Degradation Of Indigo Carmine Research Articles

Comparative study of photo catalytic activity of Tinospora Cordifolia derived nanoparticles for degradation of indigo carmine

Plant-mediated synthesis of nanoparticles has emerged as an important field in synthesis of nanoparticles (NPs) as fewer chemicals are being used, method is cost-effective and also fulfils principles of green chemistry. Due to the rapid growth of industries in recent times, there has been an increase in concentration of dyes in water, which causes problems and affects human and animal’s health. Moreover, nanoparticles has emerged as an effective solution for dye degradation due to their effective catalytic activity. In the current work, we carried out a comparative study on Tinospora Cordifolia, derived oxide nanoparticles for degrading Indigo Carmine. The characterization of formed particles have been done by techniques like XRD, SEM, FTIR and EDX. The effectiveness of the synthesized nanoparticles as photo catalyst in removing indigo carmine was assessed by emphasizing on important aspects such as amount of catalyst, concentration of dye, and the pH. The results showed SnO2 nanoparticles exhibited superior degrading activity compared to CuO. The optimal dose for SnO2 NPs was 0.25 g/L, while for CuO, it was 0.50 g/L. When pH was altered, it was observed that acidic environment exhibited superior breakdown ability. The optimal degradation capability was observed at dye concentration of 40 parts per million (ppm).

Fungi from Antarctic marine sediment: characterization and assessment for textile dye decolorization and detoxification.

Cold-adapted microorganisms can produce enzymes with activity at low and mild temperatures, which can be applied to environmental biotechnology. This study aimed to characterize 20 Antarctic fungi to identify their genus (ITS rDNA marker) and growth temperatures and evaluate their ability to decolorize and detoxify the textile dye indigo carmine (IC). An individual screening was performed to assess the decolorization and detoxification of IC by the isolates, as well as in consortia with other fungi. The isolates were affiliated with seven ascomycete genera: Aspergillus (n = 4), Cosmospora (n = 2), Leuconeurospora (n = 2), Penicillium (n = 3), Pseudogymnoascus (n = 6), Thelebolus (n = 2), and Trichoderma (n = 1). The two isolates from the genus Leuconeurospora were characterized as psychrophilic, while the others were psychrotolerant. The Penicillium isolates were able to decolorize between 60 and 82% of IC. The isolates identified as Pseudogymnoascus showed the best detoxification capacity, with results varying from 49 to 74%. The consortium using only Antarctic ascomycetes (C1) showed 45% of decolorization, while the consortia with the addition of basidiomycetes (C1 + Peniophora and C1 + Pholiota) showed 40% and 50%, respectively. The consortia C1 with the addition of the basidiomycetes presented a lower toxicity after the treatments. In addition, a higher fungal biomass was produced in the presence of dye when compared with the experiment without the dye, which can be indicative of dye metabolization. The results highlight the potential of marine-derived Antarctic fungi in the process of textile dye degradation. The findings encourage further studies to elucidate the degradation and detoxification pathways of the dye IC by these fungal isolates.

Enhancement of visible-light photocatalysis of TiO2 via nanocomposite incorporating with Fe(III) species

This paper introduces a novel approach for the synthesis of photocatalytic nanocomposites via a fast reaction occurring at ambient conditions between the strong base NaOH and FeCl3 solution to obtain a fresh precipitate of Fe(OH)3 in the presence of TiO2 nanoparticles. FE-SEM analysis revealed a restructured state of TiO2 particles on the surface of colloidal Fe(OH)3. Solid-phase studies, including XRD and FT-IR, indicated a phase transformation from Fe(OH)3 to γ-Fe2O3 during the formation of the nanocomposite. UV–Vis diffuse reflectance measurements confirmed a significant reduction in the band gap of the synthesized composite, indicating its potentials as a photocatalyst under visible light irradiation. Another advantage of this composite type is its rapid sedimentation ability within minutes, facilitating post-processes such as phase separation and catalyst reuse on a large scale, which are challenging in the case of TiO2 nanoparticles. Inducing photocatalysis under visible light, the efficiency in degrading persistent colorants was demonstrated through a case study of indigo carmine (IC), which exhibited a threefold improvement in degradation efficiency for the case of the nanocomposite compared to the original TiO2. Indeed, the IC degradation process was studied in consideration of various factors such as Fe/Ti ratio in the catalyst, illumination time, colorant concentration, catalyst dosage, and pH of the environment. Additionally, mineralization studies confirmed the oxidation of IC to CO2 rather than the formation of potentially toxic intermediates. Furthermore, the stability of the catalyst was examined through six cycles of reuse.

