Degradation Of Brilliant Green Dye Research Articles

Impact of Co-Doping on the Visible Light-Driven Photocatalytic and Photoelectrochemical Activities of Eu(OH)3.

The microwave-assisted synthesis approach was used to synthesize Eu(OH)3 and Co-Eu(OH)3 nanorods. Various techniques were used to investigate the structural, optical, and morphological features of the Eu(OH)3 and Co-Eu(OH)3 NRs. Both Eu(OH)3 and Co-Eu(OH)3 NRs were found to be hexagonal with crystallite sizes ranging from 21 to 35 nm. FT-IR and Raman spectra confirmed the formation of Eu(OH)3 and Co-Eu(OH)3. Rod-shaped Eu(OH)3 and Co-Eu(OH)3 with average lengths and diameters ranging from 27 to 50 nm and 8 to 12 nm, respectively, were confirmed by TEM. The addition of Co was found to increase the particle size. Furthermore, with increased Co doping, the band gap energies of Co-Eu(OH)3 NRs were lowered (3.80-2.49 eV) in comparison to Eu(OH)3, and the PL intensities with Co doping were quenched, suggesting the lessening of electron/hole recombination. The effect of these altered properties of Eu(OH)3 and Co-Eu(OH)3 was observed through the photocatalytic degradation of brilliant green dye (BG) and photoelectrochemical activity. In the photocatalytic degradation of BG, 5% Co-Eu(OH)3 had the highest response. However, photoelectrochemical experiments suggested that 10% Co-Eu(OH)3 NRs showed improved activity when exposed to visible light. As a result, Co-Eu(OH)3 NRs have the potential to be a promising visible-light active material for photocatalysis.

Experimental and theoretical study on the photocatalytic degradation of brilliant green dye by N-doped Zn2GeO4

In this study, experimental and theoretical insights on the photocatalytic degradation of BG in an N-doped Zn2GeO4/UV irradiation system were explored. Kinetic experiments, degradation mechanisms analysis, and toxicity evaluation of intermediates were involved. The catalytic performance of N-doped Zn2GeO4 was optimum when the molar ratio of CO(NH2)2 and GeO2 is 1: 1. BG was almost 100% degraded within 10 min. Catalyst dosage and initial concentration had effects on the photodegradation of BG. Materials Studio calculations indicated that the nitrogen atoms are interstitially doped into Zn2GeO4 in the form of Zn–N–Ge. The N 2 s orbital contributes more than the N 2p orbital to the PDOS of N-doped Zn2GeO4, suggesting the difficult recombination of e- and h+. According to mass spectrometry analysis, de-ethylation, hydroxylation, condensation, carboxylation, and ring-opening were the main photocatalytic degradation pathways of BG. ∙OHs and O2∙-s played important roles in the Hg lamp/N-doped Zn2GeO4 reaction system, while h+ was existed in this system using quenching experiments. The 2FED2HOMO and (FED2HOMO + FED2LUMO) values implied the locations vulnerable to attack by free radicals of BG, which validated the reasonableness of the LC-MS/MS analysis result. Toxicity evaluations by the ECOSAR program suggested that photocatalytic degradation can exacerbate the aquatic toxicity of BG in the initial stage.

Chemically synthesized manganese oxide nanorods for effectual organic dye removal and energy storage application

Manganese oxide nanoparticles (MnO2) are successfully synthesized by using a facile chemical co-precipitation and reflux-assisted co-precipitation method with varying annealing temperatures and reflux time respectively. The synthesized samples' structural, optical and thermal properties are investigated by XRD, FTIR spectra, Ultraviolet–Visible spectroscopy, Thermogravimetric Analysis and BET surface area analyzer. The average crystallite sizes assessed by Scherrer's equation (Williamson- Hall plot) of prepared samples are in the range of 6–8 nm (6–7 nm) for the reflux-assisted method and 15–30 nm (20–46 nm) for the co-precipitation method respectively. The presence of peaks associated with Mn-O bonds in FTIR spectra confirmed the formation of MnO2 nanoparticles. FESEM studies revealed the nanorod-type morphologies of samples. The prepared samples showed pseudocapacitive behaviour and significant photocatalytic degradation of brilliant green dye.

