Photodegradation Of Dye Research Articles

A maghemite (γ-Fe2O3) incorporated activated carbon photocatalytic nanocomposite fabricated via Co-precipitation utilized against degradation of methyl orange

The γ−Fe2O3/ACP has been synthesized in different ratios by facile co-precipitation method to degrade the methyl orange dye. In order to check the stability and potential of photo activated catalyst, UV, PL, SEM, XRD, EDX, FTIR and Zeta Potential are discussed here. The bandgap has been reduced from 2.06 eV to 1.86eV. Here, 1:3 γ−Fe2O3/ACP sample showed maximum reduced bandgap of 1.86 eV. The PL spectroscopy showed that 1:3 sample has less intensity, which in turn have 94 % photo degradation of methyl orange dye in 180min. The 1:3 sample showed 87 % degradation of methyl blue dye at 125mins light irradiation and proved as an optimal concentration of ACP in maghemite at pH of 11. The inclusion of carbon into maghemite enhances the overall properties by reducing the charge recombination rate. No impurity has been found in the final synthesized samples confirmed through EDX. The XRD and SEM revealed that size of crystallites and particle size increases, which confirms that bandgap is reduced. While trapping techniques and recycling techniques has been employed on the optimal concentration sample to check its stability towards degradation of methyl orange (MO) dye. The photo catalysis through such nanocomposite is not reported before. The 1:3 sample showed promising potential towards pollutants degradation in waste water treatment.

Efficient photodegradation of methylene blue dye using cerium-doped titanium dioxide (Ce@TiO2) photocatalyst under visible light irradiation

Water pollution is one of the important threats nowadays, to meet the difficulties several studies are being processed. This work aims to improve water quality by breaking dye components from the waste effluents of textile industries. Methylene blue (MB) widely used textile colorant brings several health issues to all living categories aquatic and terrestrial, including humans. All new syntheses of Cerium-doped Titanium dioxide (Ce@TiO2) nanoparticles have been achieved and proven to be a super-efficient photocatalyst for the photodegradation of MB in wastewater samples. This photocatalyst was prepared using the sol-gel technique without any hazardous chemicals in moderate conditions. The formation of Ce@TiO2 is confirmed by different characterization using XRD, FTIR, SEM-EDS, and HR-TEM analysis. The photocatalytic efficiency of Ce@TiO2 photocatalyst is carried out with varying parameters such as pH, contact time, photocatalyst dose, and MB concentration. Ce@TiO2 is an effective photocatalyst for MB degradation from wastewater at optimized conditions with 92 % removal within 90 min of reaction time. The degradation kinetics follow a pseudo-first-order model, with a rate constant (K) of 0.027min−1, while achieving a remarkable total organic carbon elimination of over 90.0 %. Furthermore, the reusability test showcased the remarkable stability of Ce@TiO2 over four cycles, with only a minor decline (<8 %) observed in MB degradation efficiency.

Optimization Photodegradation of Methylene Blue Dye using Bentonite/PDA/Fe3O4@CuO Composite by Response Surface Methodology

This study aims to synthesize bentonite/PDA/Fe3O4@CuO composites as a catalyst for the photodegradation of Methylene blue dye. Composite characterization involves X-ray Diffractometry (XRD), Scanning Electron Microscopy (SEM) with X-ray Energy Dispersion Spectrometry (EDS), UV-Vis Diffuse Reflectance Spectroscopy (UV-Vis DRS), and Vibrating Sample Magnetometer (VSM). Response Surface Methodology (RSM) employs Central Composite Design (CCD) to optimize photodegradation by varying dye concentration, irradiation time, and catalyst dose. The bentonite/PDA/Fe3O4@CuO composites exhibit a saturation magnetization value of 54.82 emu/g and a band gap of 2.1 eV. The optimization revealed that concentration and dose significantly impact the photodegradation efficiency. A quadratic model is suitable for modeling the photodegradation of Methylene blue dye using bentonite/PDA/Fe3O4@CuO composites, as determined by analysis of variance (ANOVA). The optimal conditions for achieving maximum photodegradation efficiency were identified as a dye concentration of 10 mg/L, an exposure time of 90 min, and a catalyst dose of 1.67 g/L. Under these parameters, the photodegradation process exhibited a remarkable efficiency of 100%. The Bentonite/PDA/Fe3O4@CuO composites exhibited strong stability, efficiency, and recyclability. After six photodegradation cycles, there was a 5.18% decrease in photodegradation efficiency. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Investigation into the impact of anionic substitution on modulating the optical and catalytic properties of bismuth ferrite nanoparticles

