Mechanistic insight into the electrocatalytic performance of reduced graphene oxide supported palladium, silver and palladium–silver nanodeposits toward electro-dehalogenation of halocarbons in room temperature ionic liquids

2020 ◽  
Vol 22 (29) ◽  
pp. 16985-16997
Author(s):  
Sarwar Ahmad Pandit ◽  
Sajad Ahmad Bhat ◽  
Mudasir Ahmad Rather ◽  
Pravin P. Ingole ◽  
Mohsin Ahmad Bhat
Keyword(s):  
Graphene Oxide ◽  
Ionic Liquids ◽  
Reduced Graphene Oxide ◽  
Room Temperature ◽  
Room Temperature Ionic Liquids ◽  
Electrocatalytic Performance ◽  
Reduced Graphene ◽  
Supported Palladium ◽  
Insight Into ◽  
Palladium Silver

The electrocatalytic performance of reduced graphene oxide supported metal nano-deposits toward the electro-dehalogenation of halocarbons in room temperature ionic liquids (RTILs) is related to the mechanistic aspects of the electroreduction.

Rapid Nucleation of Reduced Graphene Oxide-Supported Palladium Electrocatalysts for Methanol Oxidation Reaction

2019 ◽  
Vol 19 (11) ◽  
pp. 7236-7243
Author(s):  
Jen Chao Ng ◽  
Chou Yong Tan ◽  
Boon Hoong Ong ◽  
Atsunori Matsuda ◽  
Wan Jefrey Basirun ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Microwave Irradiation ◽  
Reduced Graphene Oxide ◽  
Oxidation Reaction ◽  
Room Temperature ◽  
Methanol Oxidation Reaction ◽  
Ph Adjustment ◽  
Reduced Graphene ◽  
High Supersaturation ◽  
Supported Palladium

Small sized electrocatalysts, which can be obtained by rapid nucleation and high supersaturation are imperative for outstanding methanol oxidation reaction (MOR). Conventional microwave synthesis processes of electrocatalysts include ultrasonication, stirring, pH adjustment, and microwave irradiation of the precursor mixture. Ethylene glycol (EG), which serves as a reductant and solvent was added during the ultrasonication or stirring stage. However, this step and pH adjustment resulted in unintended multi-stage gradual nucleation. In this study, the microwave reduction approach was used to induce rapid nucleation and high supersaturation in order to fabricate small-sized reduced graphene oxide-supported palladium (Pd/rGO) electrocatalysts via the delayed addition of EG, elimination of the pH adjustment step, addition of sodium carbonate (Na2CO3), prior microwave irradiation of the EG mixed with Na2CO3, and addition of room temperature precursor mixture. Besides its role as a second reducing agent, the addition of Na2CO3 was primarily intended to generate an alkaline condition, which is essential for the high-performance of electrocatalysts. Moreover, the microwave irradiation of the EG and Na2CO3 mixture generated highly reactive free radicals that facilitate rapid nucleation. Meanwhile, the room temperature precursor mixture increased supersaturation. Results showed improved electrochemically active surface area (78.97 m2 g−1, 23.79% larger), MOR (434.49 mA mg−1, 37.96% higher) and stability.

Polyaniline-Reduced Graphene Oxide Nanosheets for Room Temperature NH3 Detection

2021 ◽  
Author(s):  
Junyu Chang ◽  
Xiaobo Zhang ◽  
Zhenming Wang ◽  
Chunsheng Li ◽  
Qi Hu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Room Temperature ◽  
Graphene Oxide Nanosheets ◽  
Reduced Graphene

scholarly journals Green Synthesis of Reduced Graphene Oxide-Supported Palladium Nanoparticles by Coleus amboinicus and Its Enhanced Catalytic Efficiency and Antibacterial Activity

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 134
Author(s):  
Koduru Mallikarjuna ◽  
Lebaka Veeranjaneya Reddy ◽  
Sarah Al-Rasheed ◽  
Arifullah Mohammed ◽  
Sreedevi Gedi ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Palladium Nanoparticles ◽  
Catalytic Efficiency ◽  
Tem Analysis ◽  
Reduced Graphene ◽  
Supported Palladium ◽  
Medical Disciplines ◽  
Coleus Amboinicus

