Photocatalytic Dye Degradation Research Articles

Retraction of “Photocatalytic degradation of organic dyes and biological potentials of biogenic zinc oxide nanoparticles synthesized using the polar extract of Cyperus scariosus R.Br. (Cyperaceae)”

Retraction of “Photocatalytic degradation of organic dyes and biological potentials of biogenic zinc oxide nanoparticles synthesized using the polar extract of <i>Cyperus scariosus</i> R.Br. (Cyperaceae)”

Biodegradable cobalt and tin doped chitosan nanocomposites from structure tailoring to solar-driven photocatalytic degradation of toxic organic dyes.

The primary concern is the large amounts of emitted organic dyes through wastewater from numerous sectors. One of the most hazardous dyes commonly used in the industrial sector is methyl violet. It has been known to cause skin, gastric, and respiratory disorders. Therefore, a novel photocatalyst based on cobalt‑tin sulfide (Co3Sn2S2) was prepared using the solvothermal process. The photocatalyst was supplemented with Chitosan to prepare the cobalt tin sulfide-chitosan composite (Co3Sn2S2/Chi) for the photocatalytic degradation of methyl violet dye. Based on EDX analysis, a definite ratio of tin, cobalt, and sulfide was found. The FTIR of Co3Sn2S2/Chi revealed the characteristic bands of chitosan and metal sulfide bonds. SEM results showed that the particle had an irregular shape. The composite's crystalline structure was identified by XRD analysis as being 56 nm in crystalline size. The photocatalyst had a narrow band gap of 1.02 eV. At ideal conditions, the developed photocatalyst demonstrated greater degradation efficiency of methyl violet dye under solar light irradiation. The photocatalyst successfully decomposed 95 % of the methyl violet dye (40 ppm) within 70 min, operating at a pH of 9.0. This remarkable degradation was achieved by employing 0.25 g of the photocatalyst. The photocatalyst is more appealing and can be reused for up to three successive cycles. The photocatalyst is well-suited for "pseudo-first-order kinetics" to decontaminate methyl violet dye. The novel photocatalyst showed the most robust ability to decolorize methyl violet when exposed to sunlight and was a viable substitute for dye detoxification of organic dyes from wastewater.

Rapid Degradation of Dye Effluents with A SnS Catalyst: A Sustainable Approach Using Natural Light Under Ambient Conditions.

Dye degradation presents a persistent challenge in addressing water pollution. While several methods, including adsorption, biodegradation, and advanced oxidation processes, have been extensively explored, photocatalysis remains one of the most effective techniques. Conventional photocatalytic dye degradation processes often rely on expensive light sources and are time-intensive. Herein, we synthesized a SnS catalyst by the solvated metal atom dispersion (SMAD) method, using Sn foil and sulfur powder. The catalyst exhibited remarkable performance, achieving complete degradation of methylene blue within 2 minutes under ambient room light, without the need for any external light source. Similar degradation efficiency was achieved for methyl orange. To evaluate the role of light for the degradation, control experiments were conducted in the dark using methylene blue as a model dye. Although the degradation rate was slightly reduced, the catalyst still facilitated dye degradation in the absence of light. Additionally, the catalytic performance was tested with four other dyes under natural light, all of which yielded promising results, demonstrating the versatility and effectiveness of the SnS catalyst in dye degradation. This work highlights the potential of the SnS catalyst for efficient and rapid dye degradation under both light and dark conditions, offering an energy-efficient solution for wastewater treatment.

Photocatalytic Dye Degradation with Magnetically Recoverable and Reusable Bismuth Ferrite Nanoparticles

Photocatalytic Dye Degradation with Magnetically Recoverable and Reusable Bismuth Ferrite Nanoparticles

Research on Graphitic Carbon Nitride (g-C3N4) prepared by template-based method and its photocatalytic properties

Abstract. The Graphitic Carbon Nitride (g-C3N4), a non-metallic polymer photocatalytic material, has a wide range of raw materials and a simple preparation process. Due to its unique electronic structure and excellent photocatalytic performance, g-C3N4 has attracted wide attention in the field of environmental purification and energy conversion in recent years. However, g-C3N4 faces a lot of challenges, including a wide band gap, many interlayer defects, and poor interlayer electron transport. Nevertheless, its unique semiconductor structure and chemical stability still provide the possibility to explore the effect of its piezoelectric properties on photocatalysis, which paves the way for a novel approach to environmentally friendly hydrogen production. Therefore, the paper delves into the application of different template methods in the preparation of g-C3N4 by reviewing the related literature, and analyzes the role of different template materials in the preparation. In addition, in this paper, the photocatalytic properties of g-C3N4 are explored, which are mainly reflected in the photocatalytic water separation performance and photocatalytic degradation of organic dyes. It is found that the g-C3N4 shows great potential in the fields of photocatalytic water decomposition for hydrogen production and degradation of organic pollutants due to its unique band gap, nontoxicity, low cost and wide range of sources. Future research should continue to explore more kinds of template materials and their preparation processes, with the aim of realizing further enhancement of the performance of g-C3N4 photocatalysts and promoting their practical applications in the fields of environment and energy.

