Dye Bleaching Research Articles

Carbon-Based Materials in Combined Adsorption/Ozonation for Indigo Dye Decolorization in Constrain Contact Time.

This study presents a comprehensive evaluation of catalytic ozonation as an effective strategy for indigo dye bleaching, particularly examining the performance of four carbon-based catalysts, activated carbon (AC), multi-walled carbon nanotubes (MWCNT), graphitic carbon nitride (g-C3N4), and thermally etched nanosheets (C3N4-TE). The study investigates the efficiency of catalytic ozonation in degrading Potassium indigotrisulfonate (ITS) dye within the constraints of short contact times, aiming to simulate real-world industrial wastewater treatment conditions. The results reveal that all catalysts demonstrated remarkable decolorization efficiency, with over 99% of indigo dye removed within just 120 s of mixing time. Besides, the study delves into the mechanisms underlying catalytic ozonation reactions, elucidating the intricate interactions between the catalysts, ozone, and indigo dye molecules with the processes being influenced by factors such as PZC, pKa, and pH. Furthermore, experiments were conducted to analyze the adsorption characteristics of indigo dye on the surfaces of the materials and its impact on the catalytic ozonation process. MWCNT demonstrated the highest adsorption efficiency, effectively removing 43.4% of the indigo dye color over 60 s. Although the efficiency achieved with C3N4-TE was 21.4%, which is approximately half of that achieved with MWCNT and less than half of that with AC, it is noteworthy given the significantly lower surface area of C3N4-TE.

Freezing-enhanced degradation of azo dyes in the chloride-peroxymonosulfate system

In this study, we investigated the freezing-induced acceleration of dye bleaching by chloride-activated peroxymonosulfate (PMS). It has been observed that the oxidation of chloride by PMS generates a free chlorine species, such as hypochlorous acid (HOCl), under mild acidic and circumneutral pH condition. This process is the major reason for the enhanced oxidation capacity for electron-rich organic compounds (e.g., phenol) in the chloride-PMS system. However, we demonstrated that the chloride-PMS system clearly reduced the total organic carbon concentration (TOC), whereas the HOCl system did not lead to decrease in TOC. Overall, the chemical reaction is negligible in an aqueous condition if the concentrations of reagents are low, and freezing the solution accelerates the degradation of dye pollutants remarkably. Most notably, the pseudo-first order kinetic rate constant for acid orange 7 (AO7) degradation is approximately 0.252 h−1 with 0.5 mM PMS, 1 mM NaCl, initial pH 3, and a freezing temperature of −20 °C. AO7 degradation is not observed when the solution is not frozen. According to a confocal Raman-microscope analysis and an experiment that used an extremely high dose of reactants, the freeze concentration effect is the main reason for the acceleration phenomenon. Because the freezing phenomenon is spontaneous at high latitudes and at mid-latitudes in winter, and the chloride is ubiquitous elsewhere, the frozen chloride-PMS system has potential as a method for energy-free and eco-friendly technology for the degradation of organic pollutants in cold environments.

Significantly Enhanced Self-Cleaning Capability in Anatase TiO2 for the Bleaching of Organic Dyes and Glazes

In this study, the Mg2+-doped anatase TiO2 phase was synthesized via the solvothermal method by changing the ratio of deionized water and absolute ethanol Vwater/Vethanol). This enhances the bleaching efficiency under visible light. The crystal structure, morphology, and photocatalytic properties of Mg-doped TiO2 were characterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, N2 adsorption-desorption, UV-Vis spectroscopy analysis, etc. Results showed that the photocatalytic activity of the Mg2+-doped TiO2 sample was effectively improved, and the morphology, specific surface area, and porosity of TiO2 could be controlled by Vwater/Vethanol. Compared with the Mg-undoped TiO2 sample, Mg-doped TiO2 samples have higher photocatalytic properties due to pure anatase phase formation. The Mg-doped TiO2 sample was synthesized at Vwater/Vethanol of 12.5:2.5, which has the highest bleaching rate of 99.5% for the rhodamine B dye during 80 min under visible light. Adding Mg2+-doped TiO2 into the phase-separated glaze is an essential factor for enhancing the self-cleaning capability. The glaze samples fired at 1180 °C achieved a water contact angle of 5.623° at room temperature and had high stain resistance (the blot floats as a whole after meeting the water).