Novel reduced graphene oxide-supported palladium nanoparticles (RGO-PN) were synthesized under ultrasonication, a method that utilizes Coleus amboinicus as a bio-reduction agent. Green synthesized RGO-PN nanoparticles with a crystallite size in the range of 40–50 nm were confirmed in X-ray diffraction (XRD) spectra. RGO-PN show an absorption peak at 220 nm while reduced graphene oxide (RGO) shows its maximal absorbance at 210 nm. The scanning electron microscope image revealed that 40-nm-sized spherical-shaped palladium nanoparticles stick well to reduced graphene oxide sheets, which is consistent and correlated well with the XRD pattern. Moreover, a high-resolution morphological image of RGO-PN100 was obtained by TEM analysis, which shows the anchoring of palladium nanoparticles (PN) on RGO nanosheets. Green synthesized RGO-PN100 nanoparticles from Coleus amboinicus show better reduction kinetics for 4-nitrophenol at 40 min, suggesting that RGO-PN prepared from Coleus amboinicus serve as an excellent catalytic reducing agent. Furthermore, they show remarkable antibacterial activity against Escherichia coli (ATCC 25922). Thus, green synthesized RGO-supported palladium nanoparticles demonstrated that enhanced catalytic activity and antibacterial activity both play an important role in the environmental and medical disciplines.

scholarly journals Functionalized Reduced Graphene Oxide Thin Films for Ultrahigh CO2 Gas Sensing Performance at Room Temperature

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 623
Author(s):  
Monika Gupta ◽  
Huzein Fahmi Hawari ◽  
Pradeep Kumar ◽  
Zainal Arif Burhanudin ◽  
Nelson Tansu
Keyword(s):  
Thin Films ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Gas Sensor ◽  
Functional Groups ◽  
Recovery Time ◽  
Room Temperature ◽  
Co2 Gas ◽  
Reduced Graphene ◽  
Response And Recovery

The demand for carbon dioxide (CO2) gas detection is increasing nowadays. However, its fast detection at room temperature (RT) is a major challenge. Graphene is found to be the most promising sensing material for RT detection, owing to its high surface area and electrical conductivity. In this work, we report a highly edge functionalized chemically synthesized reduced graphene oxide (rGO) thin films to achieve fast sensing response for CO2 gas at room temperature. The high amount of edge functional groups is prominent for the sorption of CO2 molecules. Initially, rGO is synthesized by reduction of GO using ascorbic acid (AA) as a reducing agent. Three different concentrations of rGO are prepared using three AA concentrations (25, 50, and 100 mg) to optimize the material properties such as functional groups and conductivity. Thin films of three different AA reduced rGO suspensions (AArGO25, AArGO50, AArGO100) are developed and later analyzed using standard FTIR, XRD, Raman, XPS, TEM, SEM, and four-point probe measurement techniques. We find that the highest edge functionality is achieved by the AArGO25 sample with a conductivity of ~1389 S/cm. The functionalized AArGO25 gas sensor shows recordable high sensing properties (response and recovery time) with good repeatability for CO2 at room temperature at 500 ppm and 50 ppm. Short response and recovery time of ~26 s and ~10 s, respectively, are achieved for 500 ppm CO2 gas with the sensitivity of ~50 Hz/µg. We believe that a highly functionalized AArGO CO2 gas sensor could be applicable for enhanced oil recovery, industrial and domestic safety applications.

Preparation and enhanced electrocatalytic activity of graphene supported palladium nanoparticles with multi-edges and corners

RSC Advances ◽  
2016 ◽  
Vol 6 (101) ◽  
pp. 98708-98716 ◽  
Author(s):  
Zhelin Liu ◽  
Yinghui Feng ◽  
Xiaofeng Wu ◽  
Keke Huang ◽  
Shouhua Feng ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Electrocatalytic Activity ◽  
Palladium Nanoparticles ◽  
Pd Nanoparticles ◽  
Reduced Graphene ◽  
Point Discharge ◽  
Supported Palladium ◽  
Activity Point

Pd nanoparticles with multi-edges and corners are prepared and assembled on reduced graphene oxide to examine the electrocatalytic activity. Point discharge is regarded to be capable of facilitating the electron transfer.

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