Photocatalytic Degradation Of Organic Dyes Research Articles

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 radical-quenching experiments proved that ·O2– and h+ played crucial roles in the photocatalytic reaction. The suitable band potential of Bi2WO6 (3.19 eV) and TiO2 (2.89 eV) 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.

Morphological studies, photocatalytic degradation of organic dyes and anticancer potential of copper sulfide nanoparticles prepared from bis(diallyl dithiocarbamato)copper(II) complex

Bis(diallyl dithiocarbamato)copper(II) complex was synthesized and characterized by single crystal X-ray crystallography. The molecular structure revealed dimeric copper(II) complex consisting of two copper(II) ions that coordinate two molecules of diallydithiocarbamato anions in bidentate chelating modes and the centrosymmetrically related diallydithiocarbamato anions bridges the S-atom of the adjacent chelating ligand to formed square pyramidal geometry around the copper(II) ions. Copper sulfide nanoparticles were prepared at 160°C by thermolysis of the copper(II) complex in dodecylamine (DDA), hexadecylamine (HDA), and octadecylamine (ODA) to study the effect of capping agents on the structural morphologies, photocatalytic properties, and anticancer potential of the as-prepared copper sulfides nanoparticles. Powder X-ray diffraction patterns confirmed Cu9S5 digenite crystalline phases for CuS-DDA and CuS-HDA while CuS-ODA is covellite crystalline phase. HRTEM images showed spherical particles with particle sizes in the range 2-25 nm. The copper sulfide nanophotocatalysts are efficient for the degradation of bromophenol blue with the highest photocatalytic efficiency of 95.14% for CuS-DDA followed by CuS-HDA with 94.52% and 93.95% for CuS-ODA. The anticancer potentials of the compounds showed that CuS-HDA is the most potent with IC50 values of 1.22 µg/mL against HEK293 and 28.78 µg/mL against HeLa.

Graphene-based Semiconductors for Photocatalytic Degradation of Organic Dye from Wastewater: A Comprehensive Review

Graphene-based Semiconductors for Photocatalytic Degradation of Organic Dye from Wastewater: A Comprehensive Review

Synthesis of Group IIB and IVB Metal Complexes of 3‐Nitroaniline for Photocatalytic Degradation of Organic Dyes

AbstractIn the current research, new metal complexes have been synthesized by using the greener synthetic approach in which 3‐Nitroaniline reacts with the elements of group‐IIB and group‐IVB. According to this method, ligand and metals were dissolved in 1,4‐dioxane and stirred at room temperature for a specific time period. The method for the preparation of metal‐base complexes is quite simple and cost‐effective. To identify the synthesized compounds various physio‐chemical analytical techniques were used such as Melting point, FT‐Raman Spectroscopy, FT‐IR Spectroscopy, Thermogravimetric analysis, and Scanning electron microscope (SEM) that provide significant data about the general structural characteristics of synthesized compounds. The percentage degradation efficiency of synthetic dyes was obtained as 57 %, 66 %, and 97 % using the synthesized compounds as photocatalysts. A statistical tool, RSM was used for the optimization of parameters (Concentration of Dye, Dose of Catalyst, and contact time).

Green Synthesis of Platinum Nanoparticles Using Polymer Bio-reduction Approach and Their Photocatalytic Organic Dye Degradation

Green Synthesis of Platinum Nanoparticles Using Polymer Bio-reduction Approach and Their Photocatalytic Organic Dye Degradation

Peroxymonosulfate enhanced photocatalytic degradation of organic dye by metal-free TpTt-COF under visible light irradiation

