Degradation Of Tartrazine Research Articles

Highly effectual photocatalytic degradation of tartrazine by using Ag nanoparticles decorated on Zn-Cu-Cr layered double hydroxide@ 2D graphitic carbon nitride (C3N5).

Pollution of water resources is one of the main concerns of many countries. This issue originates from the entry of diverse pollutants, including dye compounds, into water sources. In this work, ternary Zn-Cu-Cr layered double hydroxides (LDH) supported on graphitic carbon nitride (g-C3N5) decorated by silver nanoparticles (C3N5-LDH-Ag) was first prepared. Application of various characterization techniques such as SEM, XRD, and FT-IR revealed that the synthesized nanocomposite was composed of Zn-Cu-Cr LDH nanoparticles, g-C3N5 nanosheets, and Ag nanoparticles. The prepared nanomaterials were employed for the photodegradation of tartrazine in aqueous solutions. It was found that the C3N5-LDH-Ag catalyst outperformed their pure g-C3N5, Zn-Cu-Cr LDH, and C3N5-LDH composite in photocatalytic degradation of tartrazine under visible light irradiation. Tartrazine (20mg/L) can be entirely removed by 0.25g/L C3N5-LDH-Ag photocatalyst under 1h visible light irradiation (200W) at pH 6 with a rapid degradation rate constant (k) that is 4.4, 3.9, and 2.6 times higher than that of pure C3N5, Zn-Cu-Cr LDH, and C3N5-LDH component, respectively. The formation of hydroxyl radicals on the surface of C3N5-LDH-Ag as the main active species was approved by the capturing experiment. The finding results approved the stability and reusability of C3N5-LDH-Ag in four photocatalytic degradation cycles. In general, our findings revealed that the synthesized nanocomposite could be employed as an efficient photocatalyst in environmental remediation.

Synthesis, design of experiments and optimization of heterogeneous Fenton-like degradation of tartrazine by MgFe2O4 nano-catalyst

In this work, magnesium ferrites nanoparticles (MgFe2O4 NPs) were successfully fabricated by sol-gel auto-combustion (SGAC) method and were used in heterogeneous Fenton-like degradation of tartrazine. The obtained products were characterized using XRD, FTIR, SEM and EDX. XRD studies confirmed that the synthesized MgFe2O4 NPs had a cubic spinel structure. The average crystallite size was evaluated using the Debyee Scherrer formula and found to be in the range 16.18–28.55 nm. In FTIR spectra, two primary absorption bands at 571 cm−1 and 415 cm−1 were observed. The spinel ferrites are characterized by these bands and the EDX confirms the presence of the desired elements Mg, Fe, and O. The influences of operating parameters were examined using the Box Behnken statistical design (BD), including magnesium ferrite dosage (0.04–0.12 g/L), tartrazine concentration (30–50 mg/L) and H2O2 concentration (3.53–7.06 mM). Using analysis of variance, a significant quadratic model was created. Optimum conditions were magnesium ferrite dosage of 0.092 g/L, tartrazine concentration of 30.21 mg/L and H2O2 concentration of 6.66 mM, respectively. The predicted degradation efficiency within the optimum conditions as established by the suggested model was 98.4%. Confirmatory tests were carried out and the degradation efficiency of 98.9% was observed, which was in good agreement with the model's prediction. After five recuperation and reapplications, the catalyst's degradation efficiency remains stable. These findings indicate that a heterogeneous Fenton-like process utilizing MgFe2O4 is effective in advanced wastewater treatment.

