Degradation Of 4-nitrophenol Research Articles

A wood-based fluid catalytic reactor with directional channels and porous inner walls for efficient degradation of 4-NP by immobilized laccase

Modern bioreactors primarily focus on fixing enzymes on materials to form fixed bed reactors, but the reaction efficiency is unstable. More importantly, the enzymes easily fall off or even inactivate, and the fluid risks leaking due to excessive pressure during flow. In this study, a directional channel continuous microfluidic reactor with laccase covalently immobilized in the internal channel is made from natural wood. After dimethylacetamide/lithium chloride (DMAc/LiCl) treatment of delignified wood, the micropores (ray cells, pits and nanopores) in directional channel walls are fully exposed. When the fluid passes through, the turbulence near the pits increases, resulting in good mass and heat transfer, which enhances the catalytic efficiency of laccase. The reactor has good stability and maintains more than 80% substrate conversion in the pH range of 3–7 and the temperature range of 15–55 ℃. In the degradation of 4-nitrophenol (4-NP), a 94.42% degradation rate is achieved in only 30 min, and 86.93% efficiency is maintained after 25 cycles of catalysis, indicating its excellent reusability. The directional reactor with porous inner walls is simple to prepare and easy to scale up, which provides excellent convenience for continuous industrial production and shows great commercial application potential.

Biopolymer-based trimetallic nanocomposite synthesis, characterization and its application in the catalytic degradation of 4-nitrophenol

Biopolymer-based trimetallic nanocomposite synthesis, characterization and its application in the catalytic degradation of 4-nitrophenol

Synthesis and Characterization of New Catalysts Grains Based on Iron(Oxy)Hydroxides supported on Zirconium for the Degradation of 4-Nitrophenol in Aqueous Solution

This study reports the preparation of catalyst grains based on oxyhydroxides of iron and zirconium via the coprecipitation method and their application in the degradation of 4-nitrophenol. The morphology, microstructure, and surface composition of these catalysts were characterized by scanning electron microscopy, X-ray diffraction, nitrogen physisorption, and Fourier transform infrared spectroscopy. The catalytic activity of the grains was assessed in the degradation of 4-nitrophenol in a heterogeneous system at different operating conditions. Degradation rates up to 93% were obtained after 4 h of contact time where the catalytic activity of tested materials was higher at pH 7 than in acidic and basic conditions. Amorphous iron hydroxide with a ratio of 75% Zr+25%Fe showed the best catalytic properties. These novel materials are an interesting alternative for facing the water pollution caused by organic compounds.

Ultrathin g-PAN/PANI-encapsulated Cu nanoparticles decorated on SrTiO3 with high stability as an efficient photocatalyst for the H2 evolution and degradation of 4-nitrophenol under visible-light irradiation

Ultrathin PANI-doped g-PAN not only serves as the encapsulating agent to protect Cu from oxygen attack, but it also improves the efficiency of electron–hole separation, thereby enhancing the photocatalytic hydrogen evolution efficiency.

Influence of capping agents on morphology and photocatalytic response of ZnS nanostructures towards crystal violet degradation under UV and sunlight

The capped ZnS NPs (ZnSM1 and ZnSM2) found to be highly photoactive towards crystal violet (CV) dye. Nearly 93% and 88% degradation of CV was observed under UV and sunlight whereas very efficiency was shown by uncapped (ZnSUC) and standard ZnS nanostructures. • Different capping agents influenced morphology of ZnS NPs. • Successful passivation of functional groups over ZnS surface. • Surface defects made ZnSM1 and ZnSM2 quite photo-responsive under sunlight. • Efficient photostability determined by recyclability of ZnSM1 and ZnSM2. • 88% of CV degradation was observed using ZnSM1 under sunlight. Photo-responsive ZnS nanostructures (ZnSM1 and ZnSM2) were synthesized using 3-mercaptopropionic acid (MPA) and polyvinylpyrrolidone (PVP) capping agents respectively via reflux method. Capped photocatalysts hold unique optical properties such as absorption in visible region, multi band gap values and surface defects. Interestingly, structural analysis revealed that nanorods and nanospheres were formed with MPA and PVP whereas randomly arranged particles were formed without using any capping agent (ZnSUC). The successful passivation of COOH (1549 cm −1 and 1357 cm −1 ) in case of ZnSM1 whereas CH 2 (1284 cm −1 ) and C N stretching (1429 cm −1 ) for ZnSM2 was determined by FT-IR studies. Owing to effective charge separation, 1D structure, suitable band gap energies and higher surface area (252 m 2 g −1 ), ZnSM1 exhibited enhanced photocatalytic activity towards crystal violet degradation (CV, 93%) under UV light which was about two folds higher than standard ZnS. Under sunlight, uncapped ZnS nanoparticles (ZnSUC and std. ZnS) showed minor activity in comparison to capped ZnSM1 (88%) and ZnSM2 (77%). Moreover, 83% degradation of 2-nitrophenol (NP) was obtained using ZnSM1 without using any other reducing agent under solar irradiations. Thus, present work provides more insights to understand the outstanding activity of ZnS nanomaterials towards organic pollutants beyond UV region without metal deposition.