Bismuth ferrite (BFO) nanoparticles have emerged as a non-toxic catalyst with remarkable potential for the photodegradation of various environmental pollutants. A notable departure from conventional approaches, where cations are added as dopant, this study achieved enhanced catalytic performance through anion substitution. Specifically, replacing oxygen atoms with nitrogen introduces spin-polarized defect states within the BFO’s energy gap, resulting in a notable reduction in the energy band gap. Nitrogen doping of bismuth ferrite yields a novel material with exceptional capabilities for the photodegradation of methylene blue dye and the reduction of 4-nitrophenol. Comprehensive characterization, including X-ray diffraction, Fourier-transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy, has unequivocally confirmed the successful incorporation of nitrogen into the BFO nanoparticle lattice. Interestingly, field emission scanning electron microscopy analysis revealed no significant alteration in nanoparticle size after nitrogen doping. Meanwhile, UV-diffuse reflectance spectroscopy unveiled a distinct decrease in the energy gap upon nitrogen incorporation. The observed improvements in catalytic activities can be attributed to nitrogen ions, introduced as substitutes, effectively occupying the oxygen defects within the sample, thereby diminishing recombination centers for photogenerated charge carriers and decreasing recombination rates. Additionally, adsorption kinetics studies underscore the efficacy of the catalyst surface in adsorbing methylene blue and/or 4-nitrophenol, conforming to the Ho pseudo-second-order model. This study not only highlights the exciting potential of nitrogen-doped bismuth ferrite nanoparticles in environmental remediation but also sheds light on the intricate interplay between anion substitution, band structure modification, and catalytic performance enhancement.Graphical

Sol Gel obtained Ti/Co/Mn oxides doped with 5wt% CuO for the photocatalytic removal of organic azo dyes from wastewater

Various organic pollutants continually poison natural water resources due to rapid modernization driven by industrial growth. As a result, communities throughout the globe are paying close attention to the health and environmental issues raised by these harmful organic pollutants. Here, we prepared TiO2-CuO(5wt%), TiO2-CuO(5wt%)@Co3O4, and TiO2-CuO(5wt%)@Mn2O3 photocatalysts by employing the sol-gel method for the photocatalytic removal of azo dyes. These composites' surface morphology, composition, band gap, and purity were analyzed using SEM, EDS, TEM/HRTEM, XRD, FTIR, Raman, XPS, DRS, and BET measurements. The 5 % CuO doping caused a significant change in the electronic structure of the composites and contributed to the superior photocatalytic performance of the composites against azo dyes at neutral pH and under visible light irradiation. The function of reactive oxygen species (ROS) was also studied using different scavengers and enhancers; •OH was found to be the main ROS for the photodegradation of azo dyes.

Photocatalytic performance of Soot/TiO2 nanocomposite against toxic dye

Nowadays, composing semiconductors with carbon structures to enhance their optical properties shows huge interest as a nanophotocatalyst for trending applications (i.e., photodegrading pollutants). In this study, TiO2 and soot/TiO2 nanocomposites were prepared via a one-step sol-gel assisted hydrothermal method, using a temperature of 220 °C and a reaction time of 6 h. Characterization by X-ray diffraction and Raman spectroscopy confirmed that the resulting TiO2 and soot/TiO2 materials exhibited a pure anatase crystal phase, without the presence of other TiO2 polymorphs. Soot composition on TiO2 showed enhanced photocatalysis properties, such as a lower combination rate of electron-hole pairs than pure TiO2. Crystal violet (CV) was applied as a pollutant model to examine the photocatalytic degradation of synthesized TiO2 and soot/TiO2. The photodegradation experiments of CV dye in its aqueous media by UV light interaction showed 26.63 % and 89.09 % in the presence of TiO2 and soot/TiO2 nanocomposite, respectively. In the basic media (pH 11), maximum photodegradation (97.95 %) is attained when 0.004 g of Photocatalyst (soot/TiO2) is used. Using the recycled photocatalyst, the dye's photodegradation efficiency remained high throughout the reusability cycles, even after four consecutive cycles.