Facile synthesis of TiO2/g-C3N4 nanosheet heterojunctions for efficient photocatalytic degradation of tartrazine under simulated sunlight

In this study, TiO2/g-C3N4 nanosheet heterojunctions were successfully fabricated via a facile hydrothermal process and demonstrated to be effective catalyst for tartrazine (TTZ) degradation. The synthesized catalyst was characterized by several analytical methods, including TEM, XRD, UV-DRS, BET, FT-IR, PL, XPS and a series of electrochemical characterizations. The photodegradation of tartrazine (TTZ) under simulated sunlight by TiO2/g-C3N4 is reported for the first time. The TiO2/g-C3N4 composites displayed more excellent photocatalytic performance than pure g-C3N4 and TiO2. The effect of initial TTZ concentration, catalyst dosage, pH and impurity ions on the degradation efficiency were systematically investigated. Under the optimal experimental conditions, the degradation rate still remained about 93% even after 4 cycles, confirming the relatively stable activity of TiO2/g-C3N4. Besides, the free radical scavenging experiments demonstrated that superoxide radical (•O2−) and photogenerated holes (h+) were indispensable active substances for the TTZ degradation. Meanwhile, ultraviolet–visible spectroscopy analysis evidenced that the azo bond (NN) in the TTZ molecule was destroyed during the photocatalytic reaction. Finally, the reaction mechanism and specific steps of TTZ degradation have been inferred in detail. This study provided a valuable reference for the application of composite heterojunction materials in the degradation of pollutants under solar light.

Sol-gel auto-combustion synthesis of Cu1-xMgxFe2O4 nanoparticles and their heterogenous Fenton-like activity towards tartrazine

In this study, magnesium/copper ferrite nanoparticles Cu1-xMgxFe2O4 with composition (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were synthesized by sol–gel auto-combustion method. Samples were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). Subsequently, the nanoparticles were investigated as heterogeneous Fenton-like catalysts for tartrazine degradation in aqueous solution. Effects of experimental conditions of pH, tartrazine concentration, catalyst loading, H2O2 concentration and temperature were studied in detail. The catalytic activity of all Cu1-xMgxFe2O4 nanoparticles was compared at identical operational conditions. Among all the samples, Cu0.2Mg0.8Fe2O4 exhibited high catalytic activity, great stability and easily recyclable compared of pure CuFe2O4, MgFe2O4 and other Cu1-xMgxFe2O4 samples. Results indicated that 94.6 % of tartrazine was efficiently degraded by 0.2 g/L Cu0.2Mg0.8Fe2O4 with 239.9 mg/L H2O2 at pH = 3 and 30 °C during 120 min. Magnesium substitution enhanced the catalytic activity of copper ferrite (CuFe2O4) as the removal rate increased with an increase in magnesium content. Based on the experimental results, possible mechanism for the degradation of tartrazine was proposed. Hence, magnesium-copper ferrite can be used as effective catalysts for the destructive removal of organic pollutants in wastewater.

Designing, characterization, and evaluation of chitosan-zinc selenide nanoparticles for visible-light-induced degradation of tartrazine and sunset yellow dyes

Employing dyes in different industrial sectors has produced a serious threat to the environment and living organisms of water bodies and land. For the decontamination of such toxic dyes, efforts have been made to develop an efficient, feasible, and low maintenance processes. In this context, chitosan-zinc selenide (CS–ZnSe) nanoparticles were prepared through chemical reduction method as the efficient photocatalysts for the decontamination of toxic dyes through photocatalysis. Photocatalyst's synthesis was confirmed with the help of FTIR spectroscopy. XRD indicated the hexagonal crystal structure of the CS–ZnSe with a crystallite size of 12 nm. SEM micrographs showed the average nano photocatalyst size as 25 nm. EDX analysis was employed to determine the elemental composition of the CS–ZnSe. An excellent photocatalytic degradation efficiency for tartrazine and sunset yellow dyes was obtained using CS–ZnSe. The results showed a 98% and 97% degradation efficiency for tartrazine dye and sunset yellow (SY) dye at optimized conditions of time (3 h), pH (5), dye concentration (30 ppm), catalyst dosage (0.09 g and 0.01 g) , and at a temperature of 35 °C. Findings of the photocatalytic degradation process fitted well with first-order kinetics for both the dyes. Rate constant, ‘K’ value was found to be 0.001362 min−1 and 0.001257 min−1 for tartrazine and SY dyes, respectively. While value for (correlation coefficient, R2) was 0.99307 and 0.99277 for tartrazine and sunset yellow dyes, respectively. Recyclability of the photocatalyst was confirmed using it for consecutive cycles to degrade organic dyes. Results showed that the CH–ZnS possesses excellent efficiency in decontaminating organic dyes from industrial wastewater.

