Decomposition Of Dye Research Articles

Enhanced Piezo‐photocatalytic Performances of AgNbO3 Materials for Dye Decomposition Via Polarization Engineering

AbstractThe limitation to enhancing photocatalytic performance in photocatalysts lies in the rapid recombination of photo‐induced electrons and holes. Herein, AgNbO3 photocatalysts were synthesized by the hydrothermal method. The effects of hydrothermal temperature on the microstructure and photocatalytic/piezo‐photocatalytic performances of AgNbO3 have been systematically investigated. The AgNbO3 cubes synthesized at 180 °C for 24 h exhibited the best photocatalytic/piezo‐photocatalytic performances among all samples. The corona poling as an important method of polarization engineering is applied to promote further the separation and migration of charge carriers in AgNbO3. The polarized AgNbO3 synthesized at 170 °C exhibited outstanding piezo‐photocatalytic performance, and a degradation rate of 95 % for RhB within 90 min and a high apparent rate constant of 0.02978 min−1 were achieved. On the one hand, the alternating piezoelectric field caused by ultrasonic‐assisted illumination destroyed the shielding effect and enhanced the separation of electron‐hole pairs. On the other hand, polarization engineering induced by corona poling promoted the separation and migration of photo‐induced carriers, thereby realizing more efficient utilization of these charges during the photocatalytic decomposition process. This work presents a facile way to achieve superior piezo‐photocatalytic performances of AgNbO3‐based photocatalyst via polarization engineering.

Biocatalyst coupling with Mo-doped SnO2 nanoparticles for efficient photocatalytic dye degradation: An eco-friendly approach for environmental remediation

Specifically, biocatalyst coupled semiconductor photocatalysts have great potential towards the eco-friendly decomposition of toxic organic dyes that contaminate water bodies. This study reports the synthesis of vermiwash activated molybdenum doped tin oxide (Mo:SnO2) nanomaterial, for the photocatalytic degradation of a representative cationic dye - methylene blue (MB). The photocatalytic performance of the synthesized nanoparticles was evaluated using UV-visible (UV-vis) spectroscopy and the degrading efficiency of MB dye was quantified. The addition of vermiwash resulted in a marked improvement in the photocatalytic activity of Mo:SnO2 nanoparticles, with a degradation efficiency of 96% achieved after 75 min of irradiation. The nanoparticles were characterized using XRD, SEM-EDX, TEM, FTIR, XPS and UV-vis to confirm the crystal structure, morphology, functional groups, elemental analysis and bandgap energy by using Tauc’s plot. The study demonstrates the potential of vermiwash as a green and efficient bio co-catalyst for improving the photocatalytic activity of Mo:SnO2 nanoparticles regarding the degradation of textile effluents. Thus, this study paves a way for new eco-friendly approach for the synthesis of cost-effective, biocatalyst coupled semiconductor photocatalyst.

The Development and Synthesis of a CdZnS @Metal–Organic Framework ZIF-8 for the Highly Efficient Photocatalytic Degradation of Organic Dyes

The development of photocatalysts for organic degradation is a hot research topic. In this study, CdZnS was selected as the carrier, and ZIF-8 was combined with it to explore the photocatalytic performance of the composite. In addition, the compound material, CdZnS@ZIF-8, was used as a photocatalyst for the decomposition of methylene blue dye, and the performance of pure CdZnS and pure ZIF-8 was compared. The photocatalytic efficiency of CdZnS@ZIF-8 was significantly higher than that of the other two. In the experimental reaction, the amount of catalyst was 0.04 g, the pH value was 7, the initial concentration of methylene blue aqueous solution was 20 mg/L, and the degradation of methylene blue in 50 mL aqueous solution could reach 99.5% under visible light irradiation for 90 min, showing excellent photocatalytic efficiency in the visible light range. It demonstrated excellent photocatalytic function in the visible light region, and the electron transfer phenomenon at the interface occurred in the het-junction and the separation of the photo-generating electron–hole as an electron acceptor of ZIF-8 further promoted the photocatalytic effect.

