Maximum Degradation Percentage Research Articles

Fotokatalis Titanium Oksida (TiO2) Doping Tembaga (Cu) Menggunakan Metode Sol Gel untuk Fototransformasi Zat Warna Methylene Blue

Methylene blue is a heterocyclic synthetic dye used in the textile industry, but it has a negative impact on water quality and the surrounding environment. This research aims to degrade Methylene blue using a photocatalytic method. The catalyst used for degradation is TiO2 doped with 10% Cu. In this research, the degradation process uses 25 watt Uv light using a reactor. The degradation process was carried out by varying stirring at a speed of 1500 rpm and without stirring at 30, 60, 90 and 120 minutes. The degradation results were measured using a UV-Vis spectrophotometer to see the absorbance before and after degradation, and FTIR to see the shift in compound bonds. The results of this research showed that degradation using stirring had a higher percentage of degradation than without stirring. The maximum degradation percentage obtained in the research was 92.31% with a stirring speed of 1500 rpm for 120 minutes of exposure.

Eco-friendly synthesized manganese dioxide nanoparticles using Tridax procumbens as potent antimicrobial and dye degrading agent

Manganese dioxide nanoparticles (MnO2 NPs) were synthesized via a typical green synthesis method involving Tridax procumbens (TP) leaf extract extraction and utilization. The as-prepared material was further characterized using various physio-chemical methods to comprehend its structural, morphological, and optical properties. Powder X-ray diffraction (PXRD) reveals a tetragonal system with a space group of I 41/a m d, clearly indicating the presence of phytochemicals (impurity peaks at 25.46° and 54.92° diffraction angles). The calculated crystalline size of the sample was found to be 43 nm. Field Emission Scanning Electron Microscope (FESEM) results confirm the precursors of the as-prepared sample, also revealing the agglomerated structure. Furthermore, deeper morphology and crystallinity of the as-prepared MnO2 NPs have been studied through High-Resolution Transmission Electron Microscope (HR-TEM) images, which affirms the information about calculated d-spacing value (0.328 nm) and confirming crystallinity through Selected Area Electron Diffraction (SAED) image. Absorption studies were conducted on as-prepared samples, which show a characteristic band at 257 nm, affirming the formation of MnO2 NPs. The same was utilized to evaluate the band gap energy (4.46 eV) through the Kubelka-Munk function. To further confirm the calculated particle size and stability of the as-prepared MnO2 NPs, Dynamic Light Scattering (DLS) analysis was conducted, and the results revealed that the particles’ size was 58.72 nm. The prepared samples were subjected to study antimicrobial studies against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacterial species. The inhibition zone of the antibacterial disc soaked with as-prepared MnO2 NPs showed a significant increase compared to the TP leaf extract and commercially available MnO2 NPs. Also, the degradation of the Titan Yellow dye solution was conducted employing UV irradiation, and it was found that the maximum degradation percentage was attained after 120 min of irradiation. Furthermore, the pH effect on %degradation and reusability test were also conducted. The obtained results showed a pinnacle pH point of 4 where the degradation was maximum and found a decent decrement in %degradation after 4th usage. All the acquired results were utilized to study the degradation reaction kinetics, which was found that the present degradation holds good for both 0th and 1st order kinetic equations. Henceforth, the acquired results suggest that the green synthesized MnO2 NPs are potent candidates for antimicrobial and degrading activities.

Introduction of TbFeO3/TbCoO3 as a visible-active heterojunction nanocomposite: Facile synthesis and characterization with an environment-lover approach

A facile sol-gel method was used to synthesize an innovative nanocomposite containing Terbium orthoferrite (TbFeO3) and Terbium orthocobaltite (TbFeO3) with olive and Vitex agnus-castus leaves as natural reduction agents. The desired product comprised of two perovskites, TbFeO3 and TbCoO3, was utilized to degrade two anionic and cationic dyes after optimizing the synthesis conditions. A better photocatalytic efficiency in acidic media may be achieved as a result of the better performance of this nanocomposite for degradation of anionic dye. Also, the two other reactions were performed separately in order to synthesize each of the components of the as-synthesized nanocomposites. A couple of three-component nanocomposites with fascinating properties were produced as a result of this experiment. As a result of optical studies, different patterns of charge carrier transfer were assumed for them, which contributed to the theoretical creation of heterojunction photocatalysts with a variety of configurations. A summary of the results shows that the maximum degradation percentage of Eriochrom Black T during 90 min under visible light in pH = 5 in the presence of as-prepared was 91.7. This two-component nanocomposite demonstrated a type I configuration for charge carrier transfer.