Performance of a C-containing Cu-based photocatalyst for the degradation of tartrazine: Comparison of performance in a slurry and CPC photoreactor under artificial and natural solar light

A carbon-containing Cu-based material (Cu@C) was used as photocatalyst for the degradation of a commonly food-industry azo-dye (tartrazine, also called Y5), under solar light at laboratory and pilot scale photoreactors. Important performance parameters such as dark adsorption capacity, catalyst́s loading and initial concentration of the dye were first optimized in a slurry photoreactor at laboratory scale under artificial solar light following the kinetics of degradation of the dye. Afterwards, the photocatalytic activity was investigated at pilot scale in a compound parabolic collector (CPC) photoreactor operating for 10 h of irradiation. The degradation of tartrazine is among the highest values reported for alternative metal oxide semiconductors, in both photoreactor configurations. Catalytic data revealed a 3 times faster degradation kinetics of tartrazine in the CPC photoreactor under natural solar light than in the slurry reactor under artificial solar light. This behavior indicates that a moderate photon flux in the CPC is more adequate to operate with the prepared photocatalyst, as it minimizes the recombination of charge carriers in the catalyst. This is important, since most of the photocatalytic tests designed to evaluate the activity of novel materials are frequently carried out under simulated solar light and disregard the impact of photon flux in outdoor conditions.

Degradation of Tartrazine Using Hydrodynamic Cavitation‐Based Hybrid Techniques and Fenton Chemistry

AbstractDegradation of the tartrazine was investigated systematically using the Fenton oxidation process and hydrodynamic cavitation (HC)‐based hybrid techniques. The operating parameters, such as the inlet pressure, the initial pH, the initial concentration of tartrazine, and the molar ratio of the Fenton reagents, were optimized. A maximum degradation of 12.50 % was observed using HC alone at 5 bar pressure and a solution pH of 2, while Fenton chemistry showed 92.40 % degradation at a Fe2+/H2O2 molar ratio of 1:36. HC in conjugation with H2O2 or Fenton reagents showed maximum degradation values of 92 and 96.40 %, respectively. The degradation follows a pseudo‐first‐order kinetics with respect to the concentration of tartrazine, for Fenton chemistry and the HC‐based hybrid techniques.

Heterogeneous Fenton-like degradation of tartrazine using CuFe2O4 nanoparticles synthesized by sol-gel combustion

In this work, copper ferrite (CuFe2O4) nanoparticles (NPs) were prepared by sol-gel auto-combustion method and were used for the degradation of tartrazine in aqueous solution by heterogeneous Fenton-like process. The NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and point of zero charge measurement (pHPZC). XRD confirmed the tetragonal spinel structure of CuFe2O4. The average particle size evaluated by Debye Scherrer equation was found to be 37.34 nm. FTIR spectrum shows two primary absorption bands characteristic of the spinel ferrites. The point of zero charge of the CuFe2O4 catalyst was about 6.9. Response surface methodology (RSM) was employed for the optimization of the degradation efficiency of tartrazine. Four important process parameters including catalyst loading (0.1–0.5 g/L), tartrazine concentration (30–50 mg/L), H2O2 concentration (35.28–70.56 mM) and temperature (30–50 °C) were optimized using the statistical Box-Behnken design. A quadratic model was developed and validated by the analysis of variances. Numerical optimization by desirability function was applied to identify the optimum conditions for maximum degradation efficiency of tartrazine. The optimum conditions were determined as 0.32 g/L of catalyst loading, 64.35 mM of H2O2, 30.63 mg/L of tartrazine concentration and 49.92 °C of temperature. The degradation efficiency of the catalyst remains stable after five times recovery and reuse.