Ultrasonic assisted synthesis of nanoporous carbon/CeVO4 nanocomposite for supercapacitor and photocatalytic applications

Here, nanoporous carbon (NPC)/CeVO4 nanocomposite synthesized via ultrasonic assisted method for supercapacitor and tartrazine dye degradation application. Transmission electron microscope (TEM) studies confirmed the CeVO4 nanoparticles well embedded on the NPC surface in the NPC/CeVO4 nanocomposite. Spherical shaped CeVO4 nanoparticles are well incorporated on the surface of NPC therefore NPC/CeVO4 nanocomposite which possess a porous-like structure would improve the supercapacitor applications and dye degradation performance. As expected, the specific capacitance (Cs) values (555 F g−1) of NPC/CeVO4 nanocomposite showed enhanced performance as compared to CeVO4 nanoparticles (234 F g−1) at a current density of 1 A g−1 and the capacitance retention of the designed electrode as 95 % after 5000 cycles. The photodegradation of tartrazine dye using pure CeVO4 nanoparticles and NPC/CeVO4 nanocomposite was explored under visible light irradiation. The photocatalytic degradation experiment demonstrated that the NPC/CeVO4 exhibits the maximum degradation efficiency (98.76 %) of the tartrazine with was reached within 120 min. Moreover, the rate constant of NPC/CeVO4 for tartrazine dyes decomposition was 0.0192 min−1 representing that it is two-fold higher than pure CeVO4 (0.0073 min−1). The superior electrochemical and photocatalytic properties of NPC/CeVO4 nanocomposite have been observed due to the well-designed structure and high surface area. Consequently, as-prepared NPC/CeVO4 material could be a promising material for electrochemical supercapacitor and dye degradation of the tartrazine organic pollutant.

Insights for Precursors Influence on the Solar-Assisted Photocatalysis of Greenly Synthesizing Zinc Oxide NPs towards Fast and Durable Wastewater Detoxification

Herein, this study has examined the influence of Zn2+ sources during a biogenic-mediated pathway to synthesize ZnO nanoparticles with highly desirable solar-responsive catalytic properties. Salts of nitrate, acetate and chloride have been utilized. The ZnO powders underwent characterization using diverse analytical tools, including XRD, FTIR, Raman, BET, SEM, TEM with EDS/elemental mapping and UV-vis absorption/emission spectroscopic analyses. Accordingly, precursors have proved to affect crystallinity, morphology, surface characteristics, optical properties and the photocatalytic degradation of methylene blue (MB) model pollutant. It was observed that ZnO derived from zinc acetate precursor (Z-AC NPs) exhibits very fast photocatalytic degradation of MB at pH 11 with superior kinetic estimates of 0.314 min−1 and t1/2 = 2.2 min over many of recent reports. In contrast, the chloride precursor is not recommended along with the employed biogenic route. The intriguing findings could be directly correlated to the decreased crystal size, augmented surface area, the hexagonal morphology of the crystals, high potency in absorbing visible photons, high efficacy in separating photogenerated charge carriers and producing high amounts of •OH radicals. Further testing of Z-AC NPs in photocatalytic remediation of water samples from Dumat Aljandal Lake in Aljouf, Saudi Arabia, contaminated with MB and pyronine Y (PY) dyestuffs, showed high dye photodegradation. Therefore, this work could lead to an extremely fast avenue for decontaminating wastewater from hazmat dyestuff.

