Malachite Green Solution Research Articles

Zinc-Acetate-Amine Complexes as Precursors to ZnO and the Effect of the Amine on Nanoparticle Morphology, Size, and Photocatalytic Activity.

Zinc oxide is an environmentally friendly and readily synthesized semiconductor with many industrial applications. ZnO powders were prepared by alkali precipitation using different [Zn(acetate)2(amine)x] compounds to alter the particle size and aspect ratio. Slow precipitations from 95 °C solutions produced micron-scale particles with morphologies of hexagonal plates, rods, and needles, depending on the precursor used. Powders prepared at 65 °C with rapid precipitation yielded particles with minimal morphology differences, but particle size was dependent on the precursor used. The smallest particles were produced using precursors that yielded crystals with low aspect ratios during high-temperature synthesis. Particles produced during rapid synthesis had sizes ranging from 21-45 nm. The materials were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, thermogravimetric analysis, BET, and diffuse reflectance. The materials prepared using precursors with less-volatile amines were found to retain more organic material than ZnO produced using precursors with more volatile amines. The amount of organic material associated with the nanoparticles influenced the photocatalytic activity of the ZnO, with powders containing less organic material producing faster rate constants for the decolorizing of malachite green solutions under ultraviolet illumination, independent of particle size. [Zn(acetate)2(hydrazine)2] produced ZnO with the fastest rate constant and was recycled five times for dye degradation studies that revealed minimal to no reduction in catalytic efficiency.

Preparation and photocatalytic properties of β2-SiW11Mn/TiO2 nanomaterials

With manganese substituted heteropoly tungstate β2-K6[SiW11Mn(H2O)O39]·xH2O as the active component, a composite photocatalyst β2-SiW11Mn/TiO2 was prepared by impregnation method. The composite catalyst was characterized by FT-IR, UV-Vis, XRD, SEM and X-ray photoelectron spectroscopy. The catalytic activity was evaluated by the degradation of malachite green solution. The results showed that the degradation of malachite green under ultraviolet light reached 92.7% and the degradation effect under sunlight is better than that under ultraviolet light, reaching 97.2%. This indicates that polyoxometalates and titanium dioxide produced a synergistic effect to make the light response range expanded and reduced the reaction requirements. The catalytic degradation performance of pure titanium dioxide, heteropoly acid salt β2-SiW11Mn and the prepared catalyst β2-SiW11Mn/TiO2 on malachite green were studied. The results showed that the composite photocatalyst exhibited the best photocatalytic activity, confirming the significance of the material being compounded. Finally, the kinetics of the reaction were studied, and the reaction is a first-order reaction.

One-step rapid enrichment and detection of malachite green in aquaculture water based on metal-organic framework hydrogel

孔雀石绿是一种三苯甲烷类化合物,在水产品饲养中对疾病的防治有着不错的疗效,但因对人体健康有危害而被列为禁用药。由于实际样品中成分复杂,对于此类染料的检测方法难以同时兼具富集性好、灵敏度高且方便快速的优点。该工作制备了金属有机框架材料(MOF),采用MOF纳米材料掺杂的水凝胶(PAAM-SA/MOF)对养殖水体中的孔雀石绿进行吸附研究。采用一系列表征手段对MOF、PAAM-SA和PAAM-SA/MOF的微观形貌进行分析,结果表明吸附材料已成功合成。通过优化水凝胶吸附剂用量、吸附时间、孔雀石绿溶液pH、吸附温度、孔雀石绿溶液初始浓度等吸附萃取条件,使溶液中的孔雀石绿基本完全吸附在水凝胶中,在最优条件下,吸附效率最高可达97%。此外,采用不同极性的有机溶剂对吸附的孔雀石绿进行洗脱,通过优化洗脱液体积,脱附率最高达99%。在最佳条件下,该方法在高、中、低3个水平下的样品加标回收试验中回收率达到84.8%~118.1%,相对标准偏差小于5.1%,方法的检出限为0.083 μg/L(S/N=3),定量限为0.25 μg/L(S/N=10)。该方法简化了前处理过程,结合了MOF和水凝胶这二者各自的优点,添加的MOF材料可以在水凝胶体系中发挥其良好的吸附性,既解决了传统的MOF材料因粒径太小而回收率低的难题,便于吸附后直接提取,同时也解决了纯水凝胶吸附效率较低的问题,整体上提高了吸附效率和可回收性。实际样品测试表明该新型水凝胶吸附材料可用于养殖水体中孔雀石绿的快速萃取和检测,在食品检测领域具有很大潜力。

