Designed functionalization of reduced graphene oxide for sorption of Cr(vi) over a wide pH range: a theoretical and experimental perspective

2018 ◽  
Vol 42 (20) ◽  
pp. 16960-16971 ◽  
Author(s):  
Maloy Kr Mondal ◽  
Debiprasad Roy ◽  
Pranesh Chowdhury
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Reduced Graphene ◽  
Wide Ph Range ◽  
Ph Range

The present study illustrates a clear functionalization chemistry for the synthesis of guanidine functionalized reduced graphene oxide (GfG) for sorption of Cr(VI).

Tuning the cationic ratio of Fe1CoxNiyP integrated on Vertically aligned reduced graphene oxide array via electroless plating as efficient self-supported bifunctional electrocatalyst for water splitting

2021 ◽  
pp. 1-33
Author(s):  
Kaiming Guo ◽  
Firdoz Shaik ◽  
Jine Yang ◽  
Bin Jiang
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Water Splitting ◽  
Electroless Plating ◽  
Cost Effective ◽  
Bifunctional Electrocatalyst ◽  
Reduced Graphene ◽  
Wide Ph Range ◽  
Vertically Aligned ◽  
Ph Range

Abstract Water splitting is considered as a potential sustainable and green technology for producing mass hydrogen and oxygen. A cost-effective self-supported stable electrocatalyst with excellent electrocatalytic performance in a wide pH range is greatly required for water splitting. This work reports on the synthesis and anchoring of Fe1CoxNiyP nanoparticles on vertically aligned reduced graphene oxide array (VrGO) via electroless plating. The catalytic activity of Fe1CoxNiyP nanoparticles is tuned finely by tailoring the cationic ratio of Co and Ni. Fe1Co2Ni1P/VrGO exhibits the lowest overpotential (58 and 110 mV) at 10 mA cm−2 and lowest tafel slope (31 and 33 mV dec−1) for hydrogen evolution reaction in 1.0 M KOH and 0.5 M H2SO4 respectively. Fe1Co1Ni2P/VrGO exhibits the lowest overpotential (173 mV) at 10 mA cm−2 with lowest tafel slope (47 mV dec-1) for oxygen evolution reaction. The enhanced performance of the electrocatalyst is attributed to improved electrical conductivity, synergistic effects and beneficial electronic states caused by the appropriate atomic ratio of Co and Ni in the bifunctional electrocatalyst. This study helps to explore the effect of variable cationic ratio in the cost-effective ternary iron group metal phosphides electrocatalysts to achieve enhanced electrocatalytic performance for water splitting in a wide pH range.

Ruthenium nanodendrites on reduced graphene oxide: an efficient water and 4-nitrophenol reduction catalyst

2021 ◽  
Author(s):  
Barun Kumar Barman ◽  
Bidushi Sarkar ◽  
Ravi Nandan ◽  
Karuna Kar Nanda
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Environmental Remediation ◽  
Water Reduction ◽  
Nitrophenol Reduction ◽  
Reduced Graphene ◽  
Wide Ph Range ◽  
Ph Range

A green and efficient protocol is reported for the elegant design of reduced graphene oxide (rGO)-supported Ru nanodendrites for promotion of electrochemical water reduction in a wide pH range as well as for environmental remediation.

scholarly journals Defect-Rich Heterogeneous MoS2/rGO/NiS Nanocomposite for Efficient pH-Universal Hydrogen Evolution

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 662 ◽  
Author(s):  
Guangsheng Liu ◽  
Kunyapat Thummavichai ◽  
Xuefeng Lv ◽  
Wenting Chen ◽  
Tingjun Lin ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Reduced Graphene ◽  
Heterogeneous Interfaces ◽  
Wide Ph Range ◽  
Ph Range ◽  
A Current ◽  
Poor Stability

Molybdenum disulfide (MoS2) has been universally demonstrated to be an effective electrocatalytic catalyst for hydrogen evolution reaction (HER). However, the low conductivity, few active sites and poor stability of MoS2-based electrocatalysts hinder its hydrogen evolution performance in a wide pH range. The introduction of other metal phases and carbon materials can create rich interfaces and defects to enhance the activity and stability of the catalyst. Herein, a new defect-rich heterogeneous ternary nanocomposite consisted of MoS2, NiS and reduced graphene oxide (rGO) are synthesized using ultrathin αNi(OH)2 nanowires as the nickel source. The MoS2/rGO/NiS-5 of optimal formulation in 0.5 M H2SO4, 1.0 M KOH and 1.0 M PBS only requires 152, 169 and 209 mV of overpotential to achieve a current density of 10 mA cm−2 (denoted as η10), respectively. The excellent HER performance of the MoS2/rGO/NiS-5 electrocatalyst can be ascribed to the synergistic effect of abundant heterogeneous interfaces in MoS2/rGO/NiS, expanded interlayer spacings, and the addition of high conductivity graphene oxide. The method reported here can provide a new idea for catalyst with Ni-Mo heterojunction, pH-universal and inexpensive hydrogen evolution reaction electrocatalyst.