Effect of cation insertion on the stability of gliding arc plasma-precipitated mesoporous MnO2 dye bleaching catalysts

Effect of cation insertion on the stability of gliding arc plasma-precipitated mesoporous MnO2 dye bleaching catalysts

Development of a new CoS-Supported ZnAl2O4 catalyst for the visible photodegradation of a basic textile dye from water

The material is proven competitive for the solar treatment of wastewater from the textile industry -an essential source of water pollution worldwide. The system was prepared following a two-step hydrothermal method, showing photon absorption properties across the solar spectrum's UV and visible light regions. The main responsible species driving the photocatalytic process are proposed based on degradation experiments using appropriate scavengers. Further studies include consideration of operational parameters and cycling experiments to evaluate the stability of the catalyst. The results showed complete degradation (100%) based on dye bleaching and >90% mineralization of the dye based on total organic carbon analysis using dye concentrations of 20 ppm and catalyst loading of 1 g/l. Our findings point to sulfide-supported spinel materials as promising candidates for advanced solar oxidation technologies for wastewater treatment.

Photocatalytic Bleaching of Fast Green in Presence of Zinc Oxide as Photocatalyst

Abstract: The photocatalytic bleaching of Fast Green on zinc oxide powder has been carried out in presence of light. The photocatalytic bleaching of dye was observed spectrophotometrically. The effect of variation of different parameters like concentration of Fast Green, pH, amount of zinc oxide, and light intensity on the rate of photocatalytic bleaching was observed. A tentative mechanism for the photocatalytic bleaching of Fast Green has been proposed.

TiO2-Embedded Biocompatible Hydrogel Production Assisted with Alginate and Polyoxometalate Polyelectrolytes for Photocatalytic Application

The hybrid hydrogel materials meet important social challenges, including the photocatalytic purification of water and bio-medical applications. Here, we demonstrate two scenarios of polyacrylamide-TiO2 (PAAm@TiO2) composite hydrogel design using calcium alginate (Alg-Ca) or Keplerate-type polyoxometalates (POMs) {Mo132} tuning the polymer network structure. Calcium alginate molding allowed us to produce polyacrylamide-based beads with an interpenetrating network filled with TiO2 nanoparticles Alg-Ca@PAAm@TiO2, demonstrating the photocatalytic activity towards the methyl orange dye bleaching. Contrastingly, in the presence of the POM, the biocompatible PAAm@TiO2@Mo132 composite hydrogel was produced through the photo-polymerization approach (under 365 nm UV light) using vitamin B2 as initiator. For both types of the synthesized hydrogels, the thermodynamic compatibility, swelling and photocatalytic behavior were studied. The influence of the hydrogel composition on its structure and the mesh size of its network were evaluated using the Flory–Rehner equation. The proposed synthetic strategies for the composite hydrogel production can be easily scaled up to the industrial manufacturing of the photocatalytic hydrogel beads suitable for the water treatment purposes or the biocompatible hydrogel patch for medical application.

C-TiO2+Ni and ZnO+Ni Magnetic Photocatalyst Powder Synthesis by Reactive Magnetron Sputtering Technique and Their Application for Bacteria Inactivation

In the current study, a bi-layered magnetic photocatalyst powder consisting of a Ni layer on one side and carbon-doped TiO2 or ZnO photocatalyst layers on the other side was synthesized by magnetron sputtering technique. SEM, XRD, and XPS analysis of powders revealed that the photocatalytic TiO2 layer had a mixed anatase-rutile structure, was doped by carbon to approximately 3 at. % and had a fraction of Ti(III) oxide. Meanwhile, the ZnO layer was crystalized in a wurtzite structure and had a considerable number of intrinsic defects, which are useful for visible light photocatalysis. The activity of magnetic photocatalyst powder was tested by photocatalytic bleaching of dyes, as well as performing photocatalytic inactivation of Salmonella bacteria under UV and visible light irradiation. It was observed, that C-TiO2+Ni magnetic photocatalyst had relatively high and stable activity under both light sources (for five consecutive cycles dye degradation reached approximately 95%), but ZnO+Ni was generally lacking in activity and stability (over five cycles under UV and visible light, dye degradation fell from approximately 60% to 55% and from 90% to 70%, respectively). Photocatalytic treatment of bacteria also provided mixed results. On one hand, in all tests bacteria were not inactivated completely. However, on the other hand, their susceptibility to antibiotics increased significantly.