Facile synthesis of Cu-doped BiVO4 using domestic microwave-assisted chemical precipitation method with fleeting time of microwave irradiation for the photocatalytic application

Semiconductor-based visible light active photo-catalyst has been synthesized through microwave-assisted chemical precipitation method under acidic pH with minimal time of reaction using microwave irradiation. The monoclinic crystal phase of the material with no impurity is confirmed with XRD data. We can observe slight left shift after doping with copper (Cu) in 2Θ peak of XRD data. SEM analysis exhibits a gradual change in morphology with the increase in doping concentration. UV–Vis data confirms an improvement in absorption with the increase in dopant concentration. PL analysis further clarifies the change in recombination rate of photo-induced charge carriers. Photocatalysis has been tested with methylene blue (MB) synthetic dye. The maximum percentage of degradation was determined to be 61.08% and it is obtained for 0.25% Cu-doped BiVO4. It is also observed that 0.25% Cu-doped BiVO4 has lower energy band gap value, i.e., 2.03 eV and lesser PL intensity than pure un-doped BiVO4. The HRTEM analysis proves that 0.25% Cu-BiVO4 is well crystalline in nature with the d spacing corresponding to (121) plane of BiVO4.

Effect of Molarity on Double Layer Photocatalytic Activity ZnO/ZnO:Ag for Metanil Yellow Degradation

Double layer (DL) ZnO/ZnO:Ag has been synthesized with variations in molarity of 0.1, 0.3, 0.5, and 0.7 M and its application as a degrading agent for methanil yellow dye. This study aims to determine the effect of the molarity of the DL ZnO/ZnO:Ag on crystallinity and photocatalytic activity for methanil yellow degradation. DL ZnO/ZnO:Ag was synthesized using sol-gel technique and deposited with spray coating technique. The results of DL ZnO/ZnO:Ag were characterized by XRD to determine the crystallinity and particle size. The photocatalytic activity was carried out by immersing the DL ZnO/ZnO:Ag layer in 10 ppm methanil yellow solution and irradiating it with UV light for 4 hours and then tested using UV-Vis spectroscopy to get the percentage of methanil yellow degradation. The results showed that the crystallinity of the DL ZnO/ZnO:Ag for all molarity variations had a hexagonal wurtzite structure. Grains size increase as molarity increases from 0.1 to 0.5 M. However, if the concentration continues to be increased to 0.7M, the grain size decreases. Photocatalytic activity is increasing every hour, as indicated by the increasing percentage of degradation. Precursor in 0.5 M has the maximum percentage of degradation is 25.32%.

Visible-light-driven photodegradation of xanthate in a continuous fixed-bed photoreactor: Experimental study and modeling

Photocatalysis has been widely employed as a promising method for wastewater treatment. However, existing studies are primarily conducted in batch reactors. To the best of our knowledge, a continuous reactor has not been used to degrade xanthate residual in mineral beneficiation wastewater. In this work, a continuous fixed-bed photoreactor (CFPR) was first designed, and Bi2WO6 photocatalysts coated on silica sands were used to degrade sodium isobutyl xanthate (SIBX) under visible light irradiation. The effects of various parameters, including catalyst loading, pH level, initial SIBX concentration, wastewater flow rate, calcium ion (Ca2+) concentration, magnesium ion (Mg2+) concentration, and zinc ions (Zn2+), on the degradation efficiency, were systematically investigated. The results show that the photodegradation percentage of SIBX increases with increasing catalyst loading, decreasing initial concentration, and decreasing flow rate within the scope under investigation. Additionally, low concentrations (30 mg·L−1) of Ca2+ and Mg2+ ions favor the photodegradation of SIBX, whereas excessive Ca2+ and Mg2+ ions (240 mg·L−1) inhibit photocatalytic activity. The presence of Zn2+ ions inhibits photodegradation percentage. Furthermore, the photodegradation percentage is slightly higher at alkaline than at acidic pH. The maximum degradation percentage reached 95.40 % after 70 min of visible light irradiation under optimal conditions. In addition, a fixed bed reactor model considering surface reaction kinetics and mass transfer constraints was established by combining the Langmuir-Hinshelwood (L-H) kinetic equations and the series resistance theory. This model can accurately estimate the intrinsic kinetic parameters and can well predict degradation efficiency with a root-mean-square-error (RMSE) of 4.24 %. Finally, the bottleneck for improving the performance of the reactor can be identified under different conditions.