Carbon-dot/attapulgite composite sonocatalytic towards efficient indigo-containing wastewater degradation based on the cavitation mechanism

Catalytic degradation is an effective method to treat indigo carmine (IC) in wastewater, while high-performance catalyst materials need to be explored. Herein, a facile “spot-heating” synthesis method was employed, whereby the carbon dots (CDs) sonosensitizer was loaded onto the surface of attapulgite (ATP) with ultrasonic cavitation effect, resulting in a composite sonosensitizer ec-CDs/ATP (where ec-CDs represent CDs prepared from ethanol (e) and citric acid (c)). ATP served as a good carrier promotes uniform dispersion of CDs. Benefiting from the large specific surface area, more active sites on the surface of ec-CDs/ATP were exposed, which promotes efficient degradation performance for IC, with a 20 % improvement in performance compared to the reported pure CDs or composite CDs photocatalysts (Bi2O3/dots, Cl-dots). The selective deactivation reactions and relative characterizations further verify that the catalytic process is compatible with the sonocatalytic mechanism originating from the fracture of surface oxygen-containing groups. Importantly, ec-CDs/ATP with a small mass of CDs loading achieves the same catalytic performance as a large mass of pure CDs. This research innovatively presents a simple synthesis method of a composite CDs sonosensitizer and explores its mechanism of degradation, thus pointing the way to the design of multifunctional sonocatalysts for the degradation of IC in wastewater.

Construction of coordination polymer [Ni(ppda) (tib) (H2O)]·H2O and photocatalytic degradation of indigo carmine

Semiconductor coordination polymers have garnered significant attention as photocatalysts for wastewater treatment owing to their adaptable structure, expansive specific surface area, and outstanding selectivity, stability, and sensitivity. In this study, coordination polymer [Ni(ppda) (tib) (H2O)]·H2O was synthesized utilizing flexible phenyldiacetic acid (H2ppda) and rigid 1,3,5-tris(1-imidazolyl)benzene (tib). Crystal structure analysis revealed that the three-linked tib ligands and the central Ni(II) ion create a wavy 2D surface. Additionally, cis-ppda2- ligands form a 1D wave chain alongside central Ni(II), which traverse through a 2D layer. Adjacent layers are interlaced via ppda2−, resulting in a complex 3D supramolecular structure. The fundamental framework of [Ni(ppda) (tib) (H2O)]·H2O exhibits stability up to 316 °C and remains stable over 5 cycles, with a band gap energy of 2.9 eV, rendering it a viable candidate for catalytic applications. In aqueous systems, [Ni(ppda) (tib) (H2O)]·H2O demonstrates efficient photocatalytic degradation of Indigo Carmine (IC), achieving a degradation rate of 98.5% and a reaction rate of 0.027 min−1, showcasing commendable selectivity and semiconductor properties. The primary photocatalytic degradation mechanism involves the synergistic formation of ·OH and ·O2- active species through the interaction between [Ni(ppda) (tib) (H2O)]·H2O and H2O2, facilitating the oxidative degradation of dye molecules.