3D-printed MOF/MoS2 aerogel for dye adsorption and photocatalytic degradation

The escalating challenge of water resources contamination, attributed to toxic pollutants, requires urgent attention from both governments and society. Furthermore, the inefficacy of conventional water treatment methods emphasizes the critical necessity for exploring the development of affordable, renewable, and high-performance materials, which should, for instance, enable the mutual adsorption and photocatalytic degradation of organic pollutants. Here we employed the 3D printing technique to manufacture an aerogel based on alginate, gelatin, and carboxymethylcellulose incorporated with 5 and 7.5 wt % of MOF/MoS2. FTIR spectra and EDS analysis evidenced the presence of MOF/MoS2 in the structure of the aerogels, while Helium pycnometer analysis and SEM micrographs demonstrated that the aerogels presented low density and a porous structure with porosity above 80 %. The swelling test showed that the aerogels displayed a high water absorption capacity (1400 %) after 70 h of immersion. The rheology test demonstrated that elastic behavior prevails over viscous behavior (G' > G″) and the incorporation of 7.5 wt % MOF/MoS2 favored shear thinning and viscosity recovery in the hydrogel. Adsorption tests to methylene blue (employed as a model) showed that the aerogel (HD) without the presence of MOF/MoS2 and the aerogels HD/MOF/MoS2 5 % and MOF/MoS2 7.5 % showed removal efficiencies of 16.77 %, 28.66 %, and 95.86 %, respectively. Conversely, the photodegradation test showed that HD/MOF/MoS2 5 % and HD/MOF/MoS2 7.5 % had an efficiency of 89 % and HD of 80 %. Therefore, our results demonstrate that the developed aerogels are promising candidates for the adsorption and photodegradation of dye while being low-cost, environmentally friendly, and easy to manufacture.

Green Synthesis of carbon quantum dots for enhancing photocatalytic activity: Hydrogen/oxygen evolution and dye photodegradation

Carbon quantum dots (CQDs) have recently attracted attention across various fields due to their small size, high conductivity, fluorescence emission, low toxicity, and other desirable characteristics. In this study, highly fluorescent CQDs with an average diameter of 3.7 nm were prepared via microwave irradiation using a standard commercial microwave oven and glycerol as solvent. Several cation promoters were examined for CQD synthesis, with copper ions ultimately chosen for comprehensive characterization and application. The CQDs were impregnated onto both commercially available and microwave-synthesized TiO2 nanoparticles. The photocatalytic activity was evaluated with respect to the hydrogen and oxygen generation. Under the employed conditions, the oxygen evolution reaction (OER) exhibited over 12 times higher efficiency than the hydrogen evolution reaction (HER). The enhanced OER activity is attributed to the high electronic conductivity of the small Cu doped CQDs@TiO2 (Cu-CQDs@TiO2) facilitating an efficient electron transfer for the OER . Visible light activity (λ ≥ 400 nm) was demonstrated by photodegradation of the indigo carmine (IC) solution used as a model pollutant. Irradiation in the presence of the Cu-CQDs@TiO2 photocatalyst resulted in complete degradation of the dye in less than 3 hours. The results presented here provide a promising methodology for designing high-performance photocatalysts based on environmentally friendly CQD syntheses. Crucial applications, from renewable energy production to environmental remediation, will benefit from strategies using the carbon abundance on Earth.

Photocatalytic removal of organic dyes mediated by p-NiO/p-CuO isotype heterojunctions under sunlight illumination

Building heterojunctions between different semiconductors is one of the most typical approaches to separating photo-induced electrons and holes in order to enhance photocatalytic efficiency. In this study, NiO, CuO, and NiO–CuO nanocomposites thin films are obtained under the same deposition conditions by a simple spray pyrolysis technique. The structural, morphological, and optical properties of the deposited thin films were investigated using different techniques such as XRD, Raman, SEM, EDX, PL, and UV–visible spectroscopy. XRD and Raman analysis revealed that NiO, CuO, and NiO–CuO have crystalline cubic, monoclinic, and mixed phases, respectively. EDX analysis confirmed the chemical composition, and SEM images reveal different morphologies depending on the Ni:Cu molar ratio. The photodegradation of MB dye in the presence of the thin films was examined under sunlight. Compared with individual metal oxides, NiO–CuO nanocomposites are better as photocatalysts. Optical measurements were able to connect these enhanced photocatalytic activities to the synergistic effects of combining NiO and CuO, which promoted the creation of defects and highly reactive species on surfaces and an effective separation of photogenerated charges. The benefits of p-p isotype heterojunctions for dye photodegradation that this study has illustrated provide a novel perspective on metal oxydes-based nanocomposites for the development of efficient and novel photocatalysts.