A novel porous and highly efficient Fe-Ce-Co nanoparticles anchored in biochar derived from coconut husk for photo-Fenton degradation of binary mixtures of dyes

In this study, Fe-Ce-Co@BC, a biochar-based nanocatalystmaterial, was synthesized and used for the photocatalytic decomposition of hazardous dyes (Rhodamine B and Methylene Blue) in open exposure to the sun. The Fe-Ce-Co@BC photocatalyst was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray analysis (EDAX) and high-resolution transmission electron microscopy (HRTEM), in order to determine its structure, composition and morphology. For an accurate evaluation of the nanocatalyst sample's optical characteristics, UV–visible (UV–vis) spectrophotometry was used. The photocatalytic ability of the as-synthesized nanocatalyst was evaluated by analyzing dye degradation under visible light irradiation. Data from SEM, TEM, XRD, HRTEM, and XPS showed that the expected nano-catalyst had formed. From the nanocatalyst band-gap position, it implies a substantial decrease in the rate of electron-hole recombination and thereby improved charge separation. Thus, it turned out that the nanocatalyst's effective photocatalytic activity had resulted from the synergistic interactions between the various moieties. Under visible light irradiation for 35 and 25 min, the photocatalyst was observed to degrade the developing organic water pollutants RhB and MB by 94.24 ± 1.21% and 96.34 ± 1.42%, respectively. Pseudo-first order kinetics were used to guide the photodegradation, with specific reaction rates of 0.1117 and 0.1364 min−1, respectively. Investigations have also been done into how other factors, including contact duration, catalyst dosage, starting concentration, and water matrices, affect degrading performance. The current study achieves its goal of creating a nano-photocatalyst with excellent photostability and reusability that is effective in the visible area of the electromagnetic spectrum and can break down emergent, non-biodegradable organic components water pollutants.

Enhanced electrocatalytic degradation of acid orange 7 by using double perovskite La2CoxNi1-xMnO6/nickel foam as the electro-Fenton cathodes

Adequate generation of hydrogen peroxide and its subsequent activation into reactive oxygen species (ROS) play a crucial role in the catalytic efficiency of heterogeneous electro-Fenton for the degradation of contaminants. Herein, a series of La2NiMnO6 double perovskite with Co doping (La2CoxNi1-xMnO6) were prepared by a facile sol-gel technique and applied as catalysts in heterogeneous electro-Fenton system to removal acid orange 7 (AO7). Nickel foam was chosen as the supporting substrate for the catalyst owing to its excellent physical properties to accelerate the conversion of O2 to H2O2. La2Co0.5Ni0.5MnO6 achieved 90.22 % of AO7 decomposition rate at 120 min via the heterogeneous electro-Fenton system, which was a significant improvement over the catalytic efficiency of both only NF and La2NiMnO6 electrodes. Further studies have shown that the introduction of Co could heighten the efficient redox recycling of Ni2+/Ni3+ and Mn3+/Mn4+ on the electrode surface, synergically facilitating the conversion of H2O2 to OH. Meanwhile, the three redox pairs (Ni2+/Ni3+, Mn3+/Mn4+ and Co2+/Co3+) also stimulated the production of superoxide radicals (O2−), which was also not negligible in enhancing degradation. Finally, the possible pathway and mechanism of the degradation of AO7 were proposed. This work demonstrates that La2CoxNi1-xMnO6/NF has the potential to be a satisfactory electrode for decomposition of organic dyes in aqueous solution.