Photodegradation of sodium dodecyl sulfate and sodium dodecylbenzene sulfonate with hydrothermally synthesized PbTiO3 catalyst

Synthesis of PbTiO3 as a photocatalyst for degradation of sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (SDBS) has been carried out. Catalyst PbTiO3 has been synthesized by hydrothermal method at temperature 220 °C for 30 min. Synthesis of PbTiO3 was prepared with composition variation of TiO2:PbO (w/w) at (1:3), (1:2), (1:1), (2:1), (3:1), and pH at 3, 5, 7, 9, 11. The PbTiO3 was characterized by XRD, FTIR, DR-UV, and SEM-EDX. Photodegradation performance was analyzed with visible light sources for 30 min and calculated using Spectrophotometer Uv–Vis. PbTiO3 at ratio TiO2:PbO 1:2 (w/w) has the maximum degradation percentage of SDS (70.42%) and SDBS (84.84%). The optimum pH to perform photodegradation was pH = 5 with degradation efficiency of SDS and SDBS were 85.69% and 85.56%.

Enhanced Photocatalytic Degradation of <i>p</i>-Nitrophenol and Phenol Red Through Synergistic Effects of a CeO<sub>2</sub>-TiO<sub>2</sub> Nanocomposite

Organic compounds are one of the most severe pollutants occurring in the environment. Hence, it is important to remove these compounds from the environment through remediation processes such as photocatalysis. The present study investigated the photocatalytic degradation of <em>p</em>-nitrophenol (NP) and phenol red (PR) using a cerium oxide-titanium oxide nanocomposite (CeO<sub>2</sub>-TiO<sub>2</sub>nc) under UV light. CeO<sub>2</sub>-TiO<sub>2</sub>nc was synthesized using the co-precipitation method. An X-ray diffraction (XRD) analysis confirmed the phase purity of the material. A UV-Vis absorption study revealed a broad peak in the 250–310 nm region. The photocatalytic study was performed under three irradiation conditions: no light, visible light (λ > 400 nm), and UV light (λ < 400 nm). The maximum degradation percentage for NP and PR was 97.3% and 99.8%, respectively, with the reaction rate constant (k) of 0.42 and 0.54, respectively. This is the first study to utilize the synergistic effects of TiO<sub>2</sub> and CeO<sub>2</sub> for degrading NP and PR. Over 97% degradation was achieved for both the compounds in 80 min; this result shows the high photocatalytic activity of CeO<sub>2</sub>-TiO<sub>2</sub>nc<sub>.</sub> Thus, CeO<sub>2</sub>-TiO<sub>2</sub>nc<sub> </sub>can be used as a cost-effective adsorbent with a high capacity to degrade harmful organic compounds.

Facile bio-fabrication of ZnO@AC nanoparticles from chitosan: Characterization, hydrogen generation, and photocatalytic properties

In this work, activated carbon-supported zinc oxide nanoparticles (ZnO@AC NPs) were studied using the thermal synthesis method. The activated carbon-supported zinc oxide catalyst was characterized by UV–Vis spectrometry techniques, Fourier Transform Infrared Spectrophotometer (FTIR), Transmissive electron microscopy (TEM), and X-ray diffraction (XRD) methods. XRD characterization measurements showed that the average size of the crystal NPs was 6.89 nm. According to the TEM analysis results, the nanoparticles' average size was 11.411 nm, and the particles had a spherical structure. The catalytic properties of the synthesized material were determined using the sodium borohydride methanolysis reaction. A kinetic study was performed regarding the effects of temperature, catalyst, and substrate concentration on the methanolysis reaction. Reusability experiments showed that the catalyst had excellent catalytic activity (85%), stability, and selectivity. As a result of the kinetic study, activation energy, enthalpy (ΔH), entropy (ΔS), and hydrogen production rate activation parameters were found to be 42.52 kJ/mol, 39.98 kJ/mol, −181.42 J/mol.K, 1257.69 mL/min. g, respectively. Also, the photocatalytic activity of ZnO@AC NPs was analyzed against Rhodamine B (RhB) dye, and the maximum degradation percentage was observed to be 76% at 120 min. This study aimed to develop the ZnO@AC NPs into an efficient photocatalyst to prevent industrial wastewater pollution and as a catalyst for hydrogen synthesis as an alternative energy source.