Simple Preparation of the CuO•Fe3O4/Silica Composite from Rice Husk for Enhancing Fenton-Like Catalytic Degradation of Tartrazine in a Wide pH Range

SiO2 was prepared from rice husk (RH) with the assistance of cetrimonium bromide (CTAB), and the CuO•Fe3O4/SiO2 composite was prepared by a simple coprecipitation method to enhance the Fenton-like degradation of dyes in a wide pH range. SiO2 was a mesoporous material with a relatively large surface area of 496.4 m2/g and a highly relative pore volume of 1.154 cm3/g. The Fe3O4 and CuO particles with the size of 20–50 nm were well dispersed in the composite, making the composite tighter and causing the disappearance of large pores in the range of 20–55 nm. The surface area and pore volume of the composite were reduced to 248.6 m2/g and 0.420 cm3/g, respectively. Fe3O4/SiO2 and Fe3O4 samples only exhibited high catalytic activity in an acidic medium, while the CuO•Fe3O4/SiO2 composite could effectively work in a wide pH range of 3–7. Besides, the effects of reaction conditions such as catalyst dosage, H2O2 concentration, and initial dye concentration on the catalytic performance of the composite were studied. The optimal conditions for the degradation of dye were tartrazine (TA) concentration of 50 mg/L, dosage catalyst of 0.5 g/L, H2O2 concentration of 120 mM, and pH 5. The CuO•Fe3O4/SiO2 composite reached the highest activity at pH 5, showing a degradation efficiency (DE) of 93.3% and a reaction rate of 0.061 min−1. The reusability of the catalyst was investigated by cyclic experiments. The DE of the 3rd reuse remained at 55.1%, equivalent to 93.5% of the first use. The catalytic mechanism for the Fenton system has also been proposed.

Photocatalytic Performance of Carbon-Containing CuMo-Based Catalysts under Sunlight Illumination

Carbon-doped nanostructured CuMo-based photocatalysts were prepared by solvothermal synthesis. Two thermal treatments—oxidative and inert atmosphere—were used for the synthesis of the catalysts, and the influence of spherical carbon structures upon the crystalline phases on the photocatalytic activity and stability was studied. XRD showed the catalysts are nanostructured and composed by a mixture of copper (Cu, Cu2O, and CuO) and molybdenum (MoO2 and MoO3) crystalline phases. The catalysts were used for the degradation of yellow 5 under solar light. A remarkable leaching of Mo both in dark and under solar irradiation was observed and quantified. This phenomenon was responsible for the loss of photocatalytic activity for the degradation of the dye on the Mo-containing series. Conversely, the Cu-based photocatalysts were stable, with no leaching observed after 6 h irradiation and with a higher conversion of yellow 5 compared with the Mo- and CuMo series. The stability of Cu-based catalysts was attributed to a protective effect of spherical carbon structures formed during the solvothermal synthesis. Regarding the catalysts’ composition, sample Cu4-800-N2 prepared by pyrolysis exhibited up to 4.4 times higher photoactivity than that of the pristine material, which is attributed to a combined effect of an enhanced surface area and micropore volume generated during the pyrolytic treatment due to the presence of the carbon component in the catalyst. Scavenger tests have revealed that the mechanism for tartrazine degradation on irradiated Cu-based catalysts involves successive attacks of •OH radicals.

Visible-light photocatalytic degradation of tartrazine using hydrothermal synthesized Ag-doped TiO2 nanoparticles

Removal of organic pollutants from water using a low-cost approach is essential to safeguard against toxicity. Herein, the effect of silver ion doping on the photocatalytic activity of titanium dioxide (TiO2) towards the degradation of tartrazine (TA), a common food colourant and refractory water pollutant is reported. The hydrothermally synthesized nanomaterials were characterized using conventional physico-chemical techniques. The highest degradation of tartrazine (TA) (87%) was achieved within 180 min at an Ag doping concentration of 0.21% at room temperature. The study may be extended for the degradation of other similar organic pollutants in water.