Evaluation of the Applicability of Modifying CdSe Thin Films by the Addition of Cobalt and Nickel to Enhance the Efficiency of Photocatalytic Decomposition of Organic Dyes

This article presents the results of an assessment of the use of CdSe, NiCdSe, and CoCdSe thin films as a basis for photocatalysts used for the decomposition of the organic dyes rhodamine B, cargo red, and indigo carmine. Interest in this area was determined by the need to solve a number of issues related to increasing the efficiency purifying aqueous media from the negative effects of organic dyes, which cannot be disposed of using traditional methods associated with adsorption or filtration. The use of the electrochemical synthesis method to obtain thin films of a given thickness showed that the addition of nickel or cobalt sulfates to the standard electrolyte solution used to obtain CdSe films results in the formation of CdSe films with a higher degree of structural ordering (the crystallinity degree was more than 50%), as well as a decline in the band gap. When analyzing data on the photocatalytic decomposition of organic dyes, it was found that a change in the structure of the films due to the introduction of nickel and cobalt leads, in the case of the decomposition of the rhodamine B dye, to a more efficient decomposition, and in the case of the cargo red and indigo carmine dyes, not only to their complete decomposition and mineralization, but also to a reduction in the time of photocatalytic reactions (decomposition growth rate). Moreover, an analysis of cyclic tests demonstrated that NiCdSe and CoCdSe films maintain 90% of their photocatalytic decomposition efficiency compared to that achieved during the first decomposition cycle, while CdSe degrades after three consecutive cycles and its efficiency reduces by more than 2.5–3 times.

Strongly piezocatalytic dye decomposition of sol-gel synthesized PZT film

Piezocatalysis technology emerges as a promising solution for environmental protection and wastewater pollution treatment. This study focuses on the synthesis of Pb(Zr0.50Ti0.50)O3 (PZT) ferroelectric thin films as piezocatalysts through a sol-gel method. The piezocatalytic performance of these PZT films under vibration is also evaluated through utilizing Rhodamine B(RhB) dye as a model pollutant. When vibrations are applied to the RhB solution for 3 h, the RhB dye decomposition ratio reaches 90.22 %. The influence of pH values, vibration power and dye concentration condition on the decomposition ratio of RhB dye wastewater during the piezocatalytic process. Furtherly, these inhibitor experiments indicate that these middlle active species in piezocatalysis of PZT film are mainly the ·O2− and ·OH radicals. The study demonstrates the tremendous potential of PZT film's piezoelectric effect in treating dye wastewater through harvesting mechanical vibration energy.

Photocatalytic decomposition of methylene blue and methyl orange dyes using pistachio biochar/CoFe2O4/Mn-Fe-LDH composite as H2O2 activator

Photocatalysis has gained a lot more notice due to its simplicity, cost-effectiveness, and efficiency, especially for dye degradation. In this study, a novel composite (PBC/CoFe2O4/Mn-Fe-LDH) including pistachio biochar (PBC), CoFe2O4 magnetic nanoparticles, and Mn-Fe-layered doubled hydroxide (LDH) was produced using a co-precipitation method. The composite was utilized to remove methylene blue (MB) and methyl orange (MO) dyes from aqueous solutions by the photodegradation method. The Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy-energy dispersive X-ray (SEM-EDX) analyses were used for characterization of the desired samples. The designed variables were pH (2-10), concentration of dye (10-30 mg.L−1), photocatalyst amount (0.2-1 g.L−1), H2O2 quantity (10-50 µL/100 mL), and time (10-50 min). The maximum degradation of MB and MO at optimal conditions (pH: 2 for MO and 10 for MB, dye concentration: 10 mg.L−1, catalyst mass: 1 g.L−1, time: 50 min, H2O2 value: 30 μL/100 mL) was obtained 99.10% and 99.89%, respectively. The scavenger effect investigation indicated that the species of OH• and O2•−, and h+ have the main function in the MB and MO degradation. The data were well explained by the pseudo-first-order kinetic model, and the constants for MB and MO dye elimination were established as 0.060 min−1 and 0.056 min−1, respectively. The PBC/CoFe2O4/Mn-Fe-LDH as a novel and promising composite could be useful for dye degradation in the photocatalytic reactor.

