In situ generated nickel on cerium oxide nanoparticle for efficient catalytic reduction of 4-nitrophenol

RSC Advances ◽  
2016 ◽  
Vol 6 (51) ◽  
pp. 45947-45956 ◽  
Author(s):  
S. Vivek ◽  
P. Arunkumar ◽  
K. Suresh Babu
Keyword(s):  
Cerium Oxide ◽  
Absorption Spectra ◽  
Catalytic Reduction ◽  
Reduction Process ◽  
Reducing Agent ◽  
Oxide Nanoparticle ◽  
Uv Visible ◽  
P Absorption

Absorption spectra recorded using UV-visible spectrometer during the reduction process of 4-nitrophenol to 4-aminophenol in the presence of reducing agent (NaBH4) and catalyst (Ni(NO3)2/CeO2).

scholarly journals Poly(N-isopropylacrylamide-co-methacrylic acid) microgel stabilized copper nanoparticles for catalytic reduction of nitrobenzene

2015 ◽  
Vol 33 (3) ◽  
pp. 627-634 ◽  
Author(s):  
Zahoor H. Farooqi ◽  
Zonarah Butt ◽  
Robina Begum ◽  
Shanza Rhauf Khan ◽  
Ahsan Sharif ◽  
...  
Keyword(s):  
Copper Nanoparticles ◽  
Methacrylic Acid ◽  
Catalytic Reduction ◽  
Aqueous Media ◽  
Activation Parameters ◽  
Reducing Agent ◽  
Different Temperatures ◽  
Entropy Of Activation ◽  
Micro Reactors

Abstract Poly(N-isopropylacrylamide-co-methacrylic acid) microgels [p(NIPAM-co-MAAc)] were synthesized by precipitation polymerization of N-isopropylacrylamide and methacrylic acid in aqueous medium. These microgels were characterized by dynamic light scattering and Fourier transform infrared spectroscopy. These microgels were used as micro-reactors for in situ synthesis of copper nanoparticles using sodium borohydride (NaBH4) as reducing agent. The hybrid microgels were used as catalysts for the reduction of nitrobenzene in aqueous media. The reaction was performed with different concentrations of cat­alyst and reducing agent. A linear relationship was found between apparent rate constant (kapp) and amount of catalyst. When the amount of catalyst was increased from 0.13 to 0.76 mg/mL then kapp was increased from 0.03 to 0.14 min-1. Activation parameters were also determined by performing reaction at two different temperatures. The catalytic process has been discussed in terms of energy of activation, enthalpy of activation and entropy of activation. The synthesized particles were found to be stable even after 14 weeks and showed catalytic activity for the reduction of nitrobenzene.

Utility of solid phase extraction for UV-visible spectrophotometric determination of gallium in environmental and biological samples

RSC Advances ◽  
2016 ◽  
Vol 6 (3) ◽  
pp. 1938-1944 ◽  
Author(s):  
Alaa S. Amin ◽  
Sayed M. N. Moalla
Keyword(s):  
Solid Phase Extraction ◽  
Absorption Spectra ◽  
Biological Samples ◽  
Solid Phase ◽  
Phase Extraction ◽  
Optimum Conditions ◽  
Environmental And Biological Samples ◽  
Uv Visible ◽  
P Absorption

Absorption spectra for 2 × 10−5 M BTAHN complexed with 0.5 μg mL−1 Ga(III) at the optimum conditions.

Engineering of silver nanoparticle fabricated poly (N-isopropylacrylamide-co-acrylic acid) microgels for rapid catalytic reduction of nitrobenzene

2016 ◽  
Vol 36 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Zahoor H. Farooqi ◽  
Khalida Naseem ◽  
Aysha Ijaz ◽  
Robina Begum
Keyword(s):  
Acrylic Acid ◽  
Rate Constant ◽  
Apparent Rate Constant ◽  
Reduction Method ◽  
Catalytic Reduction ◽  
Visible Spectroscopy ◽  
Uv Visible ◽  
Polymerization Method ◽  
Hybrid Microgels

Abstract Three different poly(N-isopropylacrylamide-co-acrylic acid) [p(NIPAM-AA)] microgel samples were prepared using a precipitation polymerization method by varying the concentration of NIPAM and AA in aqueous medium. The microgels were used as microreactors to fabricate Ag nanoparticles (NPs) by in situ a reduction method. Fourier transform infrared (FTIR) and UV-visible spectroscopy were used to characterize the pure and hybrid microgels. The hybrid microgels with different AA content were used as catalysts for reduction of nitrobenzene (NB) into aniline. The progress of the reaction was monitored by a UV-visible spectrophotometer. The results show that the value of the apparent rate constant for catalytic reduction of NB decreases from 0.431 min-1 to 0.227 min-1 by increasing AA content from 3 mol% to 7 mol%, respectively. Decrease in apparent rate constant with increase of AA content can be attributed to an increase in hydrophilicity with increase of AA contents of the microgels. The increase in induction period with increase of AA contents indicates that diffusion of NB towards the catalytic surface becomes difficult due to an increase of hydrophilicity.