Study of the Fabrication of Gold Nanoparticle–Graphene-Arrayed Micro/Nanocavities as SERS Substrates Compared to Two Different Angles of Triangular Pyramid Tips

Surface-enhanced Raman scattering (SERS) has attracted attention because of its enormous potential to detect molecules with low concentrations. The method of fabricating SERS substrates is of great importance for improving the detection resolution. However, SERS substrates with different triangular pyramid tips fabricated by using the tip-based nanoindentation method has not been reported. Here, we prepared arrayed micro/nanocavities on copper-based graphene using the continuous indentation method with a Berkovich tip and a cube-corner tip, which have different face angles. Gold nanoparticles were then sputtered onto the graphene-copper micro/nanocavities to form the Au@GR@Cu micro/nanocavities SERS substrates. The substrates formed using the Berkovich tip and cube-corner tip were labeled B2-B9 and C2-C9, respectively, in which the numbers indicate the machining feed. Rhodamine 6G (R6G) was employed, and the Raman intensities of R6G on the differently arrayed Au@GR@Cu micro/nanocavities were measured. The Raman intensities of R6G were stronger on the pile-ups than on the inverted triangular pyramid cavities. The Raman intensities of R6G were highest on the C2 and B2 structures and lowest on the C9 and B9 structures. The Raman intensities of R6G on the arrayed Au@GR@Cu micro/nanocavities fabricated by the cube-corner tip were stronger than those on the arrayed Au@GR@Cu micro/nanocavities fabricated using the Berkovich tip with the same machining feed. In addition, the electric field intensity and distribution of the B9 and C9 arrayed Au@GR@Cu were simulated using Comsol software. Au@GR@Cu structures fabricated by the cube-corner tip were generated with higher electric field intensities. Furthermore, the relative standard deviations at 1362 cm-1 of R6G were 6.19 and 6.62% on the C2 and C4 surfaces, respectively, showing good homogeneity. The SERS spectra of 10-9 mol/L malachite green solution and 10-6 mol/L carbaryl solution were recognized on the C1, C2, and C4 surfaces on day 1 and after 3 months, respectively. After storage at room temperature for 3 months, the reductions in the Raman intensities were less than 10%, indicating excellent stability. The results showed that the arrayed Au@GR@Cu micro/nanocavities fabricated using the cube-corner tip performed better than those fabricated using the Berkovich tip and exhibited excellent uniformity, availability, and stability, providing great potential for detecting pesticides at low concentrations.

Synthesis and characterization of magnetic carboxymethyl chitosan‐poly(acrylic acid‐itaconic acid) hydrogel for the efficient adsorption of malachite green

AbstractA new type of magnetic hydrogel (Fe3O4/CMC‐co‐p[AA‐IA]) adsorbent was synthesized using magnetic carboxymethyl chitosan (CMC) matrix with acrylic acid and itaconic acid monomers by radical graft copolymerization and it was applied to the adsorption of malachite green (MG) aqueous solution. The chemical structural characteristics of hydrogel adsorbent were characterized by Fourier transform infrared spectra (FT‐IR), scanning electrons microscope (SEM), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), and X‐ray diffraction (XRD). These characteristics revealed that acrylic acid and itaconic acid monomers were successfully grafted onto the CMC backbone. Hydrogel adsorbent in deionized water has an excellent swelling ratio. To optimize the effect of various factors including pH, adsorbent dosage, ionic strengthen, initial concentration, contact time, and temperature on the adsorption capacity of MG dye were investigated in a batch. The adsorption equilibrium in the adsorption process follows the Langmuir isotherm adsorption and belongs to the monolayer adsorption. For describing the adsorption kinetics of MG dye, the pseudo‐second‐order kinetic model is more suitable appropriately than the pseudo‐first kinetic model. The thermodynamics model shows that the adsorption process is endothermic and spontaneous. After five cycles of adsorption and desorption, the hydrogel adsorbent also has better adsorption efficiency. These results show that the adsorbent has a better swelling capacity and a better adsorption performance.

Adverse effects of the toxic industrial dye malachite green on the antioxidant and antimicrobial properties of Allium cepa L.