Comparative analysis of the antimicrobial activity and dye degradation of metal oxides (TiO2, CdO, Mn2O3, and ZnO) nanoparticles using a green approach.

A tremendous amount of recent work has been done on different metal oxide nanomaterials for biological activities and photocatalytic dye degradation. This work used the Cissus quadrangularis leaf extract to prepare TiO2, CdO, Mn2O3, and ZnO nanoparticles using a green synthesis approach. To ascertain the physicochemical characteristics of the generated metal oxide nanoparticles, various characterisation techniques were used. The X-ray diffraction technique was used to determine the composition of the crystal and phase. Metal oxide nanoparticles have been proven to be present through surface morphological investigations using a scanning electron microscope and energy dispersive spectroscopy analysis. UV-Vis and Fourier transform infrared spectra were used for spectroscopic analysis. X-ray photoelectron spectroscopy can determine a material's elemental composition in addition to the electronicand chemicalstates of its atoms. The nanomaterial's distinct morphology, which resembles rods, rose petals, platelets, and spheres, was discovered by scanning electron microscope. Synthesized metal oxide nanoparticles have demonstrated a remarkable efficiency of 87.5-90.6% when utilized as a catalyst towards the removal of the malachite green dye under UV light irradiation. Additionally, we use the disc diffusion method to assess antibiotic efficacy against Bacillus subtilis, Candida tropicalis, and Escherichia coli. ZnO nanoparticles had the greatest zones of inhibition for 80 μL doses, measuring 26.99mm for Bacillus subtilis, 27.57mm for Escherichia coli, and 25.28mm for Candida tropicalis. The antimicrobial activity was strongly impacted by the size of the nanoparticles and increased with decreasing particle size. Overall, our research demonstrates that metal oxide nanoparticles are a promising photocatalytic agent for wastewater treatment and biological applications.

La-supported SnO2–CaO composite catalysts for efficient malachite green degradation under UV–vis light

This study presents the development and optimization of La@SnO2–CaO composite catalysts for efficient photocatalytic degradation of malachite green dye in aqueous solutions under UV–vis light irradiation. The catalysts were prepared via conventional incipient-wetness impregnation and thoroughly characterized using advanced analytical techniques, including X-ray diffraction, Fourier transform infrared spectroscopy, UV–vis diffuse reflectance spectroscopy, N2 adsorption–desorption analysis, and scanning electron microscopy. To optimize photodegradation efficiency, the effects of three independent factors were systematically investigated using response surface methodology: Temperature, pH, and Sn/Ca molar ratio. Our results reveal optimal conditions for maximum dye degradation: pH 7, Sn/Ca molar ratio of 0.33, and a process time of 35 min, resulting in a maximum photodegradation efficiency of 98.80% for malachite green dye. Notably, visible light exhibited a more pronounced effect on dye degradation compared to UV light over time, with visible light achieving 25% greater dye removal after 60 min of illumination. Furthermore, the catalyst showed excellent recyclability, retaining 85% of its initial activity after five consecutive cycles. These findings contribute significantly to the development of sustainable methods for dye removal from wastewater and highlight the potential of La@SnO2–CaO composite catalysts in environmental remediation processes, particularly in treating textile industry effluents.