Recently, the activation of persulfate (PDS) by non-metallic photocatalysts under visible light has attracted significant interest in applications in environmental remediation. This study presents a pioneering investigation into the combined application of the TpTt-COF and PMS for visible light degradation of organic dyes. Synthesized orange TpTt-COF monomers exhibit exceptional crystallinity, a 2D structure, and notable stability in harsh conditions. The broad visible light absorption around a wavelength of 708 nm. The TpTt-COF emerges as a promising candidate for photocatalytic dye degradation. The study addresses high charge recombination in the TpTt-COF, highlighting the crucial role of its electron donor and acceptor for the PMS activation. Comparative analyses against traditional photocatalytic materials, such as the metal-free carbon-based material g-C3N4 and transition metal-containing TiO2, demonstrate TpTt-COF's superior performance, generating diverse free radicals. In simulated experiments, the TpTt-COF's degradation rate surpasses PMS-combined g-C3N4 by 13.9 times. and 1.6 times higher than the TpTt-COF alone. Remarkably, the TpTt-COF maintains high activity under harsh environments. Investigations into the degradation mechanism and the TpTt-COF's reusability reveal its efficiency and stability. Under visible light, TpTt-COF facilitates efficient electron–hole separation. Combining the TpTt-COF with PMS produces various radicals, ensuring effective separation and a synergistic effect. Radical quenching experiments confirm the pivotal role of O2-· radicals, while ·OH and SO4-· radicals intensify the degradation. After five cycles, TpTt-COF maintains an impressive 83.2% degradation efficiency. This study introduces an efficient photocatalytic system mediated by PMS and valuable insights into governing mechanisms for organic pollutant degradation in water environments.

Photocatalytic degradation of organic dyes in water using semiconductor ZnO nanoparticles synthesized using Crataegus mexicana extract

In this work, the synthesis of zinc oxide (ZnO) nanoparticles was made using an eco-friendly methodology with a natural extract. The fruit of tejocote (Crataegus mexicana) was used as a stabilizing agent for synthesizing zinc oxide nanoparticles (NPs). Once the NPs were obtained, diverse characterization techniques were used to determine the physicochemical and optical properties of the ZnO NPs; the ultraviolet–visible spectroscopy was used to determine the uv absorption spectra of ZnO NPs and the bandgap of the material, the FT-IR spectrum of the ZnO NPs shows the presence of the Zn–O bond at 560 cm−1, XRD results show that the ZnO NPs exhibit a hexagonal crystal structure zincite type, the SEM confirms slight agglomerations between nanoparticles, Also from TEM results, the nanoparticles present a quasi-spherical morphology with sizes ranging from 18.25 nm to 36.88 nm, indicating an influence of the concentration of the Crataegus mexicana extract in the synthesis process of ZnO NPs. Photoluminescence spectroscopy of ZnO NPs shows strong emission bands in the visible spectrum around 425 nm, 467 nm, and 492 nm, and weak emission bands in the UV spectrum were observed. Finally, a photocatalytic study was realized for the photodegradation of 5 pollutant dyes: methylene blue (MB), malachite green (MG), congo red (CR), rhodamine b (RB), and methyl orange (MO). The results show degradation of the organic dyes after 180 min by a photodegradation process where ZnO nanoparticles act as a photocatalyst, indicating that the synthesized ZnO nanoparticles have excellent photocatalytic properties.

Highly efficient tin oxide and polyaniline-tin-oxide nanostructured materials for photocatalytic degradation of organic dyes

Herein, polyaniline-tin oxide (PANI-SnO2) nanostructured materials (NSMs) were prepared by incorporating SnO2 nanoparticles into the polyaniline (PANI) chain produced from aniline monomers. The structural, morphological, and optical features of materials were described using the scanning electron microscope (SEM), Fourier-transform infrared (FT-IR), powder X-ray diffraction (pXRD), and ultraviolet-visible (UV–Vis) spectroscopy. While a thermogravimetric analysis (TGA) was performed to assess the thermal stability of NSMs. Additionally, the as-prepared PANI-SnO2 NSMs were employed as photocatalysts to degrade several dyes, including rhodamine B (RhB), methyl orange (MO), methylene blue (MB), and methylene red (MR). The PANI-SnO2 photocatalyst showed degradation efficiencies of 84 %, 90 %, 92 %, and 60 % for RhB, MR, MO, and MB, respectively. Various factors, such as the amount of catalyst used, the amount of dye present, the effect of pH, and temperature, were also examined to determine the ideal conditions for degradation. The results showed that the photodegradation efficiency (PDE) of dyes was affected by these factors. Finally, the kinetics studies revealed that the PANI-SnO2 NSMs follow the pseudo-first-order kinetics, which makes them ideal for large-scale degradation of biological and chemical contaminants.