The therapeutic importance of Allium cepa L. has been well established through ethnobotanical studies. Malachite Green is a highly toxic dye that finds extensive use in the textile industry as a fabric colorant. A. cepa was treated with malachite green solutions (20mg/l and 40mg/l) for 45 days. The roots actively take up malachite green and impede the plant's growth in root length, shoot length and fresh weight. A. cepa is rich in bioactive compounds, which have superior antioxidant and antimicrobial properties. We observe that the antimicrobial activities decrease by 36% for Staphylococcus aureus and 31% for Escherichia coli on the treatment of A. cepa bulbs with 40 mg/l malachite green. Antioxidant activity was similarly lowered by 61% under the toxic effects of the dye. Reduction in the efficacy of A. cepa in terms of the critical medicinal properties and general retardation in growth is a cause of concern. This article reports a previously unknown aspect of malachite green toxicity and presents the effect of any dye on the medicinal properties of A. cepa for the first time.

Layered MgAlFe hydrotalcite-like compounds for effectively degrading Malachite Green via Fenton oxidation

ABSTRACT The development of heterogeneous Fenton catalysts with good performance and stability is a challenge in the field of wastewater treatment. In this work, MgAlFe hydrotalcite-like compounds (MgAlFe-HTLcs) were prepared by solid phase reaction at room temperature and modified via a hydrothermal process. The experimental results showed that MgAlFe-HTLcs had a good layered structure with the same proportion of iron and aluminium, 18 h of crystallisation time and 110°C of crystallisation temperature and the lamellar structure was more uniform by solid grinding. Furthermore, the addition of iron can activate H2O2 more effectively to generate active oxygen which is •OH. The degradation experiments demonstrated that nearly 99.0% degradation efficiency was achieved for 10 mg/L Malachite Green (MG) solution within 60 min at the conditions of 0.10 g·L−1 MgAlFe-HTLcs, 0.10 mol·L-1 H2O2 and a natural pH of 6.3. Total organic carbon (TOC) removal reached 72.2% in a 70 min reaction. BET and XRD were measured to further discuss the stability and durability. Finally, a possible mechanism for the degradation of MG was presumed.

Facile green synthesis and biological evaluation of biogenic silver nanoparticles using aqueous extract of Alchornea laxiflora leaf

We report on the facile synthesis of biogenic silver nanoparticles (AgNPs) using aqueous leaf extract of Alchornea laxiflora for threefold applications in antibacterial screening, tyrosinase inhibition and photocatalytic degradation of malachite green dye solution experiments. Silver nanoparticles of an average size range of 20–52 nm and of spherical morphologies were obtained. The nanoparticles showed localized surface resonance bands within the range of 424 − 435 nm. The results of photocatalytic degradation experiment depict rapid photo-inspired degradation of 86% of the dye solution in less than a min and at a reaction rate of 0.136 min−1. The silver nanoparticles showed enhanced antibacterial activities against Escherichia coli and Staphylococcus aureus compared to the precursors. Complementary, dose-dependent tyrosinase inhibition activity with IC50 of 20.83 µg/mL and a competitive mode of inhibition was confirmed for the antityrosinase experiment involving the silver nanoparticles.

Photocatalytic performance of β-Ga2O3 microcubes towards efficient degradation of malachite green

In this work, the photocatalytic degradation of malachite green (MG) solutions by β-Ga2O3 was investigated. The latter was synthetized by reacting gallium nitrate with concentrated formic acid, which produced gallium formate. The thermal decomposition of this compound at 850 °C produced single-phase β-Ga2O3. The resulting morphology corresponds to non-agglomerated microcubes, with a size in the range of 0.8 and 2.3 μm. The surface chemical composition and bandgap energy of this oxide were determined by X-ray photoelectron spectroscopy (XPS) and the Tauc method, respectively. The photodegradation of MG was carried out under violet light (λ = 405 nm), at room temperature, using the as-prepared powder. The results revealed a fast degradation of the dye during the first 20 min, which attenuates over time. The rate of photodegradation depends on the amount of β-Ga2O3 used and can be fitted by an exponential equation. The role of free hydroxyl radicals and reactive oxygen species in photocatalysis was addressed by using analytic techniques (FTIR and XPS).