Synthesis of Mg-doped hydroxyapatite for enhanced photocatalytic degradation of Congo red dye: a crystallographic characterization

Synthesis of Mg-doped hydroxyapatite for enhanced photocatalytic degradation of Congo red dye: a crystallographic characterization

Photocatalytic degradation of methylene blue dye by ZnO nanoparticle thin films, using Sol–gel technique and UV laser irradiation

The focus of the current work is the study of the effect of the photo-catalytic activity of ZnO nanoparticles. The photocatalytic destruction of methylene blue dye, a common water contaminant, was used to assess the photocatalytic efficiency of the ZnO nanoparticles from its aqueous solution by using ZnO nanoparticles thin film under UV light and laser irradiation. Sol–gel methods prepared ZnO nanoparticle thin films. X-ray diffraction and a field-emitted scanning electron microscope were utilized to examine the structure of the produced ZnO nanoparticles. An extended characterization by laser-based fluorescence and UV–visible spectroscopic techniques. The effects of operational parameters such as photo-catalyst load and contact time on photocatalytic degradation of methylene blue were investigated. The recent study’s findings showed that irradiation with a UV laser increases with power density 25 µW/cm2, the photo-catalytic rate. The UV spectra show decay for the band at 664nm decreased and the concentration of M.B. in monomer form decayed to 26% of the original concentration in 24 h, while the band at 612 which is related to the dimer M.B. molecules was not affected. The laser irradiation did the same for monomer M.B. molecules in only 3 h, while the dimer decreased to 28% of its original concentration. The reaction mechanism has been discussed by molecular modelling. Quantum mechanical calculations at B3LYP/6-311g(d,p) level indicated that methylene blue changed from dimers to monomers in the existence of ZnO. The current results present a method for degrading M.B. not only in wastewater but also in the industrial waste scale.

Efficient and rapid sunlight-driven photocatalytic degradation of methylene blue dye using multiferroic BiFeO3 nanoparticles

Efficient and rapid sunlight-driven photocatalytic degradation of methylene blue dye using multiferroic BiFeO3 nanoparticles

Phase-selective fabrication of Cu-based films by magnetic field-assisted sparking process for improved photocatalytic dye degradation and CO2 reduction

Copper-based films (Cu2(OH)3NO3, Cu2O, and CuO) were successfully synthesized using a sparking process under an external magnetic field, without requiring an annealing process. We thoroughly investigate the impact of magnetic field orientation on the structural, morphological, and optical properties of the films, along with their performance in photocatalytic degradation of methylene blue (MB) and carbon dioxide (CO2) reduction. Field-emission scanning electron microscopy (FE-SEM) images reveal that the CuEB(S) sample displays secondary particles forming spherical, dense clusters, whereas the CuEB(N) sample exhibits larger, loosely packed clusters. In contrast, the cluster-like structures disperse in the CuEB(P) sample, resulting in a smoother film surface aligned with the parallel magnetic flux direction. Upon close observation, rice-shaped particles of varying sizes (26.3–60.3 nm) were found stacked together. This study presents a facile method to selectively fabricate films comprising single-phase Cu2(OH)3NO3, a CuO/Cu2O composite, or a combination of all phases by manipulating the external magnetic field orientation during the sparking process. All synthesized materials exhibit photocatalytic activity, with the heterojunction composed of CuO, Cu2O, and Cu2(OH)3NO3 demonstrating superior performance. This heterostructure achieved up to a 180 % enhancement in MB degradation and approximately doubled the CO2-to-CO conversion rate to 16.09 μmol g–¹ h–¹ compared to the sample prepared without a magnetic field.

Photocatalytic degradation of organic dyes under sunlight using a mononuclear Zn complex-embedded-functionalized porous material.

In this study, mesoporous materials (MCM-41 and MCM-48) were synthesized and functionalized with an acid group through a post-synthetic modification method. A mononuclear Zn complex [Zn(dmp)Cl2] (dmp = neocuprine) was also prepared and incorporated into a functionalized mesoporous material. Extensive characterization of the material married was carried out using techniques such as X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), and Fourier-transform infrared spectroscopy (FT-IR) to evaluate the characteristics of modified materials. The characterization results revealed that the post-synthetic modification did not alter the phase purity, crystallinity, or morphology of the mesoporous materials while confirming the successful grafting of the desired sulphonic acid functionality and Zn complex. The Zn complex-grafted-functionalized mesoporous materials were then assessed for their photo-degradation using methylene blue (MB) and rhodamine B (RB). The results demonstrated exceptional photo-degradation efficiency of the modified materials under sunlight. Within 15min, 10mg/ml of dye concentration, and adsorbent dosage 0.15mg/ml and 0.1mg/ml, degradation efficiencies of 99% and 92%, were achieved for MB using M-48-S-Zn1 and M-41-S-Zn1, respectively. Similarly, 91% and 78% degradation rates were achieved within 30min for RB using the same materials. The modified mesoporous materials exhibited a remarkable degradation performance even in challenging environments, including highly acidic, basic, and salt-concentrated conditions. This highlights the versatility and robustness of the modified materials in different environmental scenarios.