Sunlight driven photocatalytic degradation of organic pollutants by solvothermally synthesized rGO-BiVO4 nanohybrids

This study reports photocatalytic degradation of organic dyes by rGO-BiVO4 nanohybrids. rGO- BiVO4 nanohybrids were solvothermally prepared with different rGO loading (1.5, 3 and 6 %) and their structural, optical and photocatalytic properties were investigated. Effect of rGO loading on photocatalytic dye degradation was studied and the factors responsible were analyzed. Structural analysis was done using XRD and Raman analyses which clearly showed monoclinic phase of the BiVO4. FESEM images showed sub-micron spheres of BiVO4 along with sheet-like structures corresponding to rGO. A slight change in the band gap was observed from 2.2 eV for BiVO4 to around 2 eV for the rGO-BiVO4 nanohybrids. Band to band transitions as well as the transitions from the defect bands were observed from the PL spectra. Photocatalytic degradation studies of organic pollutant MB under natural sunlight showed 3 % rGO-BiVO4 to be the best photocatalyst which degraded 88.4 % of MB in 80 min with rate constant of 0.0244 min−1. It was observed that for obtaining a maximum catalytic efficiency an optimum loading of rGO proved to be best. In either case of higher or lower loading of rGO showed a lower degradation performance. Amongst the samples synthesized 3 % rGO loading was found to be the optimum rGO loading to have the lowest band gap (2 eV) as well as the reduced recombination that has resulted in highest photocatalytic efficiency under solar irradiation.

Multi-functional Copper Oxide Nanoparticles Synthesized using Lagerstroemia indica Leaf Extracts and their Applications

Developing multifunctional nanomaterials through environmentally friendly and efficient approaches is a pivotal focus in nanotechnology. This study aimed to employ a biogenic method to synthesize multifunctional copper oxide nanoparticles (LI-CuO NPs) with diverse capabilities, including antibacterial, antioxidant, and seed priming properties, as well as photocatalytic organic dye degradation and wastewater treatment potentials using Lagerstroemia indica leaf extract. The synthesized LI-CuO NPs were extensively characterized using UV–vis spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform-infrared spectroscopy (FT-IR). The colloid displayed surface plasmon resonance peaks at 320 nm, characteristic of LI-CuO NPs. DLS analysis revealed an average particle size of 93.5 nm and a negative zeta potential of -20.3 mV. FTIR and XPS analyses demonstrated that LI-CuO NPs possessed abundant functional groups that acted as stabilizing agents. XRD analysis indicated pure crystalline and spherical LI-CuO NPs measuring 36 nm in size. Antibacterial tests exhibited significant differential activity of LI-CuO NPs against both gram-negative (Escherichia coli, Salmonella typhimurium) and gram-positive (Staphylococcus aureus and Listeria monocytogenes) bacteria. In antioxidant tests, the LI-CuO NPs demonstrated a remarkable radical scavenging activity of 97.6% at a concentration of 400 μg/mL. These nanoparticles were also found to enhance mustard seed germination at low concentrations. With a remarkable reusability, LI-CuO NPs exhibited excellent photocatalytic performance, with a degradation efficiency of 97.6% at 150 μg/mL as well as a 95.6% reduction in turbidity when applied to wastewater treatment. In conclusion, this study presents environmentally friendly method for the facile synthesis of LI-CuO NPs that could potentially offer promising applications in biomedicine, agriculture, and environmental remediation due to their multifunctional properties.