Selective recognition and determination of malachite green in fish muscles via surface-enhanced Raman scattering coupled with molecularly imprinted polymers

Molecularly imprinted polymers (MIPs) were incorporated with surface-enhanced Raman scattering (SERS) for selective recognition and rapid detection of malachite green in fish muscles. Among four functional monomers, methacrylic acid was selected as the suitable one for MIPs synthesis based upon computational simulation. The optimized MIP exhibited a higher adsorption efficiency for malachite green than that of nonimprinted polymers. The 74 nm gold-silver core-shell nanoparticles (Au@Ag NPs) provided stronger SERS signals for malachite green than those of other eleven gold nanoparticles and Au@Ag NPs. The use of selected MIP with Au@Ag NPs enabled to detect as low as 0.5–1 ng/g of malachite green in fish muscles from three different species, which was similar to that of 0.5 μg/L for malachite green standard solutions. The limit of detection was 0.37–0.64 ng/g in different fish muscles. This study provided a rapid, selective, and sensitive approach for SERS analysis of malachite green in aquatic products. • Surface-enhanced Raman scattering (SERS) used for malachite green (MG) detection. • Molecularly imprinted polymers (MIPs) designed to capture MG via computer simulation. • From 12 metallic colloid, Au@Ag (dia. 74 nm, seed 43 nm) chosen as a SERS substrate. • As low as 0.5–1 ppb MG in fish muscles detected with MIP-SERS hybrid method. • Interference of sample matrix effects minimized via MIP for SERS detection of MG.

Toward quantitative SERS detection in low analyte concentration by investigating the immersion volume and time of SERS substrate in analyte solution

AbstractThe strength of SERS signal depends on the amount of analyte adsorbed onto the hotspots of a SERS substrate immersed in solution. This adsorption is a dynamic process and can be described by the Langmuir adsorption model, in which the adsorption is influenced by several factors such as the temperature and the immersion time. By varying the immersion time and immersion volume of a gold nanostructure array SERS substrate in malachite green solution, we find that the required immersion time to reach the equilibrium adsorption coverage increases with decreasing analyte concentration and volume. For a 6.5 mm × 6.5 mm SERS substrate immersed in 15 ml of 1.5 ppb malachite solution, it takes more than 7 days of immersion time for it to reach 63% of the equilibrium coverage in ambient environment. Furthermore, at low concentration and immersion volume, the solution concentration decreases during the adsorption process and causes deviation from the prediction of Langmuir isotherm. In this work, we demonstrate that for quantitative SERS measurement in low analyte concentration, it is critical to take the immersion volume and time into consideration and ensure the equilibrium adsorption coverage or SERS intensity is reached for accurate concentration determination.

Ultrasensitive SERS detection of crystal violet and malachite green based on high surface roughness copper nanocorns prepared via solid-state ionics method

Copper nanostructures with quantum size effect and low preparation cost have broad prospects in detecting signal molecules, conducting films, manufacturing catalysts and improving antibacterial activity. A novel macroscopic dendritic copper nanocorns with the length of 2–50 mm prepared by solid-state ionics method at 8 μA direct current electric field (DCEF) using fast ionic conductor RbCu4Cl3I2 films was reported. The surface-enhanced Raman scattering (SERS) performance of prepared copper nanocorns was detected by crystal violet (CV) and malachite green (MG) aqueous solution as analyte molecules. The results present that many regularly arranged nanoparticles with the diameter from 15 to 40 nm existed on the prepared copper nanocorns, which lead to the nanocorns have high surface roughness. The copper nanocorns contain only Cu elements, no O element and the fractal dimensions of copper nanocorns was 1.411 because of macroscopic dendritic structures. The prepared copper nanocorns composed of pure Cu have high surface roughness and a large number of hot spots formed on the surface of copper nanocorns, so the limit of detection (LOD) for CV and MG detected by copper nanocorns were as low as 1 × 10−13 mol/L and 1 × 10−14 mol/L, respectively. The centimeter-scale and high surface roughness copper nanocorns with high purity copper, simple detection procedure, low LOD of analyte molecules and facile material synthesis have strong application prospect in detection of harmful additives in food.

Enhancing sensitivity in absorption spectroscopy using a scattering cavity

Absorption spectroscopy is widely used to detect samples with spectral specificity. Here, we propose and demonstrate a method for enhancing the sensitivity of absorption spectroscopy. Exploiting multiple light scattering generated by a boron nitride (h-BN) scattering cavity, the optical path lengths of light inside a diffusive reflective cavity are significantly increased, resulting in more than ten times enhancement of sensitivity in absorption spectroscopy. We demonstrate highly sensitive spectral measurements of low concentrations of malachite green and crystal violet aqueous solutions. Because this method only requires the addition of a scattering cavity to existing absorption spectroscopy, it is expected to enable immediate and widespread applications in various fields, from analytical chemistry to environmental sciences.