Synthesis and Characterization of Late Transition Metal Complexes of Mono-Acetate Pendant Armed Ethylene Cross-Bridged Tetraazamacrocycles with Promise as Oxidation Catalysts for Dye Bleaching

Ethylene cross-bridged tetraazamacrocycles are known to produce kinetically stable transition metal complexes that can act as robust oxidation catalysts under harsh aqueous conditions. We have synthesized ligand analogs with single acetate pendant arms that act as pentadentate ligands to Mn, Fe, Co, Ni, Cu, and Zn. These complexes have been synthesized and characterized, including the structural characterization of four Co and Cu complexes. Cyclic voltammetry demonstrates that multiple oxidation states are stabilized by these rigid, bicyclic ligands. Yet, redox potentials of the metal complexes are modified compared to the "parent" ligands due to the pendant acetate arm. Similarly, gains in kinetic stability under harsh acidic conditions, compared to parent complexes without the pendant acetate arm, were demonstrated by a half-life seven times longer for the cyclam copper complex. Due to the reversible, high oxidation states available for the Mn and Fe complexes, the Mn and Fe complexes were examined as catalysts for the bleaching of three commonly used pollutant model dyes (methylene blue, methyl orange, and Rhodamine B) in water with hydrogen peroxide as oxidant. The efficient bleaching of these dyes was observed.

Definite Identifiers of Silver Dye Bleach Prints

Among diverse contemporary colour prints, silver dye bleach prints and chromogenic prints are difficult to differentiate. They share similar visual characteristics and can use identical supports and surface finishes. However, their image-forming dyes differ, resulting in disparate conservation and restoration needs. This study aimed to determine practical measures for unambiguously differentiating between these two print types. Identifying characteristics—referred to here as ‘identifiers’—were collected from popular conservation sources and a mixed-method questionnaire survey. The accuracy and feasibility of these identifiers were evaluated against known prints sets. Examinations made use of water droplets, various light sources, digital 3D microscopy, and spectrophotometry. Results dichotomised these identifiers into ‘definite’ or ‘indefinite’ with ‘definite identifiers’ being able to discriminate independently. Only five out of 23 entries were termed definite identifiers. Azo dyes—image dyes of silver dye bleach prints—were established as the only constant definite identifiers of this print type. These findings were integrated into a flowchart to guide differentiation with the main recommendation being to deviate from indefinite identifiers to save time and effort. Parts of this work have been submitted in partial fulfilment of the requirements for a Master of Science degree at the University of Amsterdam in 2020.

Characterization of Laccase from the Fungi Fusarium Isolated from Potato Peels Using Carbon and Nitrogen Sources

Laccases (E.C. 1.10.3.2 benzenediol: oxygen oxidoreductase) are an interesting group of N glycosylated multicopper blue oxidase enzymes. They are widely found in fungi, bacteria plants, insects, and lichen. They catalyze the oxidation of various phenolic and non-phenolic compounds, with the concomitant reduction of molecular oxygen to water. Laccase has various applications in industries such as textile dye bleaching, paper, and pulp bleaching, food processing, bioremediation, biodegradation, wood processing, and pharmaceuticals. However, the high cost of production has been a major hindrance to its commercial usage. This study was carried out to investigate the extraction, purification, and characterization of laccase from fungi isolated from potato peels using three different substrates. Extraction was carried out using submerged fermentation, with glucose, lactose, and maltose as the carbon sources and varying nitrogen sources; yeast and ammonium chloride (NH4Cl) Laccase was also characterized by assessing parameters such as pH, temperature, and protein concentration. Enzyme activity for maltose (yeast), glucose (yeast), glucose (NH4Cl) and lactose (NH4Cl) increased from 25oC -45 oC with optimum pH of 6,6,8 and 5 respectively while activity for maltose (NH4Cl) and lactose(yeast) increased from 25oC-65oC with optimum pH at 5 and 8 respectively. This study suggests that increased laccase production from potato peels can be achieved by using maltose, glucose and lactose as carbon sources with NH4Cl as nitrogen source.

Analysis of laccase-like enzymes secreted by fungi isolated from a cave in northern Spain.