Electrocatalytic Degradation of Methyl Orange and 4-Nitrophenol on a Ti/TiO

Electrocatalytic Degradation of Methyl Orange and 4-Nitrophenol on a Ti/TiO

Co — Ni — Zn nanoferrites: magnetic and photocatalytic properties for the decomposition of 4-nitrophenol

The paper considers changes in the magnetic and catalytic properties of Co- Ni- Zn ferrites by drawing up plans Scheffe’s plans. Three-component ferrites were obtained using coprecipitation and glow dischage treatment. It was found that the saturation magnetization decreases for Ni- Zn ferrites with increasing Zn content, high values for the entire series of Co- Zn, Co-Ni ferrites are observed. The study of catalytic activity in relation to the decomposition reaction of 4-nitrophenol showed excellent results for all compositions. The effect of the mutual influence of the content of different cations on the photocatalytic properties is clearly traced. Ferrites containing one cation in the composition have lower photocatalytic activity. Using UV-spectroscopy, the mechanism of 4-nitrophenol (4-NP) degradation was established.

Magnetic recoverable Cu/CuFe2O4 nanocomposite as an efficient catalyst for 4-nitrophenol reduction and methylene blue degradation

In this study, the magnetic Cu/CuFe2O4 nanocomposite was successfully prepared by a one-pot solvothermal method and evaluated for catalytic activity in the 4-nitrophenol (4-NP) reduction reaction and methylene blue (MB) degradation reaction. The structure, surface morphology, and properties of this catalyst were characterized by using several physicochemical methods such as Powder X-ray diffraction (PXRD), Fourier-transform infrared spectroscopy (FT-IR), UV-Vis diffuse reflectance spectroscopy (DRS), Brunauer–Emmett–Teller (BET), field emission scanning electron microscopy (FE-SEM), EDX mapping, and vibrating sample magnetometer (VSM). The Cu/CuFe2O4 catalyst is spherical in shape with an average diameter of about 145 nm and a BET surface area (SBET) of 52 m2.g-1. In both the 4-NP reduction and MB degradation reactions, this nanocomposite material showed high catalytic activity. The yield of 4-NP reduction reaction in the presence of NaBH4 was 82% after 5 minutes. In this reaction, Cu metal both plays the role of direct electron transfer from BH4- ions to 4-NP and participates in and promotes the electron transfer process between Cu+-Cu2+ and Fe2+-Fe3+ ion pairs in CuFe2O4. For MB degradation reaction, under the stimulation of UVA radiation with the presence of oxalic acid (H2C2O4) as a free radical-generating agent, the reaction yield was 98% after 40 minutes. In this process, Cu is an electron donor to reduce Fe3+ to Fe2+ in the CuFe2O4 structure, contributing to promoting the formation of highly active free radicals to decompose MB. The catalytic efficiency, crystal structure, and morphology of Cu/CuFe2O4 nanocomposite were stable over five consecutive uses in both two reactions.

A Recyclable Photocatalyst Cu2o/Fe3o4@C/Cu Nanocomposite for Efficient Photocatalytic Degradation of 4-Nitrophenol

A Recyclable Photocatalyst Cu2o/Fe3o4@C/Cu Nanocomposite for Efficient Photocatalytic Degradation of 4-Nitrophenol

Template synthesis of dual-functional porous MoS2 nanoparticles with photothermal conversion and catalytic properties.

Advanced catalysis triggered by photothermal conversion effects has aroused increasing interest due to its huge potential in environmental purification. In this work, we developed a novel approach to the fast degradation of 4-nitrophenol (4-Nip) using porous MoS2 nanoparticles as catalysts, which integrate the intrinsic catalytic property of MoS2 with its photothermal conversion capability. Using assembled polystyrene-b-poly(2-vinylpyridine) block copolymers as soft templates, various MoS2 particles were prepared, which exhibited tailored morphologies (e.g., pomegranate-like, hollow, and open porous structures). The photothermal conversion performance of these featured particles was compared under near-infrared (NIR) light irradiation. Intriguingly, when these porous MoS2 particles were further employed as catalysts for the reduction of 4-Nip, the reaction rate constant was increased by a factor of 1.5 under NIR illumination. We attribute this catalytic enhancement to the open porous architecture and light-to-heat conversion performance of the MoS2 particles. This contribution offers new opportunities for efficient photothermal-assisted catalysis.