Effect of aliovalent substitution in the band structure engineered Ca2+-doped LaFeO3 nanoparticles for visible light-induced photocatalytic studies

Herein we demonstrate the influence of aliovalent (Ca2+) substitution in the single-phase orthorhombic La1-xCaxFeO3 (with x = 0.01, 0.03, 0.05, 0.07, 0.09) nanoparticles prepared by simple combustion method. The samples were systematically studied using XRD, SEM-EDS, and UV–Vis-DRS characterization techniques for their structural, microstructural-elemental, and optical (band structure) characteristics. Also, the catalytic attributes were evaluated through photocatalytic studies against indigo carmine in the presence of visible light. It was observed that La1-xCaxFeO3 nanoparticles crystallized in orthorhombic structure at its as-synthesized form. The SEM analysis showed that the spherical nanoparticles with high porosity and agglomerations were further reduced with increasing Ca2+ concentration. The inclusion of Ca2+ also demonstrated the change in the band structure, as the band gap of the material reduced from 2.24 eV to 1.75 eV while the Ca2+ content increased from 1 mol% to 9 mol%. Furthermore, elevating the Ca2+ levels in the La1-xCaxFeO3 resulted in enhanced photocatalytic decomposition of the indigo carmine dye, exhibiting a maximum efficacy of 96.5 % at neutral pH and a stabilization period of 120 min under visible light. The increase in photocatalysis is attributed to the formation of Fe4+ ions and oxygen vacancies induced by the aliovalent cation (Ca2+) replacement at the La3+ site in the LaFeO3 host matrix. The results suggest that the prepared LaFeO3 nanoparticles are potential nano-catalysts for photocatalytic activities against indigo carmine under visible light.

New Transition Metal Coordination Polymers Derived from 2-(3,5-Dicarboxyphenyl)-6-carboxybenzimidazole as Photocatalysts for Dye and Antibiotic Decomposition.

Coordination polymers (CPs) are an assorted class of coordination complexes that are gaining attention for the safe and sustainable removal of organic dyes from wastewater discharge by either adsorption or photocatalytic degradation. Herein, three different coordination polymers with compositions [Ni(HL)(H2O)2·1.9H2O] (1), [Mn3(HL)(L)(μ3-OH)(H2O)(phen)2·2H2O] (2), and [Cd(HL)4(H2O)]·H2O (3) (H3L = 2-(3,5-dicarboxyphenyl)-6-carboxybenzimidazole; phen = 1,10-phenanthroline) have been synthesized and characterized spectroscopically and by single crystal X-ray diffraction. Single crystal X-ray diffraction results indicated that 1 forms a 2D layer-like framework, while 2 exhibits a 3-connected net with the Schläfli symbol of (44.6), and 3 displays a 3D supramolecular network in which two adjacent 2D layers are held by π···π interactions. All three compounds have been used as photocatalysts to catalyze the photodegradation of antibiotic dinitrozole (DTZ) and rhodamine B (RhB). The photocatalytic results suggested that the Mn-based CP 2 exhibited better photodecomposition of DTZ (91.1%) and RhB (95.0%) than the other two CPs in the time span of 45 min. The observed photocatalytic mechanisms have been addressed using Hirshfeld surface analyses.

Rational construction of hollow ZnO@SnS2 core-shell nanorods: A way to boost catalytic removal of Cr (VI) ions, antibiotic and industrial dyes

Herein, the novel hollow ZnO@SnS2 core-shell nanorods with variable shell thickness have been synthesized by a chemical synthesis approach. The transmission electron microscopy (TEM) images signified the creation of a hollow core-shell nanostructure. The SnS2 layer coating on ZnO nanorods broadens visible light absorption and suppresses near-band edge emission of ZnO nanorods. Interestingly, the band gap (optical) of the developed ZnO nanorods decreased from 3.3 eV to 2.1 eV after the coating of SnS2 shell. Consequently, the coated hollow ZnO@SnS2 core-shell nanorods displayed a significant enhancement in catalytic activity for the decomposition of toxic industrial dyes, pharmaceutical pollutant tetracycline, and Cr(VI) ion in comparison to hollow ZnO NRs. The photon-induced charge carrier generation and separation were confirmed by the three-electrode electrochemical amperometric analysis and impedance analysis under illumination of simulated solar light (AM 1.5, One Sun). Moreover, an exceptionally higher photocurrent generation (∼10 times higher than ZnO nanorod). The improved ZnO@SnS2 core shell NRs catalytic activity was attributed to its core-shell structure, proper band structure, and effective charge carrier transfer across the core shell interface. This work offers new insights for the design and growth of visible light-active core shell nanorods for resolving environmental pollution and photocurrent generation.