Laccases belong to a family of multicopper enzymes able to oxidize a broad spectrum of organic compounds. Despite the well‐known property of laccases to carry out bleaching and degradation of industrial dyes and polyphenolic compounds, their industrial use is often limited by the high cost, low efficiency, or instability of these enzymes. To look for new microorganisms which produce laccases that are potentially suitable for industrial applications, we have isolated several fungal strains from a cave in northern Spain. Their phenotypic analysis on agar plates supplemented with ABTS (2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid)) disclosed two laccase‐positive strains. Further genotyping revealed that they belonged to the Gliomastix murorum and Conidiobolus thromboides species. The secretion of G. murorum and C. thromboides laccase‐like enzymes was then confirmed by zymography. Further identification of these polypeptides by mass‐spectroscopy revealed the nature of the laccases and made it possible to predict their functional domains and other features. In addition, plate assays revealed that the laccases secreted by both G. murorum and C. thromboides were capable of degrading industrial dyes (Congo Red, Indigo, and Eriochrome Black T). Homology modeling and substrate docking predicted the putative structure of the currently uncrystallized G. murorum enzyme as well as its amino acid residues potentially involved in interactions with these dyes. In summary, new biochemical and structural insights into decolorization mediated by G. murorum laccase as well as identification of laccase‐like oxidase in C. thromboides point to a promising future for these enzymes in biotechnology.

Selective oxidation and direct decolorization of cationic dyes by persulfate without activation

The aim of this work was to investigate the selective oxidation and direct decolorization of selected organic dyes (Methylene Blue (MB), Rhodamine B (RhB) and Orange II (OrgII)) by persulfate (PDS) without activation. Results show that the decolorization rate of MB was up to 58.0% within 10 minutes, while those of RhB and OrgII were only about 29.6% and 3.0% after 80 minutes, respectively. In comparison with the negligible impacts of pH from 2.0 to 9.0 on MB and OrgII decolorization, RhB decolorization rate obviously varied with the pH changes, and acid pH condition was beneficial for RhB decolorization. Quenching tests implied that the decolorization of dyes by PDS without activation was a nonradical oxidation process rather than sulfate radical oxidation. A plausible mechanism is that the decolorization process is attributed to the charged states of the dyes at different pH conditions, and thus direct electron transfer from dyes to PDS may occur, which is responsible for the bleaching of dyes. This study points out the potential bleaching capability of PDS without activation on cationic dyes, which may have important implications for selective oxidation treatment of dye wastewater.

A novel peroxidase from runner bean (Phaseolus coccineus L.): Enhanced affinity purification, characterization, and dye decolorization activity.

In this study, a novel runner bean peroxidase (RBP) was purified and characterized. Affinity-based purification was performed with newly synthesized disubstituted 4-aminobenzohydrazides. In the purification results, 253-fold was achievedwith a yield of 56.2%. Furthermore, molecular weight and enzyme purity were checked with the SDS-PAGE and observed a single band at 31.2kDa. Optimum conditions were determined as temperature=50°C, ionic strength=0.2M, and pH 7.0. Enzyme exhibited 31.2% of residual activity in the presence of 20% DMSO. Additionally, the redox-mediated decolorization effect of the enzyme was examined for Reactive Blue 19 and Acid Blue 25 dyes. As a result of 1-hr incubation, the enzyme removal activity of Reactive Blue 19 and Acid Blue 25 dyes was calculated as 47% and 57%, respectively. PRACTICAL APPLICATIONS: Peroxidases (PODs) ability to catalyze various redox reactions for many substrates makes them significant enzymes in industrial sectors. In our current report, a single-step strategy was developed and followed as an alternative to multi-step methods commonly used for the purification of PODs. During this process, high yield was achieved and the separation time was shortened. Also, the purification of RBP that can potentially supplant PODs used in the industrial applications was carried out for the first time. In addition, substrate specificity, catalytic behavior in water-miscible organic solvents, and dye bleaching activity of this enzyme have been determined to evaluate the utilization capacity in various processes.

Nanocomposite Fiber Based on Natural Material for Water Disinfection under Visible Light Irradiation.