Effective treatment of high-concentration SDBS solution by developing a novel integrated technology of foam separation and photocatalysis

With the rapid increasing drainage of industrial sewage, the problems arising from sewage containing high-concentration surfactant become more urgent. In order to purify the high-concentration surfactant solution, a novel integrated technology of foam separation and TiO2 photocatalysis was developed. An anionic surfactant of sodium dodecyl benzene sulfonate (SDBS) was used as the model surfactant and its initial concentration in the simulated solution was 0.5 g/L. First, foam separation had been performed to primitively reduce SDBS concentration in the simulated solution. Based on the results of independent factor test, a five-level-three-factor central composite design (CCD) based on response surface design (RSM) was used to predict the optimal experimental conditions. Under above conditions, the enriching proportion and removing percentage of SDBS were 4.69 ± 0.14 and 84.85 ± 0.71 %, respectively. The surface tension and foam stability of the residual solution after foam separation had been measured using pulling ring method and bubbling method, respectively. The residual solution after foam separation possessed a higher surface tension and weaker foam stability compared with those of freshly prepared SDBS solution. Extrinsic fluorescence spectra using pyrene showed that interfacial adsorption had led to the generation of hydrophilic SDBS micelles. In order to perform TiO2 photocatalysis, the adsorption capacity of SDBS on TiO2 nanoparticles had been studied. The adsorption of SDBS on TiO2 nanoparticles obeyed Pseudo-second-order dynamics model and Freundlich isotherm model. Based on the unique optical property and particle entrainment capacity of foam, a coupling operation of foam separation and TiO2 photocatalysis was proposed to degrade SDBS in the residual solution. The suitable operating conditions were identified and the maximum degradation percentage of SDBS reached 94.86 ± 1.06 %. The total SDBS removing percentage of developed technology was 99.38 ± 0.10 %. Total organic carbon (TOC) concentrations of SDBS solution before and after treatment were measured using combustion oxidation coupled nondispersive infrared absorption method. Finally, the economic analysis was carried out to assess the cost effectiveness of the integrated technology of foam separation and TiO2 photocatalysis.

Visible light assisted heterojunction composite of AgI and CDs doped ZIF-8 metal-organic framework for photocatalytic degradation of organic dye

• CDs@ZIF-8@AgI was prepared by a solvent-free way coupled to ion deposition strategy. • Acridine Orange can be effectively degraded by CDs@ZIF-8@AgI under visible light. Water pollution induced by the productive process of organic dyes would lead to various diseases, and so treatment of the wastewater is an urgent task for protecting human health and ecological environment. In this work, visible light responsive heterojunction material based on silver iodide and carbon dots (CDs) doped ZIF-8 metal organic frameworks (CDs@ZIF-8@AgI) has been prepared by a green solvent-free strategy and in-situ ion deposition method. The CDs@ZIF-8@AgI composites have high photocatalytic performance for degradation of acridine orange (AO) dye under visible light, and the maximum degradation percentage can reach to 96.0%, which was estimated by the UV-visible spectroscopy. The porous structure and large surface area of the photocatalyst were favorable to absorption of the target dye on the catalyst, which can promote the kinetic degradation rate for low level concentration of the dye. The introduction of CDs into the AgI heterojunction can improve the electron transport efficiency and visible light absorption capacity, and thus significantly enhancing the photocatalytic activity of the catalyst. The photocatalytic mechanism was proposed as indirect Z-scheme heterojunction type based on the energy band structure of the catalyst. This work provides a visible light photocatalyst for removal of the AO dye in wastewater and offers a promising strategy for developing photocatalyst for treatment of organic pollutants in the environment using solar energy.

Ce3+/Ce4+-Doped ZrO2/CuO Nanocomposite for Enhanced Photocatalytic Degradation of Methylene Blue under Visible Light.