A step towards enhancing the efficiency of biofilm mediated degradation of brilliant green dye in packed bed bioreactor: Statistical and toxicity analysis

This study aims to investigate the biodegradation of brilliant green (BG) dye in a packed bed bioreactor (PBBR) using Bacillus lichenifomis immobilized polyurethane (PU) foam as support material. The operating process parameters (e.g., pH, dye concentration, and inoculum dose) were optimized using response surface methodology (RSM) and artificial neural network (ANN). A sensitivity analysis reveals that pH has comparatively more significance (46 %) than the other parameters. Further, PBBR was continuously operated at various inlet feed flow rates (10–50 mL/h) under optimum conditions for 60 days. Maximum removal efficiency (RE) and elimination capacity (EC) were found to be 91.2 % and 88.0 mg/L.d, respectively. Monod and Andrews-Haldane models were applied for kinetic study and kinetics parameters μmax and Ks was found to be 0.125 per day and 38.9 mg/L for Monod and 0.175 per day and 45.1 mg/L for Andrew – Haldane model respectively. UV–vis and FTIR analysis confirmed the successful biodegradation of BG dye. Stress caused by BG dye was assessed by chlorophyll (a and b) and carotenoid content. Superoxide dismutase (SOD) activity was analyzed for biologically treated samples. Bacterial toxicity study reveals that biologically treated samples showed significantly less bioluminescence inhibition.

The influence of activated carbon annealing temperature on sunlight-driven photocatalytic dye degradation and biological activity

• AC nanoparticles were synthesized through the use of Jasminium flower extract . • The optimum conditions for the 96 % removal of MB was obtained at 600 o C. • AC photocatalyst could be recycled up to 5 times without losing its stability for the dye. • The Industrial pollutant, MB had a 96 % degradation. In this study, activated carbon (AC) produced from jasmine flowers was effectively manufactured using a hydrothermal carbonization procedure at various annealing temperatures. The XRD pattern revealed the graphitic phase of carbon. The surface morphology of nanoparticles exhibits uneven shapes. To investigate the photocatalytic activity of methylene blue (MB), it was photodegraded using visible light irradiation. Under solar light irradiation, the prepared activated carbon was used as a potential photo catalyst for the photo catalytic degradation of brilliant green dye, which revealed 96 % degradation. The antibacterial activity of activated carbon was tested against S. Aureus ( MTCC-737) and E. coli (MTCC-443) microbial pathogens, and the zone of inhibition layer was studied. To the best of our knowledge this is the first study to use jasmine flower based AC as a photocatalyst for the efficient breakdown of MB dye.

Photocatalytic efficiency of sol–gel synthesized Mn‐doped TiO2 nanoparticles for degradation of brilliant green dye and mixture of dyes

AbstractThe Mn‐doped TiO2 nanoparticle photocatalysts have been prepared by a simple sol–gel method. 1, 3, and 5 mol% Mn‐doped TiO2 nanoparticles have been prepared by using a stoichiometric amount of manganese acetate and titanium isopropoxide as precursors of Mn and Ti respectively. The physico‐chemical characterization of the prepared samples has been studied by x‐ray diffraction (XRD), Brunauer–Emmett–Teller surface area analysis, field emission scanning electron microscope, energy dispersive x‐ray analysis, high‐resolution transmission electron microscopy, x‐ray photoelectron spectroscopy, Ultraviolet–visible spectroscopy, photoluminescence spectroscopy, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). XRD study reveals the formation of pure anatase phase of TiO2 and decrease in crystalline size of TiO2 on increasing the Mn doping content. TGA reveals minimum weight loss in the high‐temperature region of 500–1,000°C, showing the thermal stability of the catalyst. FTIR study shows highly bonding in metal atoms. These samples have been tested for photocatalytic degradation of brilliant green dye. 5 mol% Mn‐doped TiO2 is having nearly four times more photocatalytic activity than pure TiO2. In addition, Mn‐doped TiO2 has shown excellent photodegradation of a mixture of three dyes namely, rhodamine B, brilliant green, and methylene blue.