In situ, multiparameter optical sensor for monitoring the selective catalytic reduction process of diesel engines

2018 ◽  
Vol 267 ◽  
pp. 255-264 ◽  
Author(s):  
Zhenhui Du ◽  
Yue Yan ◽  
Jinyi Li ◽  
Shuai Zhang ◽  
Xiaotao Yang ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Diesel Engines ◽  
Optical Sensor ◽  
Catalytic Reduction ◽  
Reduction Process

Numerical Study of Selective Non-Catalytic Reduction Process in Large Utility Boiler

2013 ◽  
Vol 732-733 ◽  
pp. 258-264
Author(s):  
Qing Xi Cao ◽  
Hui Liu ◽  
Shao Hua Wu ◽  
Wen Yan Wu ◽  
Sui Ying Yu ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Catalytic Reduction ◽  
Numerical Study ◽  
Reduction Process ◽  
Calculation Model ◽  
Industrial Test ◽  
Reducing Agent ◽  
Injection System ◽  
No Removal ◽  
Utility Boiler

To provide a theoretical guidance for the application of selective non-catalytic reduction (SNCR) in a large capacity utility boiler, numerical study of SNCR process in a 600 MW utility boiler was performed based on computational fluid dynamics (CFD) code Fluent. Good agreement of the calculation results with the industrial test data confirms the reliability of the calculation model. It is found that the NO removal efficiency is low and NH3-slip is high, because the injected reducing agent could not mix with the flue gas adequately, and the furnace temperature is not uniform in utility boiler with large furnace size. Aiming at this problem, the commissioning scheme for reducing agent injection system was optimized, and CO was added together with the reducing agent. As a result, NO removal efficiency increases from 19% to 27%, and NH3-slip decreases from 59 ppm to 13 ppm.

In situ green synthesis of Au nanoparticles onto polydopamine-functionalized graphene for catalytic reduction of nitrophenol

RSC Advances ◽  
2014 ◽  
Vol 4 (110) ◽  
pp. 64816-64824 ◽  
Author(s):  
Jing Luo ◽  
Nan Zhang ◽  
Ren Liu ◽  
Xiaoya Liu
Keyword(s):  
Catalytic Activity ◽  
Green Synthesis ◽  
Au Nanoparticles ◽  
Catalytic Reduction ◽  
Reducing Agent ◽  
Functionalized Graphene ◽  
Au Nps ◽  
Surface Modifier ◽  
Green Route

A simple and green route was demonstrated to prepare graphene/Au NPs nanocomposite using polydopamine as surface modifier, reducing agent and stabilizer simultaneously, which exhibits remarkable catalytic activity for the reduction of 4-nitrophenol.

In-situ stabilization of silver nanoparticles in polymer hydrogels for enhanced catalytic reduction of macro and micro pollutants

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Luqman Ali Shah ◽  
Rida Javed ◽  
Mohammad Siddiq ◽  
Iram BiBi ◽  
Ishrat Jamil ◽  
...  
Keyword(s):  
Catalytic Reduction ◽  
Thermo Gravimetric Analysis ◽  
Activation Parameters ◽  
Reduction Reaction ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
In Situ Stabilization ◽  
Hybrid Hydrogels ◽  
Kinetics Of

AbstractThe in-situ stabilization of Ag nanoparticles is carried out by the use of reducing agent and synthesized three different types of hydrogen (anionic, cationic, and neutral) template. The morphology, constitution and thermal stability of the synthesized pure and Ag-entrapped hybrid hydrogels were efficiently confirmed using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and thermo gravimetric analysis (TGA). The prepared hybrid hydrogels were used in the decolorization of methylene blue (MB) and azo dyes congo red (CR), methyl Orange (MO), and reduction of 4-nitrophenol (4-NP) and nitrobenzene (NB) by an electron donor NaBH4. The kinetics of the reduction reaction was also assessed to determine the activation parameters. The hybrid hydrogen catalysts were recovered by filtration and used continuously up to six times with 98% conversion of pollutants without substantial loss in catalytic activity. It was observed that these types of hydrogel systems can be used for the conversion of pollutants from waste water into useful products.

scholarly journals Development of antibacterial and UV protective cotton fabrics using plant food waste and alien invasive plant extracts as reducing agents for the in-situ synthesis of silver nanoparticles

Cellulose ◽  
2021 ◽  
Author(s):  
Nina Čuk ◽  
Martin Šala ◽  
Marija Gorjanc
Keyword(s):  
Silver Nanoparticles ◽  
Green Tea ◽  
Food Waste ◽  
Cotton Fabrics ◽  
Reducing Agent ◽  
Plant Food ◽  
Japanese Knotweed ◽  
Tea Leaves ◽  
Green Tea Leaves

Abstract The development of cellulose-based textiles that are functionalised with silver nanoparticles (AgNP), synthesised according to a green approach, and offer protection against ultraviolet (UV) radiation and pathogenic bacteria is very important today. In the present work we demonstrate the environmentally friendly approach to obtain such textile material by AgNP synthesis directly (in-situ) on cotton fabrics, using water extracts of plant food waste (green tea leaves, avocado seed and pomegranate peel) and alien invasive plants (Japanese knotweed rhizome, goldenrod flowers and staghorn sumac fruit) as reducing agents. The extracts were analysed for their total content of phenols and flavonoids and their antioxidant activity. The synthesised AgNP on cotton were round, of different size and amount depending on the reducing agent used. The highest amount of AgNP was found for samples where Japanese knotweed rhizome extract was used as reducing agent and the lowest where extracts of goldenrod flowers and green tea leaves were used. Regardless of the reducing agent used to form AgNP, all cotton samples showed excellent protection against E. coli and S. aureus bacteria and against UV radiation with UV protection factor values above 50. The best results for UV protection even after the twelve repetitive washing cycles were found for the sample functionalized with AgNP synthesised with an extract of the Japanese knotweed rhizome. Due to the presence of AgNP on cotton, the air permeability and thermal conductivity decreased. AgNP had no effect on the change in breaking strength or elongation of fabrics. Graphic abstract

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