Charge-Selective Photocatalytic Degradation of Organic Dyes Driven by Naturally Occurring Halloysite Nanotubes

This study explores the use of Halloysite NanoTubes (HNTs) as photocatalysts capable of decomposing organic dyes under exposure to visible or ultraviolet light. Through a systematic series of photocatalytic experiments, we unveil that the photodegradation of Rhodamine B, used as a model cationic dye, is significantly accelerated in the presence of HNTs. We observe that the extent of RhB photocatalytic degradation in 100 min in the presence of the HNTs is ~four times higher compared to that of bare RhB. Moreover, under optimized conditions, the as-extracted photodegradation rate of RhB (~0.0022 min−1) is comparable to that of the previously reported work on the photodegradation of RhB in the presence of tubular nanostructures. A parallel effect is observed for anionic Coumarin photodegradation, albeit less efficiently. Our analysis attributes this discrepancy to the distinct charge states of the two dyes, influencing their attachment sites on HNTs. Cationic Rhodamine B molecules preferentially attach to the outer surface of HNTs, while anionic Coumarin molecules tend to attach to the inner surface. By leveraging the unique properties of HNTs, a family of naturally occurring nanotube structures, this research offers valuable insights for optimizing photocatalytic systems in the pursuit of effective and eco-friendly solutions for environmental remediation.

Carbon-doped Bi2MoO6 nanosheet self-assembled microspheres for photocatalytic degradation of organic dyes

Abstract In this paper, carbon-doped Bi2MoO6 (C-Bi2MoO6) nanosheet self-assembled microspheres were prepared by using the solvothermal-calcination route to improve the photocatalytic activity of Bi2MoO6. The characterization results of x-ray diffractometry, Fourier transform infrared spectrometry, Raman scattering, scanning electron microscopy, transmission electron microscopy, BET specific surface area test, and x-ray photoelectron spectrometry indicated that C replaced the O2− anion in the Bi2MoO6 lattice, thinning the nanosheets, decreasing the size of the microspheres, and increasing the specific surface area of the Bi2MoO6. Ultraviolet–visible diffuse reflectance spectroscopy, photoluminescence, electrochemical impedance spectroscopy, transient photocurrent, and linear sweep voltammetry (LSV) spectroscopy demonstrated that the carbon doping reduced the band gap energy, raised the conduction band, and enhanced the photogenerated electron–hole pairs separation efficiency of Bi2MoO6. Benefiting from these favorable changes, the C-Bi2MoO6 microspheres prepared at a molar ratio of C to Bi of 4 (4C-Bi2MoO6) exhibited the highest photocatalytic activity, and the photocatalytic degradation rate constant of rhodamine B by 4C-Bi2MoO6 microspheres was almost 2.26 times that by pristine Bi2MoO6 under simulated solar light. 4C-Bi2MoO6 microspheres (0.2 g/L) presented excellent photocatalytic performance toward RhB (20 mg/L) at pH value 1 and could remove 98.31% of the RhB within 120 min. In addition, 4C-Bi2MoO6 microspheres also possessed a high photocatalytic activity toward methylene blue and tetracycline. 4C-Bi2MoO6 microspheres assembled from thin nanosheets can be used as effective photocatalysts to degrade toxic organic molecules from wastewater.