Photocatalytic mineralization of brilliant green dye using bimetallic CeCuO3 nanoparticles in LEDs irradiations: A green and economically viable approach

The use of bimetallic nanoparticles in photocatalysis is one of the prominent techniques for the treatment of wastewater. Pure and N, S-co-doped bimetallic cerium copper oxide nanoparticles were prepared and characterized by FTIR, X-ray diffraction and SEM. Newly synthesized N, S-co-doped CeCuO3 NP’s were used as photocatalysts for the degradation of Brilliant green dye in the presence of ecofriendly LEDs (250 W) irradiations. The values of rate constant for N, S co-doped and undoped CeCuO3 was observed individually. Brilliant green dye was effectively degraded by N, S doped CeCuO3 as compared to undoped CeCuO3 nanoparticles. Effect of doping and operating parameters e.g. pH, Intensity of light and amount of catalyst etc., on the rate of mineralization of dye was studied. Overall degradation of dye was confirmed by the determination of COD, CO2 and UV–Visible investigation of the samples. The mechanism of the mineralization of dye molecules was investigated by the formation of •OH radicals in the aqueous suspension. The reusability of catalyst was tested by different cycles.

Metallic nickel nanoparticles supported polyaniline nanotubes as heterogeneous Fenton-like catalyst for the degradation of brilliant green dye in aqueous solution

Metallic nanoparticles supported on porous matrices are promising heterogeneous catalysts for Fenton-like reaction towards the degradation of organic contaminants in water. Herein, novel magnetic nanocomposites (NCs) of metallic nickel (Ni0) nanoparticles and nanotubular polyaniline matrix (PANI/Ni0 NCs) were fabricated by simple reductive formation of Ni0 nanoparticles upon the pre-synthesized PANI nanotubes (NTs) surface and applied as heterogeneous Fenton-like catalyst in degrading cationic brilliant green dye (BG) in aqueous solution. Various physico-chemical characterization techniques revealed effective supporting of soft ferromagnetic well dispersed nano-dimensional Ni0 particles onto the PANI NTs matrix. Heterogeneous Fenton-like catalytic performance of PANI/Ni0 NCs for BG degradation in the presence of hydrogen peroxide (H2O2) oxidant demonstrated their superiority when compared with unsupported Ni0 nanoparticles counterpart. Experiments with a minimum 0.1 g/L of NCs and 10 mM of H2O2 displayed complete degradation of 100 mg/L BG within 120 min reaction time. Improved BG degradation was observed with increase in the dose of PANI/Ni0, H2O2 concentration and temperature, whereas it reduced with rise in initial concentration of BG. The rate of degradation was well described by the pseudo-first- order kinetic model. Six consecutive BG degradation experiments confirmed NCs reusability without loss of original (∼100%) degradation efficiency up to the fifth cycle. Finally, liquid chromatography–mass spectrometric (LC–MS) analyses of the BG samples after 120 min degradation time exposed the formation of N,N-diethylaniline as degradation product along with partial mineralization of the other end products via the attack of reactive hydroxyl radicals (HO•) produced in the catalytic system.

Enhanced persulfate activated sono-catalytic degradation of brilliant green dye by magnetic CaFe2O4 nanoparticles: Degradation pathway study, assessment of bio-toxicity and cost analysis