Adsorption Kinetics of Malachite Green Dye Removal from Aqueous Solution by using Banana Stem

This research work goals at searching the effectiveness of Malachite Green dye removal using banana stem, an agricultural waste as an activated carbon. The banana stem activated carbon was made ready in the laboratory by carbonization followed by activation. Adsorption studies were carried out to check the effect of various experimental conditions like different pH values, varying contact time, initial concentration of dye and changing banana stem carbon dosage on the removal of Malachite Green dye from aqueous solution at constant Temperature and agitation speed. The equilibrium experimental data were used for applicability of Langmuir and Freundlich isotherm models and the kinetic models. Batch test showed that maximum of 99% of dye was removed when the dye concentration was 2 mg/L, at an adsorbent dose of 0.75 gm/L at dye pH 8 in 45 minutes. From the obtained results it is validated that the equilibrium data’s favorable for both Freundlich and Langmuir isotherms. Maximum adsorption capacity of banana stem carbon on malachite green dye was found to be 8.29 mg/g. It was prevailing that the adsorption process followed the pseudo-second-order rate kinetics. It was observed that intra particle diffusion is not the only rate-limiting step in this adsorption system but also regression results indicate that the linear regression model gives the best results. The above observations recommend that Banana stem carbon can be competently implemented for removal of malachite green dye from aqueous solution in the adsorption treatment processes.

Fabrication of reusable polymer nanocomposite films made of thermoplastic polyurethane and modified BiVO4 for photodegradation of Malachite Green

Semiconducting BiVO4, is successfully prepared by solid-state route and attempts are taken to dope vanadium sites by titanium ions to produce BiV1-xTixO4 (x = 5%, 10% and 15%). The products are analyzed using powder X-ray diffraction, Raman spectroscopy, scanning electron microscopy and energy dispersive spectroscopy. The average particle sizes are in the range of 71-82 nm. Using diffuse reflectance spectroscopy, the band gaps are estimated and fall in visible range (2.11-2.41 eV). These nanomaterials are investigated for the photodegradation of malachite green dye solution that can find application in wastewater treatment and their efficiencies are investigated by time-dependent UV-Visible spectroscopy. 15% titanium doped BiVO4 (BVO-15) showed the highest efficiency by completely degrading malachite green in 180 min under visible light irradiation. In such heterogenous processes, separation of the used nanocatalysts remain a challenge. To address this, reusable polymer nanocomposite films are prepared using thermoplastic polyurethane (TPU) to immobilize BVO-15. The polymer nanocomposite film with 0.10 g of catalyst in 1 g of TPU showed maximum efficiency (~ 96%). The powder and film catalysts are investigated for three cycles and found to be effective. Thus, they show remarkable photocatalytic activity, stability and reusability that make them suitable for the wastewater treatment.

Facile chemical fabrication of Ni doped CoAl2O4 nano-spinel photocatalysts: Physico-chemical properties and photodegradation of toxic malachite green dye under visible light

ABSTRACT In this present study, we report the facile chemical fabrication of Ni-doped CoAl2O4 (NCA) (Co1-xNixAl2O4-δ, where x = 0.0, 0.05, 0.10, 0.15 and 0.20) nano-spinel photocatalyst materials by a simple chemical precipitation route. The XRD data revealed the presence of cubic crystal structure for CoAl2O4 and Ni-doped CoAl2O4 samples. Presence of vibration modes of M − O, Al−O, and M − O− Al in the spinel lattice structure in the materials was found out by FTIR analysis. The particle size analysis and SEM confirmed the presence of nanosized grains in the samples. The occurrence of appropriate amount of Co, Al, O and Ni was detected by EDAX analysis. The optical characteristics of Co1-xNixAl2O4-δ were studied using UV spectral studies. The band gap energy (Eg) of NCA was found to be in the range of 2.14 to 2.32 eV. The photocatalytic activity studies confirmed that the fabricated NCA nanoparticles have good photocatalytic behaviour in the degradation of malachite green (MG) dye solution under visible light irradiation. Further, the obtained results revealed that the doping of Ni has influenced the structural, spectral, morphology and the photocatalytic properties of the CoAl2O4 spinel materials to a greater extent. In addition, the factors affecting the photo-degradation of MG including composition of photocatalyst, photocatalyst loading, pH of the dye solution and the irradiation time were investigated and reported. The studies indicate that the 15% Ni-doped CoAl2O4 is a promising candidate material among all for the photocatalytic degradation of highly toxic dyes such as MG.