Adsorption and catalytic degradation of Tartrazine in aqueous medium by a Fe-modified zeolite

Azo dyes, as Tartrazine (T), are one of the rawest materials in food, pharmaceutical and textile industries. Many dyes are difficult to degrade due to their complex structure and xenobiotic properties. Although adsorption is considered an effective, efficient, and economic method for water purification, degradation of organic pollutant like synthetic dyes by using advanced oxidation processes (AOPs), as Fenton process, has become increasingly significant during last decades. However, as Fenton process requires ferrous salt for the oxidation reaction to take place, the iron sludge formed after the reaction, has to be removed before discharging. A novel composite material, which is referred to as iron-loaded natural zeolite (NZ-A-Fe), was used for the removal of Tartrazine (T) from water through the combined adsorption and heterogeneous catalysis. Since the adsorption step determines the rate in heterogeneous catalytic processes, its study becomes necessary for understanding the degradation mechanism. The suitability of Langmuir and Freundlich isotherms to the equilibrium data was investigated in the solid-liquid system. The equilibrium adsorption capacity (qe) increases with the increase of the initial concentration of T. The pseudo-second-order model can well describe the adsorption process of T on NZ-A-Fe, where k2 = 0.246 g(mg.min)−1is the rate constant for adsorption process. Degradation kinetics can be described using the classical pseudo-first order. Tartrazine degradation was high between 90 and 95% for [H2O2] /[T] = 37 for [T] = 10 mg/L. The novelty of this work is the simultaneous adsorption and Fenton degradation using a supported catalyst NZ-A-Fe that facilitates the design of filters for wastewater treatment.

Cobalt-doped alumina catalysts in catalytic oxidation of tartrazine induced by Oxone®

Porous cobalt-doped alumina catalysts were synthetized using the sol-gel method. The synthesized materials were calcined at 500 °C, 1000 °C and 1100 °C and denoted as CoA-500, CoA-1000 and CoA-1100, respectively. Catalysts were characterized using XRPD, H2-TPR and low temperature N2 physisorption techniques. Applied techniques showed that the annealing temperature affects the structural and textural properties of the catalysts. The synthesized catalysts were investigated in the degradation of tartrazine in the presence of Oxone®. The influence of the mass of catalyst, reaction time, reaction temperature and initial pH were investigated. The temperature increase was beneficial for the dye degradation rate. CoA-500 was proved to be the most efficient among the investigated catalysts. The reaction followed the pseudo-first order kinetics for all investigated temperatures for all three catalysts. All cobalt-doped alumina catalysts were found to be efficient in the Oxone® induced catalytic degradation of tartrazine with CoA-500 showing the best performance.

A comprehensive study on the heterogeneous electro-Fenton degradation of tartrazine in water using CoFe2O4/carbon felt cathode

In this study, cobalt ferrite coated carbon felt (CoFe2O4/CF) was synthesized by solvothermal method and applied as cathode for electro-Fenton (EF) treatment of tartrazine (TTZ) in water. The materials were characterized by SEM, XRD, FTIR, CV, and EIS to explore their physical, chemical, and electrical properties. The effects of solvothermal temperature and metal content on the TTZ removal were examined, showing that 220 °C with 2 mM of Co and 4 mM of Fe precursors were the best synthesis condition. Various influencing factors such as applied current density, pH, TTZ concentration, and electrolytes were investigated, and the optimal condition was found at 8.33 mA cm−2, pH 3, 50 mgTTZ L−1, and 50 mM of Na2SO4, respectively. By radical quenching test, ▪, 1O2, and HO were recognized as the key reactive oxygen species and the reaction mechanism was proposed for the EF decolorization of TTZ using CoFe2O4/CF cathode. The reusability and stability test showed that the highly efficient CoFe2O4/CF cathode is very promising for practical application in wastewater treatment, especially for dyes and other recalcitrant organic compounds to improve its biodegradability.