Effectiveness of Ag@NiO@g-C3N4 photocatalysts: Green fabrication and superior photocatalysis capability

A novel nanocomposite material, Ag@NiO@g-C3N4, was synthesized using ultrasonic irradiation with Ag@NiO as precursor materials. X-ray diffraction (XRD) analysis confirmed the formation of g-C3N4 and anatase Ag@NiO phases within the nanocomposite. Transmission electron microscopy (TEM) imaging revealed the deposition of Ag@NiO nanoparticles onto g-C3N4 layers. X-ray photoelectron spectroscopy (XPS) verified the presence of C, N, O, Ni, and Ag in the nanocomposite. The synthesized nanocomposite exhibited a significantly increased surface area of 94.705 m2/g and a reduced energy band gap of 3.07 eV. The photocatalytic activity of NiO nanoparticles, Ag@NiO nanoparticles, g-C3N4 nanosheets, and the Ag@NiO@g-C3N4 nanocomposite was evaluated under visible light irradiation. The Ag@NiO@g-C3N4 nanocomposite demonstrated superior photocatalytic performance compared to the individual components. The photocatalytic degradation of indigo carmine (IC) dye was used to assess the photocatalytic activity, and the Ag@NiO@g-C3N4 nanocomposite exhibited exceptional efficacy exhibited a significantly higher reaction rate, estimated to be approximately 100 times faster than the unmodified process. This observation implies that the Ag@NiO@g-C3N4 nanocomposite exhibits potential as a viable material for various environmental applications.

Synthesis and characterization of bi-functional Cu and Ni co-doped ZnO photocatalysts for organic pollutant degradation and antimicrobial activity

The study of visible light active photocatalysts for organic pollutants degradation and antimicrobial activity has gained significant attention in recent years. Herein, we report the synthesis of pure ZnO, Ni-doped ZnO (Ni-ZnO), Cu-doped ZnO (Cu-ZnO), and Cu and Ni co-doped ZnO (CuNi-ZnO) photocatalysts via a facile coprecipitation method. These photocatalyst materials were characterized using various analytical techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscope (HR-TEM), Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy (UV–Vis), photoluminescence (PL), and total organic carbon (TOC) analysis. XRD patterns confirm the presence of a mixed phase in the CuNi-ZnO sample. The presence of Cu, Ni, and Zn in CuNi-ZnO was verified through the XPS spectra. The nanoparticle-like morphology of the CuNi-ZnO photocatalyst was confirmed using HRTEM analysis. The FTIR spectra reveal the chemical bonds present in the materials. UV–visible spectroscopy was employed to determine the band gap of the materials, revealing a value of 3.10 eV for CuNi-ZnO. The mitigation in recombination of excited electrons (e−) and holes (h+) in CuNi-ZnO is validated through photoluminescence (PL) studies. The synthesized materials were used for the degradation of Indigo carmine (IC) dye and antimicrobial activity. The results showed that the optimized CuNi-ZnO sample displayed a better visible light photocatalytic performance (93.32 % IC dye degradation efficiency in 60 min) than the other samples. A notable degree of mineralization was observed with a reduction in total organic carbon (TOC) reaching 65.91 %. Additionally, the photocatalyst showed antimicrobial activity against both S. aureus and E. coli. Furthermore, a plausible visible light photocatalytic mechanism was proposed for the degradation of IC dye using the CuNi-ZnO photocatalyst.

Simultaneous degradation of methyl orange and indigo carmine dyes from an aqueous solution using nanostructured WO3 and CuO supported on Zeolite 4A