Simple single reactor synthesis of nickel (II)-cobalt (II) ferrite composites with biochar and their photocatalytic properties

The paper proposes a simple one-stage synthesis of ferrite/biochar composites based on oxide compounds of NixCo1-xFe2O4 (х = 0, 0.5, and 1). The obtained materials were characterised using x-ray diffraction patterns, Fourier transform infrared (FTIR) spectrometry, electron microscopy, Scherrer and Williamson-Hall methods. The high photocatalytic activity of the synthesised materials in the process of methyl orange oxidative degradation at hydrogen peroxide presence has been established. It is noted that the highest catalytic activity is exhibited by the composite material based on cobalt (II) ferrite and sunflower biochar: in their presence, it is possible to achieve 100% removal of the dye after 120 and 90 min, respectively. A possible mechanism of the dye decomposition process is discussed.

Impacts of pH on photocatalytic efficiency, the control of energy and morphological properties of CuO nanoparticles for industrial wastewater treatment applications

Copper oxide nanoparticles were synthesised using a microwave oven method at different pH conditions (2, 5, 9, 12) in this study. FTIR, PL, FE-SEM, EDAX, XRD, TEM, XPS, and photocatalytic activity were used to investigate the prepared materials. The standard monoclinic structure of the CuO nanoparticle is seen by XRD. The FE-SEM image depicts an agglomerated spherical granular shape. A PL spectrum of copper oxide nanoparticles reveals three peaks at 362 nm, 528 nm, and 596 nm. The existence of CuO nanoparticles in the molecular structure was confirmed by FTIR. HRTEM images indicate spherical morphology at 100 nm, 50 nm, and 20 nm. The SAED diagram's diffraction rings matched nicely with the XRD diagram's peaks. The EDAX spectra confirm the presence of copper and oxygen in abundance in these nanoparticles. During a malachite green dye treatment, the highest pH concentration was 98.33 % higher photocatalytic activity than the other samples. According to the XPS study, the two satellite peaks at 939 eV to 946 eV and 959 eV to 965 eV show the formation of CuO with the oxidation state Cu (+2). As part of the application to meet the needs of the company, the samples were tested for the photocatalytic decomposition of malachite green industrial dye under the irradiation of a visible light source, and the samples demonstrated an excellent result in the waste water decomposition of industrial dye in a very short period of time.the band gap energy values were found to be 1.71, 1.70, 1.69 and 1.68 eV.

Photocatalytic decomposition of Congo red dye by black paste@TiO2 as an efficient recyclable photocatalyst

Abstract Manufacturing active and economical catalysts and using them in water treatment is one of the most important challenges facing researchers. Spent batteries signify a source of harmful materials when discarded without suitable treatment. In this work, a black paste as one of the main components of spent battery doped with different ratios of TiO2 nanocomposites (0, 1, 3, 7, and 10 %) were manufactured using the sol–gel method. The characterization of the paste@TiO2 nanocomposites has been investigated by SEM, XRD, DRS, FTIR, and BET analysis. The results show formation of anatase phase of TiO2 in all doped samples. While the XRD of black paste indicates the presence of Mn3O4 as a main phase. Photocatalytic properties of black paste@TiO2 nanocomposites have been investigated using Congo red dye. The results showed that the presence of TiO2 in the paste could increase the specific surface area and the composites’ photocatalytic efficiency. A higher percentage of TiO2 (10 %) added to the black paste resulted in higher black paste@TiO2 nanocomposite catalytic activity. The experimental photodegradation data were found to be consistent with the Lagergren kinetics model. The recyclability of the photocatalysts was examined for reuse in the industrial sector. Signifying that the black paste dopped with 10 % of TiO2 (PTO4) photocatalyst in this study had high reusability.