Facile synthesis of CuO-Ag2O hybrid metal oxide composite using carica papaya, cocooning with hydroxyapatite, and photocatalytic degradation of organic dyes

The synthetic strategy of mixed metal oxide nanoparticle has emerged to be one of the interesting domains in material science. Here carica papya fruit extract assisted synthesis of silver copper oxide is reported via co precipitation method. For the comparative study, using similar precursor material silver copper mixture composite is synthesized using conventional base via coprecipitation method. The composites were subjected to degradation of methylene blue for observation of its efficiency as a photocatalyst. Hydroxyapatite was obtained from fish bones and was used for encapsulating the composite material. The resultant composite was analysed using XRD, SEM-EDS, TEM, XPS and FT-IR techniques. The uncapped composites reported to degrade 90.12 % and 91.5 % of methylene blue within 60 min. The conventionally synthesized composite degraded 30 ppm Bibersch scarlet up to 86.04 % in 40 min under assistance of sunlight. The encapsulated composite was successful in degradation of Brilliant green 89.9 % in 140 min and eosin yellow 92.2 % in 120 min. The catalyst in encapsulated and un encapsulated form reveals its efficiency to be a potential photo catalyst.

Fabrication of MoS2 restrained magnetic chitosan polysaccharide composite for the photocatalytic degradation of organic dyes

Chitosan (CS) polysaccharide is expected to exhibit greater ionic conductivity, which can be attributed to its increased amino group content when it is blended with different semiconducting materials. Herein, the work used this conducting ability of chitosan and prepared a heterogeneous MoS2-induced magnetic chitosan (MF@CS) composite via the co-precipitation method, which was used to scrutinize the catalytic performance with Methylene Blue (MB) and Malachite Green (MG) dyes by visible light irradiation. The saturation magnetization value of the MF@CS composite is found to be 7.8 emu/g, which is less when compared to that of pristine Fe3O4 (55.7 emu/g) particles. The bandgap of the MF@CS composite is ∼ 2.17eV, which exceeds the bandgap (Eg) of bare MoS2 of 1.80 eV. The maximum color removal of 96.3 % and 93.4 % for MB and MG dyestuffs is recognized in the exposure of the visible spectrum, respectively. At a starting dye dosage of 30 mg/L, 0.1 g/L of MF@CS, a pH level of 8−11, and 70 min of contact with direct light. The photocatalyst provides extremely good durability for a maximum of five phases. Hence, the MF@CS matrix is a viable and appropriate substance for the efficient treatment of effluents containing dye molecules.

Photocatalytic degradation of textile dye with titanium (IV) doped tungsten oxide nanoparticles

Water pollution from textile industries is a major concern with respect to the availability of clean drinking water. The removal of textile (organic) dyes through photocatalytic degradation with pure WO3 and titanium (IV) doped tungsten oxide [Ti (IV)-WO3] nanospheres were studied under visible light. The WO3 and Ti (IV)-WO3 nanospheres were synthesized via microwave-assisted method at microwave power of 160 W for the duration of 20 mins. The as synthesised WO3 and Ti (IV)-WO3 nanospheres were characterized for their structural, microstructural, and spectroscopic properties by using powder X-ray diffraction (XRD), UV–Visible (UV-Vis) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and High-resolution transmission electron microscopy (HR-TEM). The X-ray diffractograms confirmed the formation of highly pure WO3 and Ti (IV)-WO3 nanospheres. The average crystallite size of WO3 and Ti (IV)-WO3 nanospheres were calculated as 53.37 nm and 35.24 nm respectively using Debye Scherrer equation. The bandgap of Ti (IV)-WO3 was found to be decreased to 2.5 eV from 3.2 eV (WO3) respectively. It can be deduced that Ti (IV)-WO3 can be utilized as efficient visible light (λ>420 nm) driven photocatalyst as the bandgap was < 3 eV. The agglomerated spherical nanoparticles were seen for WO3 and Ti (IV)-WO3 in the HR-TEM images. The photocatalytic activity of textile dye was analyzed by UV-Vis spectrophotometer under visible light. The photocatalytic organic dye degradation was investigated. The enhanced photocatalytic activity of titanium (IV) doped tungsten oxide (10 wt%) was observed to be ~100% in 100 mins. This makes titanium (IV) doped tungsten oxide nanospheres, a potential nanomaterial for water purification.