Control-Synthesized Ultrafine AU Nanoparticles by Aspergillus Niger Extracellular Metabolites from Sim Cards as High-Effective 4-Nitrophenol Degradation Catalyst

Control-Synthesized Ultrafine AU Nanoparticles by Aspergillus Niger Extracellular Metabolites from Sim Cards as High-Effective 4-Nitrophenol Degradation Catalyst

Synthesis of silver nanoparticles in a plasma electrochemical system for degradation of environmental pollutants

We demonstrate operation of an aqueous electrochemical cell with an atmospheric-pressure contact non-equilibrium low-temperature plasma (CNP) anode and a solid metal cathode for the rapid production of colloidal metal nanoparticles. CNP was utilized to synthesize Ag nanoparticles (AgNPs). The synthesized AgNPs were characterized by using UV–vis spectroscopy, dynamic light scattering, transmission electron microscope. The effect of concentration of Ag+ and type of stabilizing agent on the production of silver nanoparticles has been studied. To optimize the synthesis process the main characteristics of the discharge plasma were studied using UV-spectroscopy by varying the discharge current and solution composition. The AgNPs solution showed catalytic activity for the complete degradation of 4-nitrophenol (4-NPh).

Antibacterial Films of Alginate-CoNi-Coated Cellulose Paper Stabilized Co NPs for Dyes and Nitrophenol Degradation.

The development of a solid substrate for the support and stabilization of zero-valent metal nanoparticles (NPs) is the heart of the catalyst system. In the current embodiment, we have prepared solid support comprise of alginate-coated cellulose filter paper (Alg/FP) for the synthesis and stabilization of Co nanoparticles (NPs) named as Alg/FP@Co NPs. Furthermore, Alginate polymer was blended with 1 and 2 weight percent of CoNi NPs to make Alg-CoNi1/FP and Alg-CoNi2/FP, respectively. All these stabilizing matrixes were used as dip-catalyst for the degradation of azo dyes and reduction of 4-nitrophenol (4NP). The effect of initial dye concentration, amount of NaBH4, and catalyst dosage was assessed for the degradation of Congo red (CR) dye by using Alg-CoNi2/FP@Co NPs. Results indicated that the highest kapp value (3.63 × 10−1 min−1) was exhibited by Alg-CoNi2/FP@Co NPs and lowest by Alg/FP@Co NPs against the discoloration of CR dye. Furthermore, it was concluded that Alg-CoNi2/FP@Co NPs exhibited strong catalyst activity against CR, and methyl orange dye (MO) degradation as well as 4NP reduction. Antibacterial activity of the prepared composites was also investigated and the highest l activity was shown by Alg-CoNi2/FP@Co NPs, which inhibit 2.5 cm zone of bacteria compared to other catalysts.

Fe3O4 nanoparticle decorated novel magnetic metal oxide microcomposites for the catalytic degradation of 4-nitrophenol for wastewater cleaning applications

Fe3O4 nanoparticle decorated novel magnetic metal oxide microcomposites for the catalytic degradation of 4-nitrophenol for wastewater cleaning applications

Highly Efficient Simulated Solar Light‐Driven Photocatalytic Degradation of 4‐Nitrophenol over CdS/Carbon/MoSx Hybrids

Among the various organic pollutants and industrial chemicals, 4-nitrophenol has been one of the most monitored substances in aqueous environments, due to its enhanced solubility in such systems. This research reports for the first time the microwave-assisted synthesis of CdS/carbon/MoSx hybrids and the subsequent utilization of such systems as photocatalysts for 4-nitrophenol degradation. The hybrids demonstrated a variable photocatalytic activity, by using a variety of organic substances as precursors for the solvothermal carbonization step. By using ascorbic acid as precursor, the corresponding ternary composite exhibited excellent photocatalytic activity, with the 4-nitrophenol concentration been almost quantitatively decayed within 45 min of irradiation. This could be ascribed due to the generation of a high population of heterojunctions as well as the chemical speciation of Mo-based nanostructures. Such ternary hybrids may be utilized as potential photocatalytic systems in processes, where removal of toxic water-soluble substances is the key issue.