Visible Light-Driven Photocatalytic Activity of Magnetic Recoverable Ternary ZnFe2O4/rGO/g-C3N4 Nanocomposites

ZnFe2O4/rGO/g-C3N4 ternary nanocomposite photocatalysts with different ZnFe2O4/g-C3N4 weight ratio (0.5, 0.75, 1) were prepared by a stepwise solvothermal method using ethylene glycol as the solvent. Physicochemical methods such as X-ray diffraction, UV-Vis diffuse reflectance spectroscopy and photoluminescence spectroscopy were applied in order to characterize the composites. The formation of a meso-/macroporous structure with specific surface area between 67 and 77 m2 g–1 was confirmed by N2 adsorption/desorption. The bandgap of the composites was found to be lower (2.30 eV) than that of g-C3N4 (2.7 eV). In contrast to pure g-C3N4, the composites showed no fluorescence, i.e. no recombination of e–/h+ took place. All samples, including pure g-C3N4 and ZnFe2O4, were tested for adsorption and photocatalytic degradation of aqueous malachite green model solutions (10–5 M) under visible light irradiation (λ > 400 nm). The results show that the prepared nanocomposites have higher absorption and photocatalytic activity than the pristine g-C3N4 and ZnFe2O4 and can be successfully used for water purification from organic azo-dyes.

Synthesis of Gd doped TiO2 Thin Film for Photocatalytic Degradation of Malachite Green

In this research work, a simple spray pyrolysis method was employed to synthesized gadolinium (Gd) doped titanium oxide (TiO2) thin film. The crystal structure and morphology of the sample was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). According to XRD measurements, no apparent crystal peak was observed. The thickness of the prepared film was found to be 228 nm from SEM observation. The optical transmittance and bandgap energy of the synthesized thin film was investigated by using UV-Vis spectroscopy. The high transmission of the thin film was found in the visible region. The optical bandgap energy of the prepared film was found to be 2.85 eV. The photocatalytic degradation of malachite green solution was studied. As a result of the photocatalytic experiment, the thin film could be used as an effective photocatalyst for malachite green dye.

Synthesis and characterization of Ni-doped anatase TiO2 loaded on magnetic activated carbon for rapidly removing triphenylmethane dyes.

In this work, we employed the in situ synthesis method to implant Fe3O4 into activated carbon (AC), in which the synthesis of the magnetic AC (MAC) was realized. Thence, Ni-doped anatase TiO2 (NATiO2) were anchored on different addition amount of MAC to synthesize the series of Ni-TiO2/MAC photocatalysts. The chemical compositions and physical properties of these nanocomposites were analyzed by various characterization technologies. The photocatalytic capabilities of as-produced materials were then investigated via adsorption and photodegradation of triphenylmethane dyes (TPMs) as crystal violet (CV), basic fuchsine (BF), and malachite green (MG) solution. The results revealed that the removal of Ni-TiO2/AC, Ni-TiO2/2MAC, Ni-TiO2/4MAC, and Ni-TiO2/8MAC on TPMs is a very fast process and the removal efficiency can almost reach to about 90% in 10min, and the catalyst has good cycle stability and is easy to be reused. This work provides a novel, low-cost, and effective way to rationally design and synthesize TiO2-based photocatalysts for effective removal of TPMs.

Green Synthesis of Biogenic Zinc Oxide Nanoflower as Dual Agent for Photodegradation of an Organic Dye and Tyrosinase Inhibitor

In the study, metabolites of Euphorbia sanguinea were used as benign reducing and stabilizing agents to obtain zinc oxide nanoparticles (ZnO-NPs). The nanoparticles were evaluated as dual agent for photodegradation of Malachite green dye and tyrosinase inhibitior of mushroom tyrosine enzyme. Surface plasmon bands and energy band gaps of the ZnO-NPs were within the range 356–378 nm and 2.72–4.37 eV respectively as obtained from the UV–Vis spectra. SEM/EDS elemental mapping of the nanoparticles gave flower-like shape and even distribution of zinc and oxygen. XRD result revealed crystallographic peaks assigned to hexagonal phase of zinc oxide. The metal oxide nanoparticles were used to achieve 53% percentage degradation of Malachite green dye solution in less than a minute of solar radiation, which increased to 92% in 60 min. A first order kinetics with correlation coefficient R2 of 0.937, rate constant of 0.0084 min−1 and half-life of 82.52 min was established for the photodegradation process. The ZnONPs exhibited good tyrosinase inhibition with IC50 of 49.016 µg/ml. The mode of enzymatic inhibition was competitive with an inhibition constant (Ki) of 0.525 mM using Lineweaver–Burk kinetic model.