Complementary metalloporphyrin-based nanostructure decorated with silver nanoparticles for photocatalytic degradation of organic dyes

A hybrid composite photocatalyst, SA-T@Ag, was fabricated by the photoreduction of silver salts in the presence of nanomaterials composed of self-assembled complementary porphyrin triad SA-T. We confirmed the formation of SA-T@Ag from SA-T using various spectroscopic techniques, including X-ray diffraction (XRD), infrared (IR) spectroscopy, UV–visible spectroscopy, and fluorescence spectroscopy. Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) investigations revealed that a substantial amount of silver nanoparticles (AgNPs) were deposited on the surface of SA-T and that the microstructure of SA-T was intact during photoreduction. The formation of AgNPs on the surface of SA-T reduced the band gap energy (Eg) of SA-T@Ag compared to that of SA-T. This not only improves its light-harvesting properties but also delays the recombination of photogenerated electron-hole pairs, which promotes more reactivity under visible light irradiation and improves the efficiency of polluted dye degradation. These photophysical properties are reflected in the degradation of methylene blue (MB) dye under visible light irradiation. The first-order degradation rate constant of MB dye within 45 min of visible light irradiation is much higher for SA-T@Ag (0.081 min−1) than SA-T (0.028 min−1). This report is of great importance in the field of environmental remediation and provides new opportunities for designing porphyrin-based photocatalytic systems as alternatives to conventional photocatalysts.

Cadmium (II) metal–organic architecture based on versatile multi‐N‐donor “3,5‐diaminotriazole” and dicarboxylate spacer: Synthesis, crystal structure, and its photocatalytic degradation of organic dye

Herein, we have designed polyfunctional materials of d10‐configuration Cd (II) “Cd‐CP.” The coordination polymer Cd‐CP was synthesized using benzene‐1,4‐dicarboxylic acid and 3,5‐diaminotriazole via solvothermal reaction. The Cd‐CP has been fully characterized by using single X‐ray crystallography, thermogravimetric analysis (TGA), Fourier transform–infrared (FT‐IR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), powder X‐ray diffraction (PXRD), and Brunauer–Emmett–Teller (BET) analysis. Single crystal X‐ray crystallography revealed that the CP‐Cd crystallized in triclinic space group P – 1 with the chemical composition [(BDC)(DAT)2Cd2Cl] (CH3)2 NH2+ · H2O. The present study investigated the impact of different reaction parameters, including the concentration of MG, the dosage of catalyst, and the duration of irradiation, on the outcome demonstrating a high level of photocatalytic efficacy at 99.19% under visible light irradiation. The obtained kinetic data exhibited conformity with a pseudo‐first‐order model, indicating that the rate‐determining step is likely to be photo‐absorption. The value of the apparent rate constant was found to be 0.019 min−1 for 50 mg L−1, 0.016 min−1 for 100 mg L−1, and 0.015 min−1 for 150 mg L−1 MG concentration. The corresponding half‐life time was found to be 36.44, 43.31, and 46.20 min with values of correlation coefficient (R2) as 0.99, 0.93, and 0.98, respectively. Moreover, a trapping experiment was conducted to demonstrate that hydroxy radicals (•OH) are the principal reactive oxygen species (ROS) responsible for the degradation of MG. The results of the total organic carbon (TOC) study indicated a mineralization value of around 89%, suggesting that the dye has been completely degraded into non‐toxic by‐products such as carbon dioxide (CO2) and water (H2O).

