Light

Environmental remediation in the presence of robust semiconductor photocatalysts by utilizing renewable energy sources is of keen interest among researchers. In this study, we synthesize a BiVO4/P-g-C3N4 semiconductor heterojunction photocatalytic system through a hydrothermal route followed by utilizing a total-solvent evaporation method. The optical and electronic properties of the as-prepared heterojunction are characterized via various spectroscopic techniques. Rhodamine B (RhB) and Congo Red (CR) are used as synthetic colorants to evaluate the photocatalytic performances of BiVO4/P-g-C3N4. In addition, the chemical environment of the photocatalyst and its mechanistic pathways are confirmed through X-ray photoelectron spectroscopy and electrochemical Mott–Schottky analysis. The BiVO4/P-g-C3N4 photocatalyst shows higher photodegradation (96.94%) of the mixed synthetic dyes under simulated solar-light irradiation. The as-synthesized BiVO4/P-g-C3N4 heterojunction significantly promotes the quick separation of photoexcited carriers due to the excellent synergetic properties, the extended light absorption, and the photoelectrochemical response. Furthermore, a possible type-II charge transfer mechanism is adopted for the BiVO4/P-g-C3N4 system after investigating the band potentials, active species, and charge carrier migration over the heterojunction interface.