Hydrothermal synthesis of CoSnO3 nanocubes-incorporated graphitic carbon nitride for the efficient photodegradation of organic dye and antibiotic drug

In this work, an eco-friendly, low-cost, facile synthesis of CoSnO3/g-C3N4 using an in-situ hydrothermal method by incorporating graphitic carbon nanosheets. In as-prepared nanocomposite, the CoSnO3 nano cubes strongly attached to graphitic carbon nanosheets due to the ionic interaction which leads to improved catalytic activity, conductivity and stability. The as-synthesized nanocomposite was characterized by various spectral, structural and optical studies and it was applied for the photocatalytic degradation of organic dye-methylene blue (MB) and antibiotic drug-norfloxacin (NOR). From DRS-UV analysis, CoSnO3 exhibit a bandgap of 2.93 eV, g-C3N4 and CoSnO3/g-C3N4 has 2.84 eV and 1.95 eV, respectively. The nanocomposite demonstrates admirable degradation efficiency of 95.24 % for Methylene blue within 50-min and 95.99 % for Norfloxacin within a 70-min period under visible-light active conditions and surpass the performance of pure CoSnO3 and g-C3N4 due to the synergetic acceleration of heterojunction. The results have demonstrated that the CoSnO3/g-C3N4 nanocomposite exhibits significant potential as a photocatalyst for the degrading NOR antibiotic and MB dye. Liquid chromatography–mass spectrometry (LC-MS) analysis identified four potential routes for the degradation intermediates of norfloxacin. Moreover, the nanocomposite material exhibits long term stability, durability and good bio comfortability.

Dual-function CoNi-LDH hollow porous spheres for morphology-driven adsorptive removal and photo-oxidative degradation of anionic dyes

The layered double hydroxides (LDHs) emerged as a class of low-cost potential adsorbents for organic pollutant separation, whereas the deep study of organic dye separation regulated by LDH hollow morphology under ambient conditions is still lacking. To address this gap, ZIF-67, Bulk-CoNi-LDH, and HPS-CoNi-LDH materials of different morphology and porosity were synthesized and investigated in the dye separation process. Methyl orange (MO), congo-red (CR), methylene blue (MB), and rhodamine B (Rhb) dyes were selected as model dye pollutants. The spectroscopic and structural analysis reveals the HPS-CoNi-LDH exhibits less-aggregated 2D nanosheets, high BET surface area of 163.2 m2/g, large pore size of 12.29 nm, greater positive surface charges (27.5 mV), superior optical (2.18 eV), and charge-separation capabilities as compared to Bulk-CoNi-LDH, Which provides potential sites for adsorptive and photo-degradation for anionic dyes under natural sunlight. Therefore, it achieves a remarkable removal efficiency of 92.6% for methyl orange (15 ppm) with a superior kinetic rate of 3.0×10−2 min−1 within 90 min, outperforming Bulk-CoNi-LDH and ZIF-67 having removal efficiency of 71.7% and 40.8%, and kinetic rate of 1.35×10−2 and 0.5×10−2 min−1, respectively. Poor removal efficiency and kinetic by ZIF-67 was mainly due to its smaller pore size (1.16 nm) and surface-confined charges (6.13 mV). Additionally, HPS-CoNi-LDH exhibits superb selectivity (at a ppm level) and excellent recyclability under ambient conditions. The mechanism of photo-catalytic reaction is discussed. These results delineate the hollow morphological LDH structure could be a worthy candidate for selective wastewater treatment and useful for sustainable conditions, which points the way to other crucial anionic micropollutant remediation.

Easy Scalable Solid-State Synthesis of Highly Efficient Synergetic 2D/1D Micro/Nanostructured g-C3N4/MeS (Me=Cd, Mo) Photocatalysts for Organic Dye Degradation and Hydrogen Evolution