Preparation of fluorinated zirconia doped with tin oxide nanocomposites for photocatalytic degradation of organic dyes in contaminated water bodies

Abstract In this study, a novel SnO2–Zr–F nanostructured composite was successfully synthesized through a mild chemical reaction. The crystalline nature of the composite was characterized using XRD, revealing an average crystalline size of 28.31 nm. FE-SEM images illustrated an agglomerated spherical morphology with appropriate elemental ratios. The optical properties of the nanocomposite are identified by UV–vis spectroscopy with Tauc plot, and the calculated bandgap is 2 eV. Photocatalytic activity was assessed against cationic (Rhodamine B) and anionic (Eosin yellow) dyes under sunlight for 150 min, resulting in a maximum degradation efficiency of 92 % and 98 %, respectively. Furthermore, the antibacterial performance of the composite was evaluated against S. aureus and E. coli bacteria. The findings suggest that the prepared nanocomposite exhibits promising potential for environmental applications, showcasing its efficacy in both photocatalytic and antibacterial domains.

Ni, Co-Embedded MOF-Derived N-Doped Bimetallic Porous Carbon for Adsorption-Photocatalytic Degradation of Organic Dyes and Antibiotics.

An efficient protocol for photocatalytic degradation of organic dyes and antibiotics has been successfully established via MOF-derived (MOF = metal-organic framework) Ni, Co-embedded N-doped bimetallic porous carbon nanocomposites (NiCo/NC). Such a NiCo/NC nanocomposite features well-distributed structures, suitable specific surface areas, and more active sites determined by various characterization analyses. The catalyst exhibits higher photocatalytic performance and stability toward the liquid-phase degradation of methylene blue (MB) under visible light irradiation for 60 min, after the adsorption-desorption equilibrium and the thorough degradation into H2O and CO2. Radical quenching experiments further confirmed the dominant effect of electron holes h+ and superoxide radical anions ·O2- for the MB photodegradation process. NiCo/NC was also appropriate for the degradation of Rhodamine B, methyl orange, tetracycline hydrochloride, and norfloxacin. Moreover, NiCo/NC is robust, and its photocatalytic activity is basically maintained after 8 cycles. This work is expected to provide additional information for the design of MOF-derived carbon material with more excellent properties and lay the foundation for further industrial applications.

Facile bio-inspired synthesis of polysaccharide-mediated zinc oxide nanoparticles and their efficient antimicrobial and photocatalytic activity

BackgroundGreen synthesis for nanomaterials, an eco-friendly and sustainable technology, has gained prominence in recent decades, especially in dye removal. The widespread use of toxic organic dyes in various industries has become a significant concern for human health, mainly when these dyes contaminate wastewater. This current study focuses on the prevalent use of hazardous dyes, known for their ecotoxicity, and the challenge of effectively removing these pollutants from wastewater. AimThe primary goal is to achieve a bio-inspired synthesis of zinc oxide nanoparticles using polysaccharides as mediators. This synthesis is designed to enhance the antimicrobial attributes of the nanoparticles and facilitate the photocatalytic degradation of organic dyes. Notably, polysaccharides serve a dual purpose as both a reducing and stabilizing agent for synthesizing ZnO nanoparticles. Significant findingsThe XRD distinctive lattice pattern peaks, such as (1 0 0), (0 0 2), and (1 0 1), affirmed the pure formation of the ZnO structure with a hexagonal wurtzite crystal structure. The chemical composition and product purity of green-produced SB-ZnO NPs were assessed through SEM and XPS analysis. The study then utilized polymer-mediated green-synthesized ZnO NPs for the photocatalytic degradation of Congo red and crystal violet under visible light irradiation. The results demonstrated remarkable photocatalytic activity, with around 88.2% of Congo red dye degradation observed within 80 min of visible light exposure. Notably, Congo red exhibited higher catalytic efficiency compared to crystal violet dye. The antimicrobial activity of SB-ZnO NPs obtained through green synthesis was also investigated. The antimicrobial study revealed the formation of zones against both gram-positive and gram-negative bacterial pathogens. These bioassay metal oxides are recognized for their potential in environmental remediation due to their low cost, stability, efficiency, and minimal environmental impact. The enhanced photocatalytic efficiency of polymer-metal nanocomposites shows significant potential in propelling the utilization of photocatalysts for environmental applications, specifically in wastewater treatment and bactericidal processes.