Initiation of piezoelectricity expands the photocatalytic H2 production and decomposition of organic dye through g-C3N4/Ag/ZnO tri-components

The enhancement of photocatalytic reactivity through the internal electric field has received much attention. The combination of the piezoelectric effect and the photo-exiting process facilitates the segregation of the photogenerated carriers, thereby boosting the piezo-photocatalytic activity. We have constructed g-C3N4/Ag/ZnO tri-component composites; with various g-C3N4 precursors to achieve reliable photo/piezo-photocatalysis for H2 production and Rhodamine B (RhB) dye degradation. We observed that urea-based g-C3N4/Ag/ZnO (UCAZ) tri-components exhibit a superior H2 production rate of 1125.5 μmol h−1 g−1 under photocatalytic conditions. When piezoelectric-potential was introduced into the photocatalysis reaction via ultrasonic, the H2 rate increased dramatically to 1637.5 μmol h−1 g−1, which is approximately 145% greater than that light irradiation alone.Similarly, the catalytic decomposition ratio of Rhodamine B (RhB) under the coexistence of ultrasound and light, and degradation efficiency reached 99% in 120 min, which is higher than the value of (42%, 0.0031 min−1) for piezo-catalysis and (80%, 0.01 min−1) for photocatalysis condition alone. The rate constant under synergisticsimulation reaches 0.021 min−1, which is 200% and 645% times higher than the sole light and ultrasonic illumination. Additionally, RhB degradation of all the tri-components was performed under solar light (Sunlight) and ultrasound irradiation, and efficiency reached 99.5% in 45 min with a rate constant of 0.06 min−1, which is 300% higher than the piezo-photocatalytic under LED source. The enhanced performance of the g-C3N4/Ag/ZnO tricomponent is attributed to the high specific surface area (168 m2 g−1) and synergetic effect of piezo catalysis and photocatalysis.

TiO2-loaded nanotubular kaolin group minerals: The effect of mineral support on photodegradation of dyes as model pollutants

One prevailing trend in order to design efficient photocatalysts is to support TiO2 on kaolin-based mineral carriers. This prevents TiO2 aggregation, improves textural parameters and adsorption properties as well as lowers costs. This research is a comprehensive comparison of photocatalysts based on different TiO2-loaded kaolin group minerals, including platy kaolinite, halloysite, halloysite-containing sample, and raw and calcined synthetic kaolinite nanotubes. The impregnation of the platy kaolinite sample led to the formation of star-like TiO2 aggregates, which were unevenly attached to the platelets surface. In contrast, the TiO2 formed nanocrystallites that homogenously covered the external surface of synthetic calcined kaolinite nanotubes. These differences had a significant impact on the textural properties of the resulting photocatalysts. The sample based on calcined nanotubes achieved a specific surface area of 257.1 m2/g, which was ∼4.5 times higher than the photocatalyst based on raw kaolinite. These distinctions influenced the photocatalytic performance of the materials in the decomposition of dyes. The comparison of the results to the commercial photocatalyst P25 highlighted the high potential of selected materials in the photodegradation of methylene blue and safranin O. The practical applicability and sustainability of the investigated materials was also attested via successful experiments on their regeneration and reuse.