Photocatalytic degradation of organic dyes using titania modified with adsorbent nanolayers

Photocatalytic degradation of organic dyes using titania modified with adsorbent nanolayers

Exploration of Pristine ZnO and Cobalt Doped ZnO for the Solar Photocatalytic Degradation of Methylene Blue Dye

The ZnO and Co-doped ZnO were prepared by eco-friendly and modest route, including thermal disintegration of zinc oxalate (ZnOx) and cobalt-zinc oxalate (CoZnOx) powders, respectively, from a mechano-chemical method. The process of conversion of metal/s oxalate dihydrate to the pristine ZnO and cobalt-doped ZnO was studied with TG-DTG and FTIR spectroscopy. ZnO and Co-doped ZnO crystallites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy dispersive X-ray (EDX), UV–visible and photoluminescence (PL) spectroscopies. Hexagonal Wurtzite crystallite structures of the aforementioned materials were illustrated from XRD data. The surface morphological investigation was done with SEM. EDX study confirms the elemental purity of materials. Chemical bonding information was obtained from FTIR spectra. Optical properties were studied from UV-visible and photoluminescence spectroscopy. Exploration of pristine ZnO and cobalt-doped ZnO for the solar photocatalytic degradation (PCD) of methylene blue dye has been done in a batch photoreactor. The various related parameters such as photocatalyst amount, initial concentration of dye and pH were also examined for maximum degradation efficiency for mentioned dye.

Green synthesis of N-doped-carbon dots/ZnO for enhanced photocatalytic degradation of methylene blue dye: optimization of reaction parameters.

In this research work, nitrogen-doped carbon dots (N-CDs) adorned zinc oxide nanoparticles (N-CDs/ZnO) were successfully synthesized by a simple and cost-effective solution dispersion method and later on used as photocatalyst for decontamination of aqueous methylene blue (MB) dye on irradiation of UV light (300 W, 320-400nm) at room temperature. Both the N-CDs and ZnO were prepared through green technique utilizing non-toxic, inexpensive and eco-friendly precursors, namely Foeniculum vulgare and Psidium guajava leaf extract, respectively. All the synthesized samples exhibited crystalline nature with average diameter of particle 4.42nm, 12.38nm and 14.11nm corresponding to N-CDs, ZnO and N-CDs/ZnO, respectively. Further, band gap energy value (Eg) of 3.43, 2.76 and 2.49eV for N-CDs, ZnO and N-CDs/ZnO, respectively, were obtained by using Tauc's plot. The photocatalytic capability of the sample N-CDs/ZnO was compared with bare ZnO nanoparticles, utilizing identical experimental conditions. The results demonstrated that the composite exhibited notably higher photocatalytic degradation efficiency than bare ZnO nanoparticles up to 15.54%. Lower band gap value of N-CDs/ZnO was the major factor for exhibiting this behaviour, decreasing the recombination rate and thus enhancing the efficiency. Furthermore, N-CDs/ZnO exhibited 98.17% MB degradation under optimized conditions (0.03g, 5ppm, pH 10). The resultant N-CDs/ZnO exhibited good stability and decontamination efficiency up to five cycles with efficiency loss of only 7.89%. Along with, trapping experiments was conducted to analyze the role of active species involved for deep understanding of mechanism. The order of efficiency of active constituents was observed to be: •O2- > h+ > •OH. The study analyzed the non-toxic nature of treated water, revealing normal plant growth, suggesting its potential use in irrigation of parks and roadside areas. Overall, present research work obeys the green chemistry principles with the fabrication of highly efficient, eco-friendly, cost-effective photocatalyst N-CDs/ZnO by utilizing the green precursors for the whole research work.

Annealing effects on bio-fabricated nickel oxide nanoparticles for environmental remediation: Photocatalytic dye degradation and antimicrobial activity

Annealing effects on bio-fabricated nickel oxide nanoparticles for environmental remediation: Photocatalytic dye degradation and antimicrobial activity

Promising transition metal molybdate (TMM) single phase microstructures for asymmetric supercapacitor and photocatalytic applications