In this study, a novel composite catalyst system, Zeolite 4A/WO3/CuO with a Z-scheme design, was synthesized for photocatalysis, sonocatalysis, and sono-photocatalysis methyl orange (MO) and indigo carmine (IC) dyes simultaneously. The properties of the Zeolite 4A/WO3/CuO composite were thoroughly investigated using various techniques, and the results confirmed the synthesis of the desired catalyst system. In the sono-photocatalytic process, using the Zeolite 4A/WO3/CuO composite, the maximum efficiency for MO (99.12 %) and IC (97.24 %) was achieved at pH of 2 and 3, with a catalyst dosage of 0.15 g/L, a dye concentration of 10 mg/L, a contact time of 25 min, and H2O2 dosage of 30 µL/100 mL. The dye elimination efficiency using the sono-photocatalytic process was reduced in the presence of Cl- and PO43- in the distilled water. The efficiency also declined in the medium of river and well water resources. Moreover, the Zeolite 4A/WO3/CuO catalyst maintained over 90 % of its performance even after five reuse cycles. Based on the kinetic study, the sono-photocatalytic process exhibited higher activation for the removal of MO (k: 0.1946 min−1 and t1/2: 3.561) and IC (k: 0.1433 min−1 and t1/2: 4.836) than other processes. The synergy values for the MO and IC degradation using the Zeolite 4A/WO3/CuO composite were determined to be 2.167 and 2.303, respectively. The impact of various scavengers demonstrated that in the degradation processes of the target dyes using the sono-photocatalytic process, different active species like OH•, e-, h+, and O2–• are involved. The purification of dye-laden water using the sono-photocatalytic process was not toxic for plant germination, microorganisms, and fish, highlighting the successful biocompatibility of the process for dye removal.

Box–Behnken Design and experimental studies on novel fibrous g-C3N4 towards water splitting and degradation of indigo carmine dye

Graphitic carbon nitride (g-C3N4) is robust and stable metal free polymeric materials that have recently gained interest towards photocatalytic applications. It shows visible-light driven photocatalytic activity with a major drawback of higher recombination rate of charge carriers and moderate oxidation ability. These issues are overcome by structural modifications using facile polymerization of acidized melamine thus controlling the structure of graphitic carbon nitride. The major factors affecting the photocatalytic activity were experimentally optimized and effect of these parameters was evaluated using the Box–Behnken Design of response surface methodology. The fabricated fibrous graphitic carbon nitride (NFgCN) shows a superior activity of 81.0 μmol g−1 h−1 hydrogen generation and 99.9 % degradation of indigo carmine (IC) dye in 90 min. The NFgCN shows 5 times higher activity for hydrogen generation compared to the pristine g-C3N4.

Construction and mechanism insights of a novel all-solid-state Z-scheme Mo2C/C/BiOI heterojunction for boosted photocatalytic degradation and reduction efficiency

Interfacial configuration of heterostructured photocatalysts to boost photocarrier separation and transfer is immensely beneficial to acquire great photocatalytic efficiency. Herein, a well-structured Mo2C/C/BiOI heterostructure containing different weight ratios Mo2C instead of noble metal was successfully prepared, where the inter-modified carbon nanosheets subserve as a connective to generate a perfect interface contact between Mo2C and BiOI. The photocatalytic performances of the photocatalysts were appraised by the degradation of indigo carmine and reduction of 4-nitroaniline under visible-light elucidation. The nanocomposite containing 7 % by weight of Mo2C/C showed the highest photocatalytic efficiency by eliminating 99.4 % of indigo carmine and 99.8 % of 4-nitroaniline within 75 min and 13 min, respectively. The boosted photocatalytic activity is attributed to the synergistic interaction between Mo2C/C and BiOI and the all-solid-state Z mechanism, where conductive carbon nanoparticles as an efficient electron mediator enable rapid photocarrier transfer and separation between Mo2C and BiOI. This study accentuates that Mo2C/C-based all-solid-state Z-scheme heterojunction nanocomposites are hopeful candidate photocatalysts for environmental applications.

Luminescence and photocatalytic degradation of indigo carmine in the presence of Sm3+doped ZnS nanoparticles

Industrial wastewater discharge is well acknowledged to constitute a significant environmental and public health risk. In addition, synthetic dyes used in the textile sector are major culprits in water pollution. The amount of water polluted by these dyes is simply staggering. We urgently address this issue to protect our planet and health. The degradation of indigo carmine dye in the presence of Sm3+-doped ZnS nanoparticles is reported in this study and characterized by XRD, FTIR, SEM, EDX, TEM, BET, PL, UV, etc. The particle size calculated from the Scherrer equation was 3–12 nm. When excited at 395 nm, Sm3+ undergoes f–f transitions, which are visible as prominent peaks in the photoluminescence spectrum at 559, 595, and 642 nm wavelengths. The catalyst showed vigorous catalytic activity for dye degradation, with a 93% degradation rate when used at 15 mg/L catalyst within 210 min. The reaction was found to have pseudo-first-order kinetics. After applying the Freundlich and Langmuir data, the Langmuir isotherm offered the best fit. The findings indicate that the Sm3+-doped ZnS catalyst might be successfully used in the degradation of dyes present in the environment. Doping with Sm3+ ions can significantly change the photocatalytic breakdown of indigo carmine and the luminescence characteristics of ZnS.