Natural tourmaline for pyroelectric dye decomposition under 25–60 °C room-temperature cold-hot fluctuation

Tourmaline is a typical natural pyroelectric material. In this work, the pyroelectric property of tourmaline micro-powder is used to chemically deal with dyes wastewater under room-temperature cold-hot alternation. Under 25–60 °C heating-cooling cycles excitation, the decomposition ratio of Rhodamine B wastewater can achieve 84.7%. In the dye decomposition process, dissolved oxygen and hydroxide in the solution react with pyroelectrically induced positive and negative charges, respectively. This reaction triggers the production of superoxide radicals (O2–) and hydroxyl radicals (OH), which possess highly potent oxidation capabilities towards dye molecules. This work highlights the potential application of tourmaline mineral for dye decomposition in harvesting the environmental cold-hot alternation heat energy in future.

Style decolorization treatment of denim fabric: Decomposition of indigo dyes via horseradish peroxidase/H2O2 system at room temperature

The decolorization treatment for denim fabric (jeans) could give the fabric a bright blue and white appearance, a sense of vintage, and meet the needs of different styles. In industrial production, the common decolorization methods included sphysical methods such as stone grinding and water washing, which can cause strong damage to the fabric, and chemical methods such as bleach washing and snow washing, which also have some problems of environmental pollution. Therefore, an efficient, clean, and controlled decolorization method for denim fabric was proposed using the horseradish peroxidase/H2O2 system, which was first reported in this article. The optimized decolorization treatment process was studied, and the optimal process was as follows: the dosage amount of horseradish peroxidase was 150 u/mL, the dosage amount of H2O2 was 2.5 mL/L and added 3 times, the pH of buffer solution was 5, the reaction temperature and time were 35 °C for 1 h. And controllable (local) decolorization of denim fabric was applied through printing methods. The decomposition mechanism and reaction kinetics of indigo by the horseradish peroxidase/H2O2 system was also analyzed and proved the indigo was decomposed into the isatin and some small molecule substances. In addition, compared with cellulase and laccase decolorization methods, the horseradish peroxidase/H2O2 system has the advantages of no anti-staining, high efficiency, and environmental protection. It was expected to become a promising partial style decolorization treatment method.

Annealing temperature-dependent CdS phase tunability in improving photocatalytic efficiency towards aquatic dye decomposition

Combinations of different materials can improve the functionality of a composite. Heterogeneous structures that consist of various crystalline phases in a single material may also improve the physical and catalytic properties. In this work, we have synthesized highly crystalline CdS with cubic, hexagonal, and heterogeneous phases through precipitation, followed by varying the annealing temperature. The photocatalytic degradation was performed on aqueous rhodamine 6G (R6G) dye as a model pollutant under UV irradiation. From the results, UV–Vis analysis revealed that the heterogeneous structure yields the most intense absorption with a reduced band gap, which is useful for improved photocatalytic reactions. The SEM image demonstrates that the heterogeneous CdS contains more tiny granule particles that disperse extensively over the surface. As a consequence, heterogeneous CdS shows enhanced photocatalytic degradation efficiency and rate constant, which may serve as a future photocatalyst for wastewater remediation.

A Post‐Spinel NaFeSnO4 as Novel Narrow Band Gap Photocatalyst for Visible Light Assisted Decomposition of Crystal Violet Dye

AbstractSnO2 is a wide bandgap photocatalyst, and Fe2O3 is susceptible to the recombination of photocharges produced is heterogenized in the form of NaFeSnO4. NaFeSnO4 with post‐spinel structure having one‐dimenisonal (1D) channel is explored first time as photocatalyst. Phase purity and structure of NaFeSnO4 was examined using X‐ray diffraction (XRD). Particle morphology, light absorption behavior, band‐gap energy estimation and surface area of NaFeSnO4 were evaluated using various instrumental techniques. Extent of charge separation and charge transfer was investigated using photoluminescence (PL) analysis and electrochemical impedance spectroscopy (EIS). Photocatalytic performance of NaFeSnO4 was examined for degradation of crystal violet dye by irradiating visible light. The photocatalytic properties of NaFeSnO4 are compared with the precursor oxides Fe2O3 and SnO2. It has been demonstrated first time that NaFeSnO4 is an efficient visible light active photocatalyst than Fe2O3 and SnO2 for degradation of crystal violet dye.