In the last decade, pathogenic bacteria and organic micropollutants have become a major issue in the water purification process. Heterogeneous photocatalysis is a low-cost and an ecofriendly process, which provides a sustainable solution for water treatment and its utilization in rural areas. In this context, we studied the generation and the surface engineering of polyacrylonitrile (PAN)/goethite composite nanofibers for photocatalytic water remediation under visible-light illumination. The photocatalytic activity was evaluated for dye (methylene blue) degradation and bacteria inactivation, as contaminant models, of the composite nanofibers. The PAN/goethite nanofibers were elaborated by an electrospinning technique, and the morphology and the composition, before and after spin coating, were investigated by Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray (EDX). The results showed partially intercalated structures of the PAN/goethite Composite-nano-fiber (CNF) were identified by SEM and EDX analysis. The composite nanofibers exhibited high photoefficiency upon dye bleaching (only 10% left after 5 h of illumination) and bacterial deactivation Escherichia coli and Clostridium perfringens (4.4- and 3.5-fold, respectively, in less than 5 h). The steadiness and pliancy of the generated nanofibers provide a promising application in the continuous flow system.

Catalytical properties of the polyanilylin-MnO2 composite in organic dye decoloration reactions

This work is devoted to the study of the regularities of the oxidation reactions of the dye (methyl orange) using hydrogen peroxide in the presence of a heterogeneous catalyst (PAn–MnO 2 composite), which we synthesized to increase the speed of the specified chemical reaction. When added to the reaction mixture containing H 2 O 2 and organic dye, the catalyst, which is a composite of the conjugated polymer and the transition metal oxide, can generate hydroxyl radicals, which are powerful oxidizing agents. This allows for higher rates of the dye bleaching reaction to be achieved compared to those occurring when using H 2 O 2 without a catalyst. The polyaniline–MnO 2 composite was synthesized by the method of oxidative polycondensation of aniline under the action of MnO 2 , which was dispersed in 100 ml of 1.15 mol/l aqueous sulfuric acid, the reaction was carried out at a ratio of MnO 2 : An = 1:1. In the infrared spectrum of the polyaniline–MnO 2 composite, a wide range of absorption peaks between 500 and 800 cm -1 , which are related to the vibrations of Mn–O atoms in MnO 6 octahedra, are observed; the peaks at 1 300 and 1 243 cm -1 belong to the C–N valence vibrations for the benzoid form (secondary aromatic amine), and the peak at 1 142–1 153 cm –1 belongs to the quinoid form of the doped PAn, the peak at 800 cm -1 refers to the vibrations of atoms in the C–C and C–H groups of the benzoid form. An intermolecular interaction appears to occur between the polyaniline quinoid and benzoid groups and Mn–O, which are part of the composite. We have studied the catalytic properties of the composite (PAn–MnO 2 ) and the original manganese oxide in the decolorization reactions of the MO dye under the action of H 2 O 2 . It has been shown that in the presence of manganese oxide, the oxidation of MO occurs faster than during the action of the composite (PAN – MnO2). The catalytic reaction constant in the first case has a relatively higher numerical value (1.85 × 10 -4 s -1 and 0.23 × 10 -4 s -1 , respectively). Keywords: polyaniline, composite, MnO 2 , catalysis, methyl orange

Degradation Protection of Color Dyes Encapsulated by Graphene Barrier Films

The decolorization of paintings, photographs, and artworks is a common phenomenon related to the oxidative degradation of color dyes reacting with oxygen or water molecules, which also causes a critical problem in organic light-emitting diodes (OLEDs). It is expected that the gas-impermeable property of graphene and h-BN can be utilized to protect the color dyes from degradation. However, the transfer method has been limited to a polymer with high glass transition temperature (Tg) or a glass substrate due to hot or wet transfer conditions. Here, we report the dry transfer coating of the graphene barrier films on flexible substrates at room temperature using a roll-to-roll process to prevent the bleaching of color dyes, which can be widely used to protect various colorization and light-emitting materials for sustainable printing and display technologies in the future.