In this study, CaFe2O4 nanoparticles were successfully synthesized by a chemical precipitation technique and applied in persulfate (PS) activated sono-assisted degradation of brilliant green (BG) dye from aqueous medium. Vibrating-sample magnetometer (VSM) analysis revealed that CaFe2O4 nanoparticles have manifested magnetic properties, which aided in effortless separation of nanoparticles from aqua matrix after treatment. More than 99% BG dye degradation was observed under dye concentration of 50 mg/L, catalyst dose of 0.5 g/L, PS dose of 200 mg/L and in an ultrasound (US) irradiation time of 15 min. However, US alone treatment had shown BG degradation of only 40.7% whereas the efficiency was enhanced to ∼89% upon addition of CaFe2O4 in US system. The PS activated sono-catalytic dye degradation (US + CaF + PS) process was optimized using response surface methodology (RSM) with four experimental variables, i.e., CaFe2O4 catalyst dose, PS dose, dye concentration, and sonication time. The quadratic model developed using RSM was found to be successful in optimizing the process variables (R2∼0.983). The scavenging effects observed with sodium chloride and sodium sulphate on US + CaF + PS process have reduced BG removal efficiency from 98% to 93% and 89%, respectively, which affirmed that the free radicals play the fundamental role in BG degradation. In US + CaF + PS process, BG dye (m/z ∼ 385) was degraded to simpler products having m/z ratio of 215, 113 and 73. Moreover, the microtox bioassay results indicated that the formed intermediate products were non-toxic in nature, i.e., toxicity of BG dye reduced from 90.58 to 1.24% after treatment with US + CaF + PS system. The treatment cost of BG dye solution varied between 131.85 and 922.02 USD/Kg of BG dye removed; however, the RSM based model has predicted the optimal BG dye removal of 99.57% with treatment cost of 330.82 USD/Kg of BG dye removed. Finally, the outcome of reusability study revealed that the synthesized nanoparticles were recyclable with a removal efficiency of 80.1% even after five consecutive cycles.

Boosted sono-oxidative catalytic degradation of Brilliant green dye by magnetic MgFe2O4 catalyst: Degradation mechanism, assessment of bio-toxicity and cost analysis

The magnetic MgFe2O4 nanoparticles (NPs) were fabricated via a facile co-precipitation technique and was comprehensively characterized by XRD, FTIR, SEM, EDX and VSM. The prepared NPs were used as catalyst in presence of ultrasound (US) irradiation to activate persulfate (PS) for generation of sulfate radicals (SO4·-) for boosted degradation of toxic Brilliant Green (BG) dye. Preliminary experiments revealed that highest BG dye degradation efficiency of 91.63% was achieved at MgFe2O4 catalyst dose of 1.0 g/L, PS dose of 300 mg/L, and initial dye concentration of 70 ppm within 15 min of US irradiation. However, only US, US in presence of PS oxidation and US in presence of MgFe2O4 catalyst have shown 20.2%, 83.6% and 45.0% of BG dye removal, respectively. Furthermore, response surface methodology (RSM) based central composite design (CCD) was executed to investigate the effect of interaction between independent variables such as MgFe2O4 catalyst dose (0.5–1.5 g/L), PS dose (150–350 mg/L), initial BG dye concentration (50–150 ppm) and US irradiation time (4–12 min). The RSM based quadratic model was used to predict the experimental data, and the prediction accuracy was confirmed by analysis of variance (R2 = 0.98). The established RSM model has predicted the optimum experimental conditions as MgFe2O4 catalyst dose of 0.75 g/L, PS dose of 300 mg/L, initial dye concentration of 75 ppm and sonication time of 10 min. Subsequently, the treatment cost analysis was performed for all thirty experimental runs of CCD, and the RSM predicted response was found to be evidently optimum as this has delivered best economic condition (140 $/kg of BG removed) with respect to relative dye removal (%). COD removal and residual sulfate analysis have demonstrated satisfactory reduction of COD (90.31%) as well as sulfate ions (42.87 ppm) in the dye solution after treatment. Results of degradation pathway analysis portrayed the transformation of BG molecule (M/Z ratio 385) into simpler fractions with M/Z ratio of 193, 161, 73, and 61. Moreover, the toxicity analysis revealed that sono-catalytically activated PS system has efficiently reduced the toxicity level of BG dye from 93.9% to 5.13%.

A novel mechanochemical synthesis of Zn and N doped Tin (II) Sulphide nanoparticles and its photocatalytic activity by the degradation of Brilliant Green dye.