The global reserves of oil, gas, and coal are acknowledged finite, and their consumption rates are increasing each year [1]. Following Fujishima’s groundbreaking discovery of photocatalytic water splitting using TiO2 electrodes in 1972 [2], photocatalysis technology gained recognition as a promising approach for renewable energy and environmental conservation [3]. Since that pivotal moment, significant advancements have been made in developing preparation methods for highly efficient photocatalysts, predominantly centered on semiconductors like metal oxides and sulfides [4].In this study, we introduce effective synergistic photocatalysts, that utilize g-C3N4 and MeS (Me=Cd, Mo) semiconductors featuring a 2D/1D micro/nanostructure. Photocatalysts were successfully produced through solid-state method using planetary ball mill, where reaction of MeS formation occurs on the surface of g-C3N4. A comprehensive analysis of the binding energy of electrons of semiconductors was conducted to understand its impact on the photocatalytic activity of the prepared g-C3N4/MeS. The fabricated materials were used in the photodegradation of organic dyes and demonstrated remarkable efficacy. Regarding photocatalytic hydrogen evolution, the g-C3N4/CdS in conjunction with Pt co-catalyst, achieved a hydrogen evolution rate of up to 2254.54 μmol*h⁻¹ *g⁻¹, accompanied by apparent quantum efficiency of 2.0%. Acknowledgments This research was funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. АР13068426).

Green synthesis of Fe[sbnd]Ni[sbnd]Sn trimetallic oxides from Moringa oleifera for photocatalytic degradation of Reactive Red 6B dye

The nanocomposite FeNiSn trimetallic oxides were synthesized using an aqueous Moringa Oleifera leaf extract. The prepared nanocomposite was analyzed using SEM, FTIR, XRD, N2 adsorption-desorption, Zeta potential, and UV–vis analysis. A common Azo dye named Reactive Red 6B (RR-6B), widely applied in the dyeing industry and causing environmental pollution, was selected to examine the photodegradation of FeNiSn trimetallic oxides nanocomposite under sunlight irradiation, and it was shown that this dye could be successfully degraded by prepared nanocomposite. Effects of parameters such as inorganic salt concentration, H2O2 concentration, contact time, pH, and impact of different concentrations of catalyst and dye were examined to find out degradation conditions. This prepared nanocomposite was applied for the photodegradation of RR-6B dye, and 95 % degradation efficiency was obtained at pH 4, 10 mg of catalyst concentration, 10 ppm of dye concentration, and contact time of 2 h. Degradation kinetics were carried out using Langmuir-Hinshelwood and first-order reaction models. These results showed a facile technique for forming nanocomposite to efficiently degrade organic contaminants from wastewater, which directly impacts industrial wastewater treatment. The antibacterial activity was performed using the Time assay kill method for Gram-positive S. aureus and Gram-negative E. coli bacteria. The results of antibacterial activity showed an inhibition effect on bacterial growth by trimetallic oxides NPs, suggesting their potential use in antimicrobial coatings and materials. These findings underscore the practical applications of our research, demonstrating its relevance and potential impact in real-world scenarios.

Self-sensitized photodegradation and adsorption of aqueous malachite green dye using one-dimensional titanium oxide nanofilaments

Truly one-dimensional titanium oxide nanofilaments with a lepidocrocite structure (1DLs) were explored in the adsorption and photocatalytic degradation of aqueous malachite green (MG), a toxic polluting dye. Decolorization is monitored by ultraviolet-visible spectroscopy, and mineralization is confirmed by total organic carbon analysis. The 1DL/MG flocs are characterized by scanning electron microscopy and X-ray diffraction. 1DLs, a colloidal nanomaterial, exhibit flocculating behavior while demonstrating high affinity for MG, with a maximum uptake of >680mg/g rapidly via ion exchange. Additionally, 1DLs decolorize MG under visible light only, unlike most available titania products, via a self-sensitization effect. MG is decolorized by 1DLs by >70% in 30min under 1 sun exposure of visible light. Counterintuitively, dye adsorption increases as the normalized concentration by mass of 1DL decreases. Demonstrating high adsorption capacity and dye mineralization supports the use of 1DLs in water treatment and self-sensitization for photoelectrochemical devices, like solar cells.