A Horizontal Sequential Cutting Method to Estimate the Effectiveness of Dentin Disinfection by Using Confocal Laser Scanning Microscopy

IntroductionThis study aimed to develop a technique to create sequential slices, allowing the fluorescent visualization of bacterial viability in all parts of an infected dentin. MethodsCylindrical dentin blocks were prepared from freshly extracted human teeth with a single-rooted canal. Each block was immersed in 5% sodium hypochlorite (NaOCl) and 17% EDTA for 5 minutes before being infected with Enterococcus faecalis. The bacteria were allowed to develop inside dentin specimens for 28 days under anaerobic conditions. The specimens were exposed in 2% NaOCl for either 2 minutes or 20 minutes at 20°C, 37°C, and 45°C, respectively. After staining with calcein AM (Thermo Fisher Scientific, Waltham, MA) and propidium iodide, the samples were cryoembedded, mounted on an adhesive film, and sectioned at a thickness of 10 μm along the running of the dentinal tubules. Stacks of fluorescent images were collected in the z dimension using confocal laser scanning microscopy, and the maximum affected distance from a root canal was measured from the 3-dimensional reconstructed image. The reliability of this technique was verified by comparison with a dye bleaching test. ResultsHorizontal sequential sections preserving 3-dimensional bacterial distribution and their viabilities could be made without decalcification. The treatment time contributed to the penetration of NaOCl into dentinal tubules, whereas temperature did not significantly affect the penetration. The judgment by confocal laser scanning microscopic analysis was consistent with that of a dye bleaching test. ConclusionsThe horizontal sectioning method has the advantage of creating sequential sections, allowing information to be imaged at every portion.

Characterization of recombinant laccase from Trametes versicolor synthesized by Arxula adeninivorans and its application in the degradation of pharmaceuticals

Recent years have seen an increasing interest in laccase enzymes. Due to their ability of oxidizing various substrates, they are nowadays applied in multiple industrial fields including pulp delignification, textile dye bleaching, and bioremediation. In contrast to laccase production from native sources, with its generally low yield and high cost, heterologous laccase expression is far better suited to meet the growing industrial demands. TVLCC5 gene encoding Trametes versicolor laccase 5 was overexpressed in Arxula adeninivorans using the strong constitutive TEF1 promoter. Recombinant Tvlcc5 protein was purified by immobilized-metal ion affinity chromatography and biochemically characterized using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) as substrate for standard activity assays. The enzyme showed the highest activity at 50 °C between pH 4.5–5.5. The half-life of Tvlcc5 at 60 °C was around 20 min. The negative effect of chloride anions on enzyme activity was demonstrated. A fed-batch cultivation of Tvlcc5 producing strain A. adeninivorans G1212/YRC102-TEF1-TVLCC5-6H was performed and resulted in a laccase activity of 4986.3 U L−1. To improve the expression level of recombinant laccase in A. adeninivorans, cultivation conditions were optimized by single factor experiments. Recombinant Tvlcc5 proved to be a promising agent for degradation of pharmaceuticals that are an important source of environmental pollution. Concentration of diclofenac and sulfamethoxazole decreased to 46.8% and 51.1% respectively after 24 h incubation with Tvlcc5. When 1 mM redox mediator ABTS was added complete degradation was obtained within 1 h.

Comparison between catalytic activities of two zinc layered hydroxide salts in brilliant green organic dye bleaching

This paper reports the use of two layered hydroxide salts (LHS) (zinc hydroxide nitrate – ZHN – Zn5(OH)8(NO3)2·2H2O, and zinc hydroxide chloride – ZHC – Zn5(OH)8Cl2·H2O) as catalysts for brilliant green (BG) organic dye bleaching, using hydrogen peroxide as oxidant. The LHS were prepared by precipitation reaction between an aqueous solution of zinc salts and an aqueous ammonia solution. The solids were characterized by powder X-ray diffraction (XRD), electron paramagnetic resonance (EPR), ultraviolet-visible electronic spectroscopy (UV–Vis) and Fourier-transform infrared spectroscopy (FTIR). The catalytic activity of the solids was investigated at temperatures of 25, 35 and 45 °C, using different molar ratios of oxidant:dye:Zn2+ ions (present in the catalyst), in the absence and presence of ambient light. The kinetic aspect of the reaction was investigated considering that the reaction showed pseudo-first order behavior in relation to BG dye concentration. We propose a mechanism where superoxide radicals account for most of the bleaching taking place. The catalytic results obtained, along with the low cost and low toxicity of zinc compounds, establish ZHN and ZHC as novel catalysts for dye wastewater treatment, an area with constant demand for new methods and materials given its relationship with environmental equilibrium and human health.