Environmental remediation promoted by silver nanoparticles biosynthesized by eucalyptus leaves extract

A simple and low-cost green synthesis method was optimized to prepare stable silver nanoparticles (AgNP) using aqueous Eucalyptus globulus leaves extract. This green method allows to obtain AgNP with spherical morphology and variable size around 25 nm, and it is dependent of the reaction temperature and concentration of the plant extract. AgNP stability was followed during 3 months by zeta potential measurements and a negative zeta range from −30.7 to −33.6 was determined. Biogenic-stabilized AgNP exhibited dual-functional properties as effective in environmental remediation with bacterial growth inhibition and dye photodegradation. Staphylococcus aureus and Escherichia coli were tested for antibacterial activity, and considerable inhibitory activity was found. High photocatalytic degradation of indigo carmine (IC) dye was performed in the presence of the AgNP as catalysts under sunlight irradiation. The degradation efficiency after 2 h of reaction was 37 %, 83 % and 98 % in the presence of UV light, visible light and sunlight irradiation, respectively. The germination of corn kernels test was used to determine the toxicity of the treated IC solutions and the results showed low toxicity after the photodegradation process.

Surface functionalized multi-wall carbon nanotubes for degradation of organic dyes

Eliminating the hazardous dyes from the wastewater is essential for the sustainable furtherance of eco-friendly-oriented industrial growth. The untreated effluents containing dyes can damage the ecosystem and cause serious health issues to humans, animals, and aquatic species. In the present work, the multi-wall carbon nanotubes (MWCNTs) were functionalized using the combination of sulphuric acid and nitric acid. These functionalized multi-wall carbon nanotubes (F-MWCNTs) were characterized using Fourier transform infrared spectroscopy (FTIR) and energy dispersive X-ray analysis (EDAX) to confirm the presence of functional groups. The catalytic dye degradation efficiency of pristine multi-wall carbon nanotubes (P-MWCNTs) and F-MWCNTs was tested for methylene blue (MB), and indigo carmine (IC) dyes under dark and ultraviolet (UV) light exposure conditions. F-MWCNTs have exhibited appreciable degradation efficiency (∼90%) under dark and UV light compared to P-MWCNTs. An increment in efficiency was observed for UV-light-aided dye degradation. The impact of pH and temperature on degradation was analyzed in detail. The reaction kinetics was studied to determine the rate constants of the degradation reactions. A substantial quantum efficiency (QE) enhancement was noticed for F-MWCNTs compared to P-MWCNTs for both MB and IC degradation.

Construction of recoverable Ag2SeO3/Ag3PO4/MWCNT/PVDF porous film photocatalyst with enhanced photocatalytic performance for degrading Indigo carmine dye in continuous flow-loop photoreactor

Herein, a facile method was used for fabrication of composite based on Ag2SeO3 and Ag3PO4-Cube nanoparticles by co-precipitation method and subsequently was applied for construction of film composite by a casting solution containing polyvinylidene fluoride (PVDF) matrix, multi-walled carbon nanotubes (MWCNTs) as electron acceptor and carboxymethyl cellulose as a hydrophilic agent and Ag2SeO3/Ag3PO4 as photocatalyst filler via phase inversion technique. The synthesized porous film was used for photo-degradation of indigo carmine (IC) in a continuous flow-loop film photoreactor under LED and sunlight irradiation. The composite properties were described using various analyses such as FE-SEM, EDS, XRD, FTIR, PL and UV-Vis, EIS, Bode phase and water contact angle. The Ag2SeO3/Ag3PO4/MWCNT/PVDF film exhibits extensive photocatalytic activities for IC degradation in comparison to MWCNT/PVDF and Ag2SeO3/Ag3PO4 samples. According to the desirability function at optimum conditions lead to the IC photo-degradation efficiency of was around 97.88%. The enhanced visible light-based photocatalytic performance can be attributed to the high charge separation and the surface plasmon resonance (SPR) effect for IC photodegradation and experimental results illustrate that superoxide radicals as the main active radicals has high contribution on the IC photo-degradation. The low decrease in photocatalytic activity of the fabricated composite film after five uses makes the sample suitable for applications where reusability is a vital factor.