A novel mechanochemical method was used to synthesize the Zn (Metal) and N (Non-metal) doped and pure Tin (II) Sulphide. The synthesis was simply performed by hand grinding the reactants in mortar- pestle. The synthesised Zn and N doped Tin (II) Sulphide was characterised by the characterisation techniques SEM, EDX, XRD, UV-Visible Spectroscopy and photoluminescence Spectroscopy. The formation of nano size particles of the SnS was confirmed by SEM. The Elemental analysis was confirmed by Energy Dispersive X-Ray Spectroscopy. The band gap was calculated with the help of UV- Visible Spectroscopy. The photoluminescence property of Zn and N doped and pure SnS was studied by the Photoluminescence Spectroscopy. The Photocatalytic activity of doped and pure Tin (II) Sulphide was studied by the successful degradation of Brilliant Green dye. The factors pH and photocatalyst concentration have found a great effect on the photocatalytic activity of Zn and N doped Tin (II) Sulphide and pure Tin (II) Sulphide.

Microwave induced catalytic treatment of brilliant green dye with carbon doped zinc oxide nanoparticles: Central composite design, toxicity assessment and cost analysis

The potential of carbon doped zinc oxide nanoparticles (C-ZnO NPs) as a catalyst for microwave (MW) induced catalytic process (MW/C-ZnO NPs) was investigated for the degradation of brilliant green dye (BG). The synthesized C-ZnO NPs were characterized using XRD, FESEM, Raman, EDS, TGA and Zeta potential analysis. As a precursor, BG removal experiment was conducted at the initial BG dye concentration of 60 mg/L, C-ZnO NPs dose of 250 mg/L and MW irradiation of 10 min. In MW alone system, BG degradation of 47.7 % was observed in 10 min whereas introduction of C-ZnO NPs in MW system has enhanced the efficiency to ∼90 %. Subsequently, the effect of C-ZnO dose (0−500 mg/L), BG dye concentration (20−100 mg/L), and MW irradiation time (300−900 sec) on BG removal was evaluated using the central composite design (CCD) of experiments. Based on the experimental data, a quadratic model was developed and used for predicting BG removal. The analysis of variance (ANOVA) has confirmed that the model can predict accurately the BG removal within the experimental range (R2∼0.987). Using the CCD data, the cost-analysis was carried out and it has revealed that the optimum cost was 174 $/kg of BG removed at MW irradiation time of 7.0 min and BG concentration of 36.0 mg/L. Finally, LC–MS analysis was used to find BG degradation pathway and it showed that BG has degraded into simpler compounds. Moreover, micro-toxicity analysis demonstrated that MW/C-ZnO NPs treatment of BG has reduced the toxicity from 81 % to 10 % at 15 min exposure.

A study on Mn doped ZnO loaded on CSAC for the photocatalytic degradation of brilliant green dye

A favorable application to use Mn-doped ZnO NPs and loaded with a (0.5 g) small amount of cotton stalk activated carbon (CSAC) in photocatalytic degradation of BG dye. The impact of Mn-ZnO/CSAC has been studied by XRD, XPS, UV–Vis, FTIR, FE-SEM with EDAX, BET and EIS analysis. We found that just, Mn-ZnO/CSAC showed that the particle size, band gap is also reduced and increase surface area. There is an optimum Mn-doped ZnO/CSAC for the degradation efficiency of BG showed improved photocatalytic activity (97.47%) under sunlight irradiation at a catalytic dose of 0.20 g/L than Mn doped ZnO and pure ZnO NPs.

Size-dependent optical properties of MoS2 nanoparticles and their photo-catalytic applications

While two-dimensional (2D) layered MoS2 nanosheets have been extensively studied owing to their fascinating optoelectronic properties, less attention has been paid to the corresponding zero-dimensional nano-crystals. In this contribution, we report the efficacy of MoS2 nanocrystals for their size tunable properties for optical and photocatalytic applications. We have synthesized differently sized (10–70 nm) crystalline, hexagonal 2H-MoS2 nanoparticles (NPs) dispersed in DMF solvent using a simple exfoliation technique. Synthesized NPs are found to exhibit size-dependent optical properties and excitation-dependent fluorescence characteristics in the visible region, which are otherwise not observed in bulk or 2D MoS2 layers. Size tunable bandgap and broad absorbance and emission spectrum covering the visible range could be exploited in the fabrication of various opto-electronic devices. Charge carrier emission dynamics of differently sized MoS2 NPs are investigated using time correlated single photon counting (TCSPC) spectroscopic technique. We found two time components, one in the order of several hundreds of ps, which arises due to the radiative recombination of charge carriers, while the other one is of the order of a few ns, which emanates from the defect states of MoS2 NPs. The average time constants are found to decrease with increase in particle size. A noticeable photocatalytic activity of the synthesized MoS2 NPs under visible light illumination for the degradation of brilliant green dye is also demonstrated for the first time and the effect of size variation of NPs in the dye degradation process is reported.