Reduced graphene oxide impregnated in TiO2 for photodegradation of dyes monitored in UV-LED mini-reactor

The photocatalysts of rGO supported on TiO2 were obtained in situ by a sequence of an improved Hummers' method and an eco-friendly hydrothermal procedure. The XRD diffractograms did not present the signals corresponding with the rGO. However, they were detected in micro-Raman because of the characterized signals of D and G bands observed. From TEM, the rGO sheets were visualized covering the surface of TiO2. The photocatalytic experiments were conducted in a real-time monitoring UV-LED mini-reactor (3.0 mL, 5 W and λmax of 365 nm) with small aliquots of sample and catalysts. The catalysts were employed to photodegrade the organic dyes: methylene blue (MB) and tartrazine (TAR), as models or recalcitrant pollutants. The photocatalytic kinetic curves were described by first order kinetic model. Both dyes were completely degraded by all photocatalysts with up to 250 min of irradiation. All supported rGOTiO2 catalysts presented faster kinetics than the TiO2. For MB degradation, 1rGOTiO2 was 6× faster and for TAR degradation 1rGOTiO2 was 3× faster than TiO2. The main action of 1rGOTiO2 was attributed to the better charge transfer by the higher sp2 carbon domains. This result indicates that rGOTiO2 are promising photocatalysts for the degradation of recalcitrant organic pollutants.

Electrochemical and sonochemical advanced oxidation processes applied to tartrazine removal. Influence of operational conditions and aqueous matrix

Tartrazine degradation was investigated by electrochemical and sonochemical oxidation processes. Anodic oxidation was carried out using boron-doped diamond (BDD) electrodes. The influence of current density and dye initial concentration on the removal of tartrazine from water was analyzed. The experimental results indicate that total removal of tartrazine was obtained, and Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC) removals of up to 94.4% and 72.8% were achieved, respectively. To optimize the process, the pollutant removal percentage, the kinetic rate constant, and the TOC removal efficiency were chosen as target variables. Moreover, sonochemical oxidation experiments at a high-frequency range of cavitation (up to 1 MHz) were performed to establish the influence of three different operating variables, namely ultrasound frequency (0.5–1.1 MHz), ultrasound power (2.0–26.6 W ⋅L−1), and pulse-stop ratio (5:1–1:1). The process was also analyzed in terms of kinetics and energy costs. The kinetics resulted to be three times faster for the electrochemical process. However, the calculated energy costs were very similar, at least at long treatment times. Finally, the influence of three aqueous matrices was investigated. According to the experimental results, the natural occurrence of chloride and/or nitrate ions in water strongly conditions the rate of the process, although at least 90% of tartrazine removal was achieved within the first 50 min of treatment.

A novel approach in revealing mechanisms and particular step predictors of pH dependent tartrazine catalytic degradation in presence of Oxone®

The degradation of tartrazine in the presence of cobalt activated Oxone® (potassium peroxymonosulfate) was investigated at different initial pH values. Aluminum pillared clay had the role of a support for catalytically active cobalt oxide species. The degradation of tartrazine and the formation of a mixture of degradation products were monitored using the Ultraviolet–Visible (UV–Vis) spectroscopy and gas chromatography–mass spectrometry (GC-MS). The exact qualitative composition of this mixture and the determination of the most probable mechanism of degradation (the primary goal) were obtained using GC-MS. Besides, the main reaction pathway (reaction with SO4˙ˉ radical anion) and secondary pathways were proposed depending on the pH value. At pH = 6 the reaction with HO˙ radical was proposed. At pH = 11 decarboxilation was suggested as the first step of the secondary proposed reaction pathway. The combination of results acquired from the deconvolution of UV–Vis spectra and the theoretical UV–Vis spectra of degradation products, whose occurrence was predicted by quantum-chemical calculations, was proven to be beneficial for the identification of tartrazine degradation products and for defining UV–Vis predictors of particular degradation steps. An additional contribution of this paper, from the reactivity aspect, was the establishment of the critical structural demand for the radical degradation of any diazo compound. The existence of a hydrogen atom bound to a diazo group was found to be the essential prerequisite for the radical cleavage of diazo compounds.

