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

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.

RSC Advances ◽  
2016 ◽  
Vol 6 (69) ◽  
pp. 64937-64945 ◽  
Author(s):  
Yajiao Song ◽  
Jianhua Lü ◽  
Bingxin Liu ◽  
Changli Lü

Au NPs were generated via in situ reduction on copolymer brush P(OEGMA-co-MQ) functionalized GO. MQ units in the brushes as capping agents could stabilize the Au NPs. The Au NPs–GO hybrid exhibited high catalytic activity for the reduction of 4-NP.


2015 ◽  
Vol 33 (3) ◽  
pp. 627-634 ◽  
Author(s):  
Zahoor H. Farooqi ◽  
Zonarah Butt ◽  
Robina Begum ◽  
Shanza Rhauf Khan ◽  
Ahsan Sharif ◽  
...  

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.


Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2358 ◽  
Author(s):  
David Lopez-Tejedor ◽  
Blanca de las Rivas ◽  
Jose M. Palomo

A novel heterogeneous enzyme-palladium (Pd) (0) nanoparticles (PdNPs) bionanohybrid has been synthesized by an efficient, green, and straightforward methodology. A designed Geobacillus thermocatenulatus lipase (GTL) variant genetically and then chemically modified by the introduction of a tailor-made cysteine-containing complementary peptide- was used as the stabilizing and reducing agent for the in situ formation of ultra-small PdNPs nanoparticles embedded on the protein structure. This bionanohybrid was an excellent catalyst in the synthesis of trans-ethyl cinnamate by Heck reaction at 65 °C. It showed the best catalytic performance in dimethylformamide (DMF) containing 10–25% of water as a solvent but was also able to catalyze the reaction in pure DMF or with a higher amount of water as co-solvent. The recyclability and stability were excellent, maintaining more than 90% of catalytic activity after five cycles of use.


2017 ◽  
Vol 9 (38) ◽  
pp. 5586-5592 ◽  
Author(s):  
Y. L. Yuan ◽  
G. M. Pang ◽  
X. K. Li ◽  
W. Y. Zhu ◽  
H. C. Pan

A novel strategy for the fabrication of a photoelectrochemical system, involving a duo-dye sensitized Au NPs composite, that displays a specific response to mercury.


2022 ◽  
Author(s):  
Shuyue He ◽  
Di Wu ◽  
Siwei Chen ◽  
Kai Liu ◽  
Eui-Hyeok Yang ◽  
...  

Abstract Dual-functionality Au-on-Ag nanostructures (AOA) were fabricated on a silicon substrate by first immobilizing citrate-reduced Ag nanoparticles (Ag NPs, ~43 nm in diameter), followed by depositing ~7 nm Au nanofilms (Au NFs) via thermal evaporation. Au NFs were introduced for their catalytic activity in concave-convex nano-configuration. Ag NPs underneath were used for their significant enhancement factor (EF) in surface-enhanced Raman scattering (SERS)-based measurements of analytes of interest. Rhodamine 6G (R6G) was utilized as the Raman-probe to evaluate the SERS sensitivity of AOA. The SERS EF of AOA is ~37 times than that of Au NPs. Using reduction of 4-nitrothiophenol (4-NTP) by sodium borohydride (NaBH4) as a model reaction, we demonstrated the robust catalytic activity of AOA as well as its capacity to continuously monitor via SERS the disappearance of reactant 4-NTP, emergence and disappearance of intermediate 4, 4’-DMAB, and the appearance of product 4-ATP throughout the reduction process in real-time and in situ.


2019 ◽  
Vol 55 (27) ◽  
pp. 3967-3970 ◽  
Author(s):  
Xuejiao Yang ◽  
Bohao Yang ◽  
Yuefei Wang ◽  
Wei Qi ◽  
Qiguo Xing ◽  
...  

Based on self-assembly and biomineralization, Au NPs@ferrocene–tryptophan (Fc-W) superstructures were fabricated, exhibiting efficient photothermal effects and catalytic activity.


2015 ◽  
Vol 17 (17) ◽  
pp. 11329-11340 ◽  
Author(s):  
Rajendiran Rajesh ◽  
E. Sujanthi ◽  
S. Senthil Kumar ◽  
Rengarajan Venkatesan

Nanocatalysts based on Ag and AuNPs stabilized over chitosan functionalized GO exhibited excellent catalytic activity towards reduction of nitroarenes and dye degradation.


2016 ◽  
Vol 6 (15) ◽  
pp. 6002-6010 ◽  
Author(s):  
Ryoichi Kanega ◽  
Hitoshi Ogihara ◽  
Ichiro Yamanaka

Electrochemical carbonylation of phenol (PhOH) with CO (1 atm) to form diphenyl carbonate (DPC) was studied by using a Pd-(in situ NHC) electrocatalyst and graphene-supported Au nanoparticle (Au NPs/GR) anodes.


RSC Advances ◽  
2015 ◽  
Vol 5 (57) ◽  
pp. 46240-46246 ◽  
Author(s):  
Mahmoud Nasrollahzadeh ◽  
S. Mohammad Sajadi

This paper reports on the green synthesis of gold nanoparticles (Au NPs) by Anthemis xylopoda flowers aqueous extract without the addition of surfactant agents and their application as stable catalysts for the synthesis of propargylamines.


2012 ◽  
Vol 550-553 ◽  
pp. 220-224
Author(s):  
Chao Xian Wang ◽  
Yong Xiu Li ◽  
Hui Liu ◽  
Long Wei Ye ◽  
Chang Yong Sun ◽  
...  

Impregnation and deposition-precipitation (DP) methods were employed for the preparation of Au nanoparticles supported on SBA-15, and the influences of various reductants were systematically surveyed. The dispersion and particle size of gold loaded on SBA-15 were determined by XRD, SEM and TEM. It has been found that reductants have effect on the size and dispersion of Au NPs, resulting in different catalytic properties for aerobic oxidation of glucose. The Au NPs on SBA-15 using KBH4as reductant was approximately 5-6 nm, which exhibited excellent catalytic activity.


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