scholarly journals A Laser Reduced Graphene Oxide Grid Electrode for the Voltammetric Determination of Carbaryl

2021 ◽  
Author(s):  
Muhammad Saqib ◽  
Elena V. Dorozhko ◽  
Jiri Barek ◽  
Vlastimil Vyskocil ◽  
Elena Korotkova ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Fruit Juices ◽  
Grid Electrode ◽  
Oxidation Current ◽  
Reduced Graphene ◽  
Electrochemically Active ◽  
One Step ◽  
Ph Range

Laser reduced graphene oxide (LRGO) on a PET substrate was prepared in one-step to obtain the LRGO grid electrode for sensitive carbaryl determination. The grid form results in a grid distribution of different electrochemically active zones affecting the electroactive substance diffusion towards to the electrode surface and increasing the electrochemical sensitivity for carbaryl determination. Carbaryl is electrochemically irreversibly oxidized by the secondary amine moiety of the molecule with the loss of one proton and one electron in the pH range from 5 to 7 by LSV on the LRGO grid electrode with a scan rate of 300 mV/s. Some interference of the juice matrix molecules did not significantly affect the LSV oxidation current of carbaryl on the LRGO grid electrode after adsorptive accumulation without applied potential. The LRGO grid electrode can be used for LSV determination of carbaryl in fruit juices in the concentration range from 0.25 to 128 mg/L with LOD of 0.1 mg/L by. The fabrication of the LRGO grid electrode opens up possibilities for further inexpensive monitoring of carbaryl in other fruit juices and fruits.

scholarly journals A Laser Reduced Graphene Oxide Grid Electrode for the Voltammetric Determination of Carbaryl

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 5050
Author(s):  
Muhammad Saqib ◽  
Elena V. Dorozhko ◽  
Jiri Barek ◽  
Vlastimil Vyskocil ◽  
Elena I. Korotkova ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Fruit Juices ◽  
Grid Electrode ◽  
Oxidation Current ◽  
Reduced Graphene ◽  
Electrochemically Active ◽  
One Step ◽  
Ph Range

Laser-reduced graphene oxide (LRGO) on a polyethylene terephthalate (PET) substrate was prepared in one step to obtain the LRGO grid electrode for sensitive carbaryl determination. The grid form results in a grid distribution of different electrochemically active zones affecting the electroactive substance diffusion towards the electrode surface and increasing the electrochemical sensitivity for carbaryl determination. Carbaryl is electrochemically irreversibly oxidized at the secondary amine moiety of the molecule with the loss of one proton and one electron in the pH range from 5 to 7 by linear scan voltammetry (LSV) on the LRGO grid electrode with a scan rate of 300 mV/s. Some interference of the juice matrix molecules does not significantly affect the LSV oxidation current of carbaryl on the LRGO grid electrode after adsorptive accumulation without applied potential. The LRGO grid electrode can be used for LSV determination of carbaryl in fruit juices in the concentration range from 0.25 to 128 mg/L with LOD of 0.1 mg/L. The fabrication of the LRGO grid electrode opens up possibilities for further inexpensive monitoring of carbaryl in other fruit juices and fruits

Cluster-like molybdenum phosphide anchored on reduced graphene oxide for efficient hydrogen evolution over a broad pH range

2016 ◽  
Vol 52 (61) ◽  
pp. 9530-9533 ◽  
Author(s):  
Haijing Yan ◽  
Yanqing Jiao ◽  
Aiping Wu ◽  
Chungui Tian ◽  
Xiaomeng Zhang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Hydrogen Evolution ◽  
Electrocatalytic Activity ◽  
High Uniformity ◽  
Reduced Graphene ◽  
Molybdenum Phosphide ◽  
Ph Range

Cluster-like MoP particles were anchored on rGO with high uniformity, and exhibit superior electrocatalytic activity towards the HER.

Sign in / Sign up

Export Citation Format

Share Document