The increasing impact of worldwide energy challenges has sparked significant interest in developing multifunctional nanomaterials for energy and environmental applications. Among semiconductor photocatalysts, stable mixed metal molybdate materials have garnered much interest regarding energy storage and photocatalytic dye degradation. In this context, we have synthesized three different single-phase metal molybdates (NiMoO4, MnMoO4, and Fe2(MoO4)3) using the gel matrix method. XRD and Raman were executed to confirm phase formation of the acquired materials. Difference in surface morphology of synthesized transition metal molybdate powders was examined using SEM analysis. The energy-storing properties of synthesized transition metal molybdate powders were analyzed and compared using three and two electrode method. At a 1 Ag-1 current density, the as-synthesized NiMoO4, MnMoO4, and Fe2(MoO4)3 nanostructures exhibit specific capacitances of about 424.6, 325.5 and 157.8 Fg-1, respectively. Furthermore, the fabricated ASC device with NiMoO4 shows 41.6 Whkg-1 and 750 Wkg-1 as maximum energy and power density at 1 Ag-1, respectively. Meanwhile, photocatalytic methylene blue degradation was carried out using the as-synthesized materials as photocatalysts. The Fe2(MoO4)3 effectively decolourizes the dye with a maximum efficiency of 82.7 %, when compared to other two metal molybdate powders. Thus, the results show that the synthesized metal molybdates such as NiMoO4, and Fe2(MoO4)3 can act as potent electrode materials and efficient photocatalysts for energy storage and dye degradation applications when compared to MnMoO4.

One-step fabrication of S-scheme ZnO/g-C3N4 composites for enhanced environmental photocatalysis

This study focuses on synthesizing zinc oxide/graphitic carbon nitride (ZnO/g-C3N4) nanocomposites for efficiently degrading methylene blue (MB) dye via photocatalysis. Egg white was used as a surfactant agent in the synthesis process. The nanocatalysts were characterized using several techniques such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray analysis (EDS), Fourier-transform infrared (FTIR) spectroscopy, Brunauer-Emmett-Teller (BET) tests, UV-Vis spectroscopy, and photoluminescence (PL) spectroscopy. These ZnO/g-C3N4 nanocatalysts were then analyzed for their photocatalytic degradation of MB dye under direct sunlight. The results showed that the ZnCN2 sample achieved the highest efficiency, degrading 92% of MB within 60minutes. A pseudo-first-order kinetics was also confirmed for the photodegradation reaction. Radical scavenger studies revealed that superoxide and hydroxyl species were primarily responsible for the degradation of MB, and possible S-scheme photocatalytic mechanisms were proposed. Additionally, the ZnO/g-C3N4 composite exhibited excellent reusability and chemical stability, maintaining an unchanged degradation efficiency of MB after five cycles.

A novel RuO₂@ZnO-Alginate-Halloysite composite for the effective degradation of Eosin Yellow dye and Ciprofloxacin drug

This research explores the synthesis and application of a novel RuO₂@ZnO-Alginate-Halloysite composite to effectively mitigate Eosin Yellow (EY) and Ciprofloxacin (CIP). The composite exhibited a predominant zinc oxide (ZnO) phase with added ruthenium oxide (RuO₂), alginate, and halloysite components, confirmed through X-ray diffractogram (XRD), Raman, and Fourier Transform Infrared Spectroscopy (FTIR). The addition of RuO₂ did not alter the crystal structure significantly. Still, it impacted the optical properties, with the band gap energies ranging from 3.281 to 3.252 eV, indicating a redshift associated with increased RuO₂ concentration. The composites were tested for EY and CIP photocatalytic degradation under UV light. The composites containing 2 and 3% of RuO2 presented impressive photocatalytic performance, achieving up to 82.53% degradation of CIP and 68.68% of EY under UV irradiation respectively, highlighting its potential as a robust solution for environmental remediation. The study employed a series of scavenger tests to identify the primary reactive species involved in the photocatalytic degradation of ciprofloxacin drug and eosin yellow dye. The introduction of benzoquinone led to a significant decrease in photocatalytic activity, indicating that superoxide (•O₂⁻) and hydroxyl radicals (•OH) are the dominant species in the photocatalytic degradation of CIP and EY, respectively. The synergistic effects of these reactive species contribute significantly to the photocatalytic performance of the composite material. Finally, the composites showed good recyclability, maintaining substantial degradation performance over multiple cycles. The significance of this study is underscored by the urgent need to find effective methods for removing hazardous compounds from wastewater, a growing concern due to their harmful impact on aquatic ecosystems and human health.

Zinc/lead bimetallic sulfides as hybrid material for high-performance aqueous asymmetric supercapacitor and photocatalytic degradation of organic dye

Zinc/lead bimetallic sulfides as hybrid material for high-performance aqueous asymmetric supercapacitor and photocatalytic degradation of organic dye