In recent years, photocatalysis has been used as an environmentally friendly method for the degradation of organic pigments in water. In this study, Ce3+/Ce4+-doped ZrO2/CuO as a mixed semiconductor oxide was successfully prepared by a one-step hydrothermal method. The Ce3+/Ce4+-doped ZrO2/CuO has shown high degradation efficiency of methylene blue (MB), and the maximum degradation percentage was observed to be 94.5% at 180 min under irradiation visible light. The photocatalytic activity increases significantly by doping Ce3+/Ce4+ in ZrO2/CuO for MB degradation. Ce3+/Ce4+ doping is shown to reduce the (e-/h+) recombination rate and improve the charge transfer, leading to enhanced photocatalytic activity of materials. The materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), FTIR, EDS, BET and diffuse reflectance spectroscopy (DRS).

Activation of peroxydisulfate via photothermal synergistic strategy for wastewater treatment: Efficiency and mechanism

Peroxydisulfate (PDS)-based advanced oxidation processes (AOPs) have been demonstrated to be an effective technology for the removal of refractory organic contaminants from the aquatic environment. Herein, a photothermal synergistic strategy is developed to realize the green activation of PDS under solar light irradiation. An innovative solar photothermal reaction system and its corresponding evaluation method are established. The results show that there is a synergistic effect between light and light-generated thermal effects on the activation of PDS for effectively removing fulvic acid (FA). The maximum degradation percentage of FA increases from 42.6% to 90.8% after introducing ZrC nanoparticles as photothermal materials. The maximum temperature of the whole system is up to 66.4 ℃ after 120 min irradiation at 0.007 wt% solid content of ZrC, which is higher by 26.9% compared with that in the absence of ZrC nanoparticles. Furthermore, the underlying mechanism and PDS activation efficiency are deeply investigated. This work provides a viable strategy for directly using solar radiation to activate PDS for degrading refractory organic compounds, which creates a new avenue toward the utilization of solar energy for wastewater treatment.

An environmental approach for the photodegradation of toxic pollutants from wastewater using Pt–Pd nanoparticles: Antioxidant, antibacterial and lipid peroxidation inhibition applications

BackgroundGreen synthesis is an effective and friendly method for the environment, especially in recent years has been used in many areas. It finds application opportunities in many fields such as physics, chemistry, electronics, food, and especially health and is the subject of intensive studies in this field. ObjectivesThe synthesized Pt–Pd NPs were aimed to be used as a bio-based photocatalyst under sunlight to prevent wastewater pollution. In addition, it is aimed to use Pt–Pd NPs as biological agents in different applications in the future. MethodsIn this study, the platinum-palladium nanoparticles were synthesized by the extract of Hibiscus sabdariffa, the characterization of the nanoparticles was carried out by different methods (ultraviolet–visible spectroscopy (UV–vis), transmission electron microscopy (TEM), infrared transform spectroscopy atomic force microscopy (AFM), and ray diffraction (XRD) analysis). And we discussed several different parameters related to human health by obtaining platinum-palladium bimetallic nanoparticles (Pt–Pd NPs) with a green synthesis method. These parameters are antioxidant properties (total phenolic, flavonoid, and DPPH scavenging activity), antibacterial activity, and lipid peroxidation inhibition activity. Gallic acid was used as standard phenolic, and quercetin was used as standard flavonoid reagents. The newly synthesized Hibiscus sabdariffa mediated green synthesized Pt–Pd NPs were compared with gram-positive and gram-negative bacteria, the high antibacterial activity was shown by gram-positive bacteria. The photodegradation of Pt–Pd NPs was carried out against MB dye for 180 min. ResultsTEM results show that the average size of Pt–Pd NPs is around 4.40 nm. The total amount of phenolic compounds contained in 0.2 mg/ml of Pt-Pd NPs was equivalent to 14.962 ± 7.890 μg/ml gallic acid and the total amount of flavonoid component was found to be equal to 28.9986 ± 0.204 μg/ml quercetin. Hibiscus sabdariffa mediated green synthesized Pt–Pd NPs was found to have very effective for lipid peroxidation inhibition activity in the FeCl2–H2O2 system. The maximum DPPH scavenging activity was determined as 97.35% at 200 μg/ml. The photocatalytic activity of Pt–Pd NPs was analysed against Methylene blue (MB) and the maximum degradation percentage was observed to be 83.46% at 180 min. ConclusionsThe biogenic Pt–Pd NPs showed a high effective photocatalytic and biological activity.