TiO2-CoFe2O4 and TiO2-CuFe2O4 Composite Films: A New Approach to Synthesis, Characterization, and Optical and Photocatalytic Properties

Here, we report a new simple and fast method of cobalt and copper ferrites film fabrication on the Ti/TiO2 surface. The approach is based on the deposition of gelatin gel containing copper and cobalt nitrates on the surface of porous oxide-silicon coatings on titanium obtained by plasma electrolytic oxidation (PEO) followed by two-stage annealing at 300 °C and 800 °C to yield ferrite films with good adhesion to PEO layer. The presence of Co/Cu ferrite phases was confirmed by EDX analysis, XRD, and Mössbauer spectroscopy. TiO2-CoFe2O4 and TiO2-CuFe2O4 composite films have excellent performance in the photocatalytic degradation of indigo carmine as a model dye at pH 3 under UV and visible irradiation. The suggested approach to obtain ferrite/TiO2 composite films is promising for the development of magnetic materials, sensors, catalysts, and photocatalysts for various applications.

Bi-metalic ZIFs(Zn-M) (M: Co, Ni) for photocatalytic removal of organic pollutants in aqueous solutions

In this study, we successfully synthesised bi-metallic ZIF(Zn-M) of 2-methyl imidazole with a second metal (cobalt or nickel) binding to the ZIF network. All ZIF samples were synthesised at room temperature and characterised by using XRD, FT-IR, SEM, DRS, and nitrogen adsorption and desorption isotherms. The materials have high crystallinity with a large surface area. The materials’ photocatalytic ability was examined via the degradation of indigo carmine under a sun-light simulator. The second metal enhanced the photon harvesting ability of ZIF(Zn) because the materials can absorb photons in both UV and visible regions. Of the two catalysts, ZIF(Zn-Co) exhibited high photocatalytic ability when it removed 100% of indigo carmine from an aqueous solution. The catalyst adsorbed 45% of indigo carmine after 2 h and entirely degraded the remaining dye dring 1.5 h of solar irradiation. While Co2+ increased the catalyst’s surface area, Ni2+ reduced it, leading to lower photocatalytic efficiency.

Pulsed laser-induced dewetting to fabricate Au-Pd nanoparticles supported on ZnO films and its application for the photocatalytic degradation of indigo carmine

Gold-palladium (Au-Pd) bimetallic alloy nanoparticles (NPs) were obtained by the interaction of a laser pulse with a stack of Au and Pd thin films, these films were previously and sequentially deposited on a zinc oxide (ZnO) thin films grown on a glass substrate. This method can produce, with a single laser pulse, spherical NPs of different compositions which remain attached to the surface of the ZnO film. X-ray diffraction analysis showed that the NPs are composed of a solid solution of the metals whose relative content was modified by varying the deposition time of the starting metal films. The higher amount of Pd in the NPs, the smaller particle size being the minimum around 50 nm. To demonstrate the usefulness of this method to produce Au-Pd NPs directly on surfaces, the decorated ZnO layers were tested as photocatalysts material for the decomposition of indigo carmine dye. The bimetallic NPs supported on ZnO showed to have a better photocatalytic performance to decompose the dye than their mono-metallic counterpart and bare ZnO thin film. The bimetallic NPs richer in Pd achieved a degradation of 99% of the dye while bare ZnO film reached just 32%.