One-step synthesis of versatile PbMoO4@CdMoO4 microspheres hybrid for the enhanced photocatalytic dye degradation

In this work, we have demonstrated the productive synthesis of novel and versatile CdMoO4@PbMoO4 microspheres hybrid photocatalysts by a simple chemical reduction process. Fabricated CdMoO4@PbMoO4 hybrid microsphere characteristics were analyzed by various techniques to ascertain their structural and morphological properties. The photocatalytic degradation properties of CdMoO4@PbMoO4 hybrid microspheres were evaluated against methylene blue (MB) and congo red (CR) colorants under visible light. The hierarchical structure of CdMoO4@PbMoO4 along with the modulated bandgap, interfacial valence state electrons shift, and quick conversion of the Cd2+/Pb2+ cycle led to the display of the 98 % and 97 % degradations of CR and MB under visible light treatment, respectively which is superior to the corresponding pure structures degradation efficiency, signifying their boosted catalytic properties. Furthermore, the degradation mechanism endorsed excellent dye photodegradation under visible light illumination by the novel CdMoO4@PbMoO4 microspheres hybrid catalyst. The observations gave more insight into the progress of the advancement of CdMoO4@PbMoO4 microspheres hybrid to effectively detoxify perilous and toxic water effluents for industrial purposes.

Fabrication of CuO/MoS2@gCN nanocomposite for effective degradation of methyl orange and phenol photocatalytically

Water from the industries contains various organic effluents which are needed to be removed. Photocatalysis is an efficient method to degrade organic effluents that contaminate water and harmfully affect the environment. This study presents the structural, optical characteristics, and photocatalytic activity of the CuO/MoS2 and their composite with gCN. The hydrothermal approach was employed to fabricate MoS2 nanoflowers, and the co-precipitation method to fabricate CuO. The composite with gCN was prepared successfully using an ultrasonication approach. The physio-chemical properties of fabricated photocatalysts were investigated by various characterization techniques. SEM analysis revealed the nanoflower morphology of the prepared MoS2 sample. The photocatalytic activity was examined by the photodegradation of methyl orange dye and phenol. CuO/MoS2@gCN photocatalyst showed 85.14 % degradation of methyl orange and 63.50 % degradation of phenol. Also, the rate constant of CuO/MoS2@gCN was found to be 0.051 min−1 for MO dye and 0.02 min−1 for phenol, which is higher than other synthesized samples. The scavenging experiment was carried out to identify the most photoactive species involved in the organic pollutants photocatalytic degradation. Electrons served as the primary photoactive species in photocatalysis. Consequently, it is concluded from the results that CuO/MoS2@gCN could be employed as an efficient photocatalyst for wastewater treatment.

Toxic Congo Red Dye Photodegradation Employing Green Synthesis of Zinc Oxide Nanoparticles Using Gum Arabic

Toxic Congo Red Dye Photodegradation Employing Green Synthesis of Zinc Oxide Nanoparticles Using Gum Arabic

Hydrothermal synthesis of carboxylated functionalized jute stick carbon and reduced graphene oxide based ZnO nanocomposite photocatalysts: A comparative study

The advancement of photocatalytic degradation to eliminate toxic organic pollutants from wastewater has progressed rapidly. Although numerous photocatalysts have been reported, there remains a huge demand of appropriate photocatalyst materials that demonstrates remarkable photocatalytic efficiency. The prime target of this study is to explore a new way of fabricating low cost and environmentally friendly carboxylated functionalized jute stick carbon based ZnO photocatalyst for eliminating organic dyes from aqueous solution. In this study, nanostructure semiconductor photocatalyst undecorated ZnO, carboxylated activated jute stick carbon based ZnO (ZnO/JSAC-COO–), and reduced graphene oxide based ZnO (ZnO-rGO) composites were fabricated by a facile low-cost hydrothermal process. The crystallinity, morphology, particle size, chemical characterization and optical properties were characterized by X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Fourier Transform Infrared Spectroscopy (FT-IR), Raman Spectroscopy and UV–visible spectroscopy, respectively. The XRD results showed that all XRD patterns of photocatalyst have a wurtzite, hexagonal structure of ZnO without any impurities. The catalytic activities of fabricated samples were examined by the photodegradation of methylene blue dye in water under UV light. The photocatalyst ZnO/JSAC-COO– composite exhibited enhanced photocatalytic activity than ZnO and ZnO-rGO catalysts. The highest degradation and mineralization were obtained 97.57 % for methylene blue over ZnO/JSAC-COO– within 300 min UV light irradiation. Photodegradation results suggest that ZnO/JSAC-COO– composite prepared by hydrothermal method has a potential application in photo-catalysis leading to the efficient removal of harmful organic pollutants from the wastewater.