OPTIMIZATION OF MEDIA COMPONENTS AND PROCESS PARAMETERS FOR MICROBIAL MEDIATED REMEDIATION OF AZO DYES: A REVIEW

Azo dyes are one of the most commonly used synthetic dyes with enormous applications in the textile industry. The recalcitrant properties of azo dyes could be attributed to the highly complex chemical organization. The limitations such as high cost and emergence of secondary toxic pollutants as by-products associated with physicochemical mode of degradation urged researchers to explore potential alternatives. Microorganisms having versatile metabolic pathways and adaptations to different environmental conditions gained the attention of researchers to exploit them for azo dyes degradation in a cost-effective manner. The azo dye degradation using microbial sources proved to be a promising approach as compared to conventional physicochemical approaches. Microorganisms can induce different metabolic pathways in response to the external environment. The biodegradation efficacy of the microorganisms-based approach can be maximized by optimizing the culture media and process parameters. Optimization techniques predict the conditions required to increase the efficacy of azo dyes degradation by microbial sources and also decrease the number of experimental runs to achieve the maximum percentage of degradation. Interaction of variables such as medium components and process parameters can be determined using optimization tools. Response Surface Methodology (RSM) and Artificial Neural Network (ANN) based optimization approaches were discussed in this review with special emphasis on microbial degradation of azo dyes.

Pyrene degradation in an aqueous system using ferrous citrate complex activated persulfate over a wide pH range

To explore an effective liquid material for the degradation of polycyclic aromatic hydrocarbons (PAHs), sodium citrate (SC) was selected from four kinds of chelating agents for persulfate (PS) activation by transition metals to degrade pyrene in an aqueous system. PS activated by SC chelated ferrous ion (PS/Fe2+/SC) can catalyze pyrene degradation under neutral pH, and when the molar ratio of PS, SC, Fe2+ and pyrene was 2000/2000/2000/1, the maximum degradation percentage reached 94.4% in 720 min through enhancing the PS consumption and oxidative capacity of the system. Furthermore, the pyrene degradation catalyzed by PS/Fe2+/SC was not influenced by pH in the range from 3.0 to 11.0, PS/Fe2+/SC system could effectively catalyze the pyrene degradation over a wide pH range. Additionally, the presence of 0.1 M of SO42- and H2PO4- decreased the pyrene degradation using the PS/Fe2+/SC system, while 0.1 M of Cl- and NO3- had little effect on the pyrene degradation when PS/Fe2+/SC was used under neutral pH. Furthermore, pyrene degradation was attributed to the sulfate and hydroxyl radicals produced from PS/Fe2+/SC system, and these radicals were detected with strong signals of DMPO-SO4 and DMPO-OH through electron paramagnetic resonance (EPR) spectroscopy. Finally, seven pyrene degradation products were identified by gas chromatography-mass spectrometer (GC-MS), and a possible pathway of pyrene degradation was proposed.

Phyto-Extract-Mediated Synthesis of Silver Nanoparticles Using Aqueous Extract of Sanvitalia procumbens, and Characterization, Optimization and Photocatalytic Degradation of Azo Dyes Orange G and Direct Blue-15.

Green synthesis of silver nanoparticles (AgNPs) employing an aqueous plant extract has emerged as a viable eco-friendly method. The aim of the study was to synthesize AgNPs by using plant extract of Sanvitalia procumbens (creeping zinnia) in which the phytochemicals present in plant extract act as a stabilizing and reducing agent. For the stability of the synthesized AgNPs, different parameters like AgNO3 concentration, volume ratios of AgNO3, temperature, pH, and contact time were studied. Further, AgNPs were characterized by UV–visible spectroscopy, FT-IR (Fourier Transform Infrared Spectroscopy), XRD (X-ray Diffraction), SEM (Scanning Electron Microscopy), and EDX (Energy Dispersive X-ray Spectrometer) analysis. FT-IR analysis showed that the plant extract contained essential functional groups like O–H stretching of carboxylic acid, N–H stretching of secondary amides, and C–N stretching of aromatic amines, and C–O indicates the vibration of alcohol, ester, and carboxylic acid that facilitated in the green synthesis of AgNPs. The crystalline nature of synthesized AgNPs was confirmed by XRD, while the elemental composition of AgNPs was detected by energy dispersive X-ray analysis (EDX). SEM studies showed the mean particle diameter of silver nanoparticles. The synthesized AgNPs were used for photocatalytic degradation of Orange G and Direct blue-15 (OG and DB-15), which were analyzed by UV-visible spectroscopy. Maximum degradation percentage of OG and DB-15 azo dyes was observed, without any significant silver leaching, thereby signifying notable photocatalytic properties of AgNPs.