Sustainable waste textile upcycling by selective dye decoloration using ionic liquid and Bi11VO19 photocatalyst

Since a large amount of waste polyester-cotton blended textiles can cause environmental pollution problems, it is crucial to develop sustainable technology for recycling textile wastes and producing value-added products. In this research, regenerated cellulose and polyester were obtained from the polyester-cotton jean wastes by a sustainable process through the selective dissolving of cellulose fibers using an ionic liquid (ILs), 1-butyl-3-methylimidazolium chloride ([Bmim]Cl). We developed an environmentally benign decoloration approach without the bleaching or leaching processes. Instead, cellulose, polyester, and ILs were recycled from the selective degradation of indigo carmine (IC) or indigo dye in the dye/ILs solution using the Bi11VO19 photocatalyst without impairing the dissolution capability of ILs. The selective decoloration of dye solution extracted from waste textiles involves interactions among photocatalysts, colorants, fibers, and media (ILs). The changes of dye and ILs molecules during the photocatalysis reaction were analyzed. FTIR and Raman spectra of the recycled ILs reveal that the chemical structure of ILs remains unchanged after the photocatalytic decoloration process. The ILs and photocatalysts can be recycled for repeated production of regenerated cellulose from waste jeans.

Photocatalytic Denitrification of Nitrate Using Fe-TiO2-Coated Clay Filters

In this work, 3D-structured clay filters were prepared and coated with iron-doped titanium dioxide (Fe-TiO2) using 3D printing and sol–gel soaking and calcination techniques. Three-dimensional printing was employed to mold and shape the clay filters before annealing. The coated and uncoated filters were characterized for different properties, i.e., morphology, optical properties, and crystalline structure, using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), UV/Vis diffused reflectance spectroscopy (DRS), and X-ray diffraction (XRD). The FESEM images show uniform coatings of round-shaped Fe-TiO2 on the tiny pore of the clay filter. The optical energy band gap of the obtained coating was around 2.8 eV, estimated by Tauc’s plot, compared with 3.2 eV of pristine anatase TiO2. The XRD spectra data processed through XRD software revealed the coatings of TiO2 on the filter surface with the obtained phase of anatase. The photocatalytic performance of bare and coated filters was initially tested for the degradation of indigo carmine (IC) dye and the obtained results suggested the photocatalytic degradation of IC dye by the Fe-TiO2 clay filter compared with the bare filter. Afterward, the denitrification of nitrate NO3 at various concentrations was performed using Fe-TiO2-coated clay filters and analyzing the total nitrogen (TN) analysis and reduction of NO3 to nitrite (NO2−), nitrogen monoxide (NO), and nitrogen gas (N2). The TN analysis revealed up to 81% denitrification efficiency of the 30 ppm NO3 solution with the photocatalytic response of the Fe-TiO2-coated filter. The results revealed that the Fe-TiO2-coated clay filter has a high potential for denitrification applications under natural sunlight.

Görünür Işık Altında İndigo Karminin Fotodegradasyonunu Artırmak için CaTiO3/g-C3N4 Heteroyapısının Sentezlenmesi

A series of graphitic carbon nitride (CN) modified CaTiO3 (CTO) composites were synthesized and applied to photodegradation of indigo carmine (IC) The CTO/CN(III) heterostructure exhibited the highest photocatalytic performance for IC degradation under visible light irradiation. The degradation rate constants of IC by the optimal sample were 1.69 and 10.50 times that of CN and CTO, respectively. This could be attributed to the effective separation of photoexcited carriers easier. The photocatalyst dosage increased the removal efficiency, while the initial dye concentration negatively affected the IC degradation rate. Under acidic atmosphere, the catalyst showed superior degradation rate. Furthermore, the active substance (•O2 ¯) was the major active substance for IC photodegradation. On this basis, the possible photocatalytic reaction mechanism of CTO/CN(III) sample was proposed. In addition, the composite achieved considerable performance in ions-included water bodies, namely tap water and drinking water. This study provides a promising and stable photocatalyst as a graphitic carbon nitride modified with calcium-based perovskite for dye removal.