Singular properties of boron-doped diamond/carbon fiber composite as anode in Brilliant Green dye electrochemical degradation

Carbon fiber (CF) and boron doped diamond/carbon fiber (BDD/CF) were applied as anodes for the Brilliant Green dye electrochemical degradation process. CF substrates were obtained from polyacrylonitrile precursor heat treated at 1000 °C in a nitrogen atmosphere. BDD films were grown on CF substrates by hot filament chemical vapor deposition with boron source from an additional hydrogen line passing through a bubbler containing B2O3 dissolved in methanol solution with B/C ratio of 15,000 ppm. The electrodes were characterized by field emission gun-scanning electron microscopy images, Raman spectroscopy, and electrochemical impedance spectroscopy showing notable tridimensional characteristics besides their high diamond quality. They were applied to electrochemical degradation of Brilliant Green dye at different current densities using a concentration of 100 mg L−1. Their electrolysis efficiency was analyzed by UV/Vis spectrophotometry technique. The results showed that BDD/CF electrodes were efficient in the solution color removal, regardless of the current density value. BDD/CF electrode under the lowest current density of 10 mA·cm−2 presented the best performance with higher kinetic constant and color removal percentage associated to its low energetic consumption.

Enhanced solar light-mediated photocatalytic degradation of brilliant green dye in aqueous phase using BiPO4 nanospindles and MoS2/BiPO4 nanorods

Herein, we report the enhanced solar light-mediated photocatalytic degradation of brilliant green dye using BiPO4 nanospindles and MoS2/BiPO4 nanorods synthesized by facile hydrothermal process. The synthesized nanomaterials were examined by various techniques such as X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy (TEM) attached with energy dispersive X-ray spectroscopy, Brunauer–Emmett–Teller, and pore size distribution analysis. The detailed characterizations revealed that after the introduction of MoS2, the crystalline phase transformation from hexagonal to monoclinic was observed for BiPO4. The TEM images clearly confirmed that BiPO4 possessed nanospindles and MoS2/BiPO4 exhibited nanorod-shaped morphologies. The photocatalytic activity of synthesized MoS2/BiPO4 nanorod heterojunction was explored for the degradation of brilliant green (BG) dye under solar light irradiation. Interestingly, approximate 80% degradation of BG was observed under solar light in 70 min using MoS2/BiPO4 nanorods as photocatalyst. As an efficient photocatalyst, the synthesized MoS2/BiPO4 nanorod heterojunction exhibited enhanced photocatalytic efficiency as compared to pure BiPO4 nanospindles, commercially available TiO2PC-50 and TiO2 PC-500 under solar light. The high photocatalytic activity of MoS2/BiPO4 nanorod heterojunction could be related to the amended visible light-harvesting tendency, effective charge separation, and facile transportation of photogenerated e−/h+ pairs at the heterojunction interface.

Visible light driven degradation of brilliant green dye using titanium based ternary metal oxide photocatalyst

We report a novel copper and cobalt impregnated titanium based ternary metal oxide nanocomposite (CuCO0.5Ti0.5O2) synthesized via simple chemical method. X-ray diffraction pattern and SAED pattern reveals the well crystallinity (R3̃m space group) and phase purity of the synthesized sample. TEM micrograph shows the nano size and heterostructure of the product. Nanoporous nature of the synthesized product is observed from BET analysis. The incorporation of the copper and cobalt in titanium oxide nanoparticle host modifies the band gap of the host and a broadband absorption spectrum (∼325 nm to 800 nm) of the nanocomposite is observed from the UV–Vis-NIR absorption spectroscopy analysis. Photoluminescence (PL) spectrum confirms generation of sufficient electron-hole pairs which could actively participate in photodegradation activity. Photocatalytic performance of the product has been investigated by degrading brilliant green (BG) dye, which shows excellent activity with increased catalytic material loading. The photocatalytic activity is enhanced at high pH level of the solution. Reusability experiments confirms that the catalyst material is reusable with almost same efficiency for degrading BG dye. Wavelength selective photocatalytic degradation of BG dye reveals that the CuCO0.5Ti0.5O2 nanocomposite shows the highest activity under blue-green illumination.