Synthesis of Fe3O4/CdWO4/carbon dots heterostructure with excellent visible light photocatalytic stability and activity for degradation of 4-nitrophenol and organic pollutant

Synthesis of Fe3O4/CdWO4/carbon dots heterostructure with excellent visible light photocatalytic stability and activity for degradation of 4-nitrophenol and organic pollutant

Spectroscopic characterization, X-ray molecular structures and cyclic voltammetry study of two (piperazine) cobalt(II) meso-arylporphyin complexes. Application as a catalyst for the degradation of 4-nitrophenol

Two new cobaltous-porphyrin complexes, namely (μ-piperazine)-bis[(meso-tetra(para-methoxyphenyl)porphyrinato)]cobalt(II) and (piperazine)[meso-tetra(para-chlorophenyl)porphyrin]cobalt(II) dichloromethane disolvate, with the formulas [{CoII(TMPP)}2(μ2-pipz)] (complex 1) and [CoII(TClPP)(pipz)]·2CH2Cl2 (complex 2), were used efficiently as catalysts in the degradation of 4-nitrophenol (4-NP) in an aqueous hydrogen peroxide solution. These cobalt(II)-pipz porphyrin complexes were characterized by a variety of spectroscopic methods including infrared, UV–visible, fluorescence, proton nuclear magnetic resonance, electron paramagnetic resonance (EPR) as well as mass spectrometry. A cyclic voltammetry investigation was also carried out on these two Co(II) metalloporphyrins. The EPR results indicate that both complexes 1 and 2 are paramagnetic low-spin (S = 1/2) cobalt(II) porphyrin complexes. Furthermore, the X-ray diffraction crystal structures of 1 and 2 were determined, and the intermolecular interactions were investigated by Hirshfeld surface analysis.

Visible light-assisted degradation of 4-nitrophenol and methylene blue using low energy carbon ion-implanted ZnO nanorod arrays: Effect on mechanistic insights and stability

The present investigation demonstrates an enhancement of the visible photocatalytic activities by C ion implantation in ZnO nanorod arrays (NRAs). Vertically aligned ZnO NRAs were prepared by seed layer assisted solution-phase growth and implanted with 70 keV carbon ions at various fluencies: 1E15, 5E15, 1E16, and 3E16 ions/cm2. X-ray diffraction and FESEM results revealed the crystalline 1D ZnO NRAs having a length of ∼3 μm with a diameter in the range of 150–200 nm. C implantation induces the absorption towards the visible region and a substantial decrease in the optical bandgap energy from 3.2 eV to 2.43 eV. The photocatalytic activities (PC) of C ion-implanted ZnO NRAs were investigated through the degradation of 4-Nitrophenol (4-NP) and methylene blue dye (MB) under ambient visible light irradiation. The degradation efficiency of C ion-implanted ZnO NRAs increases compared to the pristine ZnO NRAs from 60.12% to 93.7% and 48.6 to 97.5% for MB and 4-NP, respectively. The synergistic effects of low energy carbon ion-induced bulk and surface interface electronic states facilitate a narrow band of visible light absorption and efficient charge separation to increase the visible-light-driven photocatalytic performance of ZnO NRAs.

An efficient photocatalytic degradation of nitrophenols using TiO2 as a heterogeneous photo-Fenton catalyst

An efficient photocatalytic degradation of nitrophenols using TiO2 as a heterogeneous photo-Fenton catalyst

Biodegradation of two persistent aromatic compounds by using oil shale

Low-cost oil shale was investigated as a biodegradation promoter material, in order to exploit its potential for more widespread and efficient usage in the elimination of pollution. Degradation of two model pollutants, 4-nitrophenol and phenol, was examined in the presence of oil shale in a batch system. In order to investigate the role of the natural microflora of the oil shale in degradation, sodium azide was added to inhibit microbial growth. The effect of metal ions was also investigated. In the sodium azide-free solutions the model pollutants were completely degraded up to 2000 µmol/L concentration in a dose-dependent way, while the addition of sodium azide delayed greatly but did not stop the degradation. Manganese(II) ions increased the rate of the degradation of 4-nitrophenol, and given quantities of iron(II), manganese(II) or zinc(II) ions were also effective in degradation of phenol. Our results suggest that oil shale is not only an adsorbent but has an active role in the degradation of pollutants by its natural microflora. Utilizing these features of oil shale, it is a suitable candidate as an ameliorating agent, which can also be used in industrial size.