The Utilization of Modified Chitosan from Shrimp Shell As Photodegradation of Pesticides Paraquat Dichloride

In this study, the chitosan modification of shrimp shell has been made by impregnated the chitosan from shrimp shell with Ti/ZrO2 and ZrO2 to formed composite of chitosan-Ti/ZrO2 and chitosan-ZrO2. These composites were made by immobilization technique and characterized by FTIR and SEM-EDX. The chitosan-Ti/ZrO2 and chitosan-ZrO2 composite were used as a catalyst to degrade the pesticide paraquat dichloride in the presence of UV light (????= 257 nm). The photodegradation process of paraquat dichloride takes place under 10 watts UV light irradiation and was measured using spectrophotometer UV. The maximum degradation percentage of pesticide paraquat dichloride photodegradation by chitosan-Ti/ZrO2 and chitosan-ZrO2 composites are 61.97% and 57.97% within 30 minutes irradiation time.

Photocatalytic degradation of hydroxychloroquine using ZnO supported on clinoptilolite zeolite.

The objective of this work was to evaluate the photocatalytic activity of zinc oxide catalysts supported on natural zeolite clinoptilolite for photocatalytic degradation of the drug hydroxychloroquine, used in the treatment of malaria and which has been tested in the treatment of COVID-19. To synthesize 10%ZnOCP and 15%ZnOCP catalysts, the wet impregnation methodology was used. The raw and synthesized catalysts were characterized by XRD, SEM, XRF, BET, DRS, PCZ, FT-IR and PL. The degradation of hydroxychloroquine was calculated using UV-vis absorption from the samples before and after the photocatalytic process. The maximum percentage of degradation (96%) was obtained with the operational parameters of C0 = 10 mg L-1; Ccat = 2 g L-1 of 15%ZnOCP; pH = 7.5; UV-A radiation. Ecotoxicological tests against the bioindicators Lactuca sativa and Artemia salina confirmed the reduction of effluent toxicity after treatment.

Sm-substituted copper-cobalt ferrite nanoparticles: Preparation and assessment of structural, magnetic and photocatalytic properties for wastewater treatment applications

The nanoparticles of Co0.5Cu0.5SmxFe2−xO4 (0 ≤x ≤ 0.15) (CCS) were synthesized with the citrate combustion approach and then exploited to remove the noxious Rhodamine B (RhB) dye from the pollutant water. Before this mission of RhB disposal began, the CCS ferrite nanoparticles were comprehensively characterized by progressing analysis; as XRD, FTIR, STEM, VSM, DRS. The average crystallite size estimated using Williamson-Hall (W–H) method is in the range (75–45 nm). FTIR spectra exhibits the two finger print bands υ1 (~572) and υ2 (~375) of spinel ferrites. The STEM-EDX micrographs confirmed the purity, nanocrystalline nature of the CCS samples and existence of all the constituents' elements; Co, Cu, Sm, Fe and O ions without any other impurities. A gradual decrease for Ms values is remarked with further Sm3+ ions substitution; from MS= 55.373 emu/g (at x = 0.0) to MS= 43.981 emu/g (at x = 0.15). Coercivity shows a distinct behavior; increased from 892.81 Oe at pristine Co–Cu sample reaching a maximum value 1112.70 Oe (at x = 0.09) and then decreased to 983.09 Oe (for x = 0.15). The microwave frequency of the CCS nanoferrites is in the range 12.25–9.73 GHz. The pristine Co–Cu nanoparticles has band gap 1.57 eV, whereas all Sm3+ substituted nanoferrites have lower band gap values as 1.51, 1.55, 1.44, 1.51 and 1.36 eV with further Sm3+ ion substitution process. The photocatalytic activity of the nano-Co0.5Cu0.5SmxFe2−xO4 catalysts were scrutinized by the degradation of RhB dye using simulated sunlight source. Astonishingly, maximum degradation percentage was aggrandized to be 94.36%, under 270 min, for the nanoferrite with x = 0.15. Therefore, it is concluded that Sm doped Co–Cu nanoferrites is more convenient candidate for wastewater treatment applications besides switching, and high frequency absorption applications in microwave region.