Influence of cation doping (Li+, Na+, K+) on photocatalytic activity of MIL-53(Fe)

The work highlights the influence of cation doping on photocatalytic activity of MIL-53(Fe) in artificial light. The effect of intrinsic factors, viz. band-gap energy, electron conductivity and surface area, influencing photocatalysis was studied in detail w.r.t. the degradation of brilliant green dye both in the presence and in the absence of H2O2 as an electron scavenger. Reduction in band gap after cation doping was observed for Li+ (1.81 eV), Na+ (1.875 eV) and K+ (1.89 eV) when compared with the parent MIL-53(Fe) (1.95 eV). However, the photoactivity of the synthesized materials was in the following progression: MIL-53(Fe)(81.6%) > Li-MIL-53(Fe)(27.6%) > Na-MIL-53(Fe)(25.77%) > K-MIL-53(Fe) (24.18%). Effect of structural distortions in the octahedral backbone of MIL-53(Fe) due to cation doping was inferred as the plausible reason behind such behavior. The degree of electron delocalization and specific surface areas were found to be in the following progression: Na-MIL-53(Fe) (very low, 7.72 m2 g−1) < K-MIL-53(Fe) (low, 28.38 m2 g−1) < Li-MIL-53(Fe) (moderate, 42.14 m2 g−1) < MIL-53(Fe) (high, 51.71 m2 g−1), indicating that the intrinsic material properties have combinatorial influence on photocatalytic activity.

Investigation of Photocatalytic Activity of Nd-Doped ZnO Nanoparticles Using Brilliant Green Dye: Synthesis and Characterization

An Nd doped ZnO (1-5%) photocatalyst was successfully synthesized via chemical co-precipitation method. The optical property, nature, and morphology of the synthesized nanoparticles were analyzed by UV-Visible, XRD, and FESEM respectively. XRD study reveals that Nd has been effectively incorporated in the ZnO lattice in the lower level dosage; however, the crystalline nature has been distorted towards the increase in the Nd. The selected brilliant green dye was degraded photo-catalytically with the help of the synthesized nanoparticles and the study has been extended with catalyst dosage and dye concentration. The 2% Nd-doped ZnO showed a remarkable result of 98.26% degradation of brilliant green dye compared to the other 1,3,4 & 5 % Nd-doped ZnO nanoparticles which clearly indicates the optimization of depletion region corresponding to the maximum degradation. The increased content (3-5%) of Nd-doped ZnO exhibited moderate photocatalytic degradation of the dye due to the decreased crystalline nature which was further evidenced from XRD studies.

Visible-light driven photocatalytic degradation of brilliant green dye based on cobalt tungstate (CoWO4) nanoparticles

Herein, we report the successful surfactant free synthesis, characterization and visible light driven photocatalytic application of highly crystalline cobalt tungstate (CoWO4) nanoparticles. The synthesized nanoparticles were characterized by several techniques which revealed that CoWO4 exhibited monoclinic phase of Wolframite structure, possess high crystallinity and grown in very high density. As the tungstate nanomaterials are hardly investigated as visible light responsive photocatalyst for the removal of organic pollutants in aqueous phase, thus, in this paper the photocatalytic efficiency of cobalt tungstate nanoparticles was estimated by monitoring the degradation of brilliant green dye under visible light irradiation. Approximately 94% brilliant green dye was degraded within 120 min of visible light illumination. Hydroxyl radicals were held to be accountable for the excellent photocatalytic performance. The present study offers an innovative approach stating that metal tungstates can also be considered as proficient visible light responsive photocatalysts for the degradation of hazardous organic contaminants from aqueous phase.