Enhanced photocatalytic degradation of cationic and anionic dyes by Ag-modified g-C3N4 composite: Insights on different mechanisms under visible light

Ag/g-C3N4 was synthesized by thermopolymerization and photo-deposition methods, and the performance of Ag/g-C3N4 was evaluated by degrading cationic dye methylene blue (MB) and anionic dye tartrazine (TZ) under visible light. Results showed that the photocatalytic efficiency of Ag/g-C3N4 for MB and TZ was significantly improved compared with pristine g-C3N4. 80% of MB was removed in 120 min and TZ could be completely degraded in 90 min by Ag/g-C3N4. The improvement of photocatalytic efficiency can be ascribed to the better light absorption and lower recombination rate of e−/h+ after loading of Ag nanoparticles. The degradation efficiency of Ag/g-C3N4 for MB was improved as pH increased, while the efficiency for TZ was decreased at the same condition. This study also revealed the different photocatalytic mechanisms of MB and TZ. It showed that hole played a dominant role in degrading MB, while the degradation of TZ mainly relied on superoxide radical.

Facile Controlling of the Physical Properties of Zinc Oxide and Its Application to Enhanced Photocatalysis.

In this study, the physical properties of ZnO were facile controlled by the synthesis method with the addition of capping and precipitation agents. As-prepared ZnO samples had different morphologies such as carnation flower-like ZnO (CF-ZnO), rose-flower-like ZnO (RF-ZnO), rod-like ZnO (R-ZnO), and nanoparticle ZnO (N-ZnO) and were characterized by SEM, XRD, N2 adsorption/desorption isotherms, FT-IR, and DR/UV-vis. All samples had a crystallite structure of hexagonal wurtzite type. The CF-ZnO and RF-ZnO samples had the hierarchical structure like a carnation flower and a beautiful rose, respectively. R-ZnO was composed of many hexagonal rods and few spherical particles, while N-ZnO microstructures were made up of nanoparticles with approximately 20–30 nm, exhibiting the largest surface area, pore volume, and pore width among as-prepared samples, and their crystal size and bandgap energy were 17.8 nm and 3.207 eV, respectively. The catalytic performances of ZnO samples were evaluated by degradation of Tartrazine (TA) and Caffeine (CAF) under low UV irradiation (15 W). N-ZnO showed a high photocatalytic activity compared to other samples. Besides, the reaction kinetics was investigated by the first-order kinetic model, and the catalytic performance of ZnO was evaluated through several organic pollutants.

Penggunaan ZnO/zeolit sebagai katalis dalam degradasi tartrazin secara ozonolisis

An investigation on modification of natural zeolite with ZnO for the degradation of tartrazine. In this study, ZnO as a semiconductor is modified into a natural zeolite as support to form ZnO/zeolite that can increase the efficiency degradation of tartrazine. Further, the formed catalyst was added to tartrazine by determining the variation in ozonolysis time, the amount of addition of the catalyst, and the addition of a catalyst time. The results of degradation were determined by UV-Vis spectrophotometer at 424 nm. The result showed that the percentage of degradation obtained on each catalyst in the degradation. The resulted percent degradation of 20 ml of tartrazine at concentration of 15 mg/L using 20 mg ZnO/zeolite was 56.80%, while using 0.77 mg ZnO was 42.25%, and with the addition of 19.23 mg of Zeolite was 31.18%, all of that condition was proceeded by 40 minutes of ozonolysis. Thus, the result indicates that the ZnO/zeolite catalyst can increase percentages of tartrazine degradation by ozonolysis. It is known that the catalyst ZnO/zeolite is very effective in increasing the degradation of tartrazine. Analysis of tartrazine compounds using fourier-transform infrared spectroscopy (FTIR) after degradation changes in wavenumber indicates that there is a breaking of the bonds of tartrazine compounds. Characterization of ZnO/zeolite catalyst using FTIR, X-Ray diffraction (XRD) and scanning electron microscope (SEM), in each spectrum there was no shift, indicating that there is no change in ZnO/zeolite structure