scholarly journals One-Pot Synthesis of W2C/WS2 Hybrid Nanostructures for Improved Hydrogen Evolution Reactions and Supercapacitors

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1597 ◽  
Author(s):  
Sajjad Hussain ◽  
Iqra Rabani ◽  
Dhanasekaran Vikraman ◽  
Asad Feroze ◽  
Muhammad Ali ◽  
...  

Tungsten sulfide (WS2) and tungsten carbide (W2C) are materialized as the auspicious candidates for various electrochemical applications, owing to their plentiful active edge sites and better conductivity. In this work, the integration of W2C and WS2 was performed by using a simple chemical reaction to form W2C/WS2 hybrid as a proficient electrode for hydrogen evolution and supercapacitors. For the first time, a W2C/WS2 hybrid was engaged as a supercapacitor electrode and explored an incredible specific capacitance of ~1018 F g−1 at 1 A g−1 with the outstanding robustness. Furthermore, the constructed symmetric supercapacitor using W2C/WS2 possessed an energy density of 45.5 Wh kg−1 at 0.5 kW kg−1 power density. For hydrogen evolution, the W2C/WS2 hybrid produced the low overpotentials of 133 and 105 mV at 10 mA cm−2 with the small Tafel slopes of 70 and 84 mV dec−1 in acidic and alkaline media, respectively, proving their outstanding interfaced electrocatalytic characteristics. The engineered W2C/WS2-based electrode offered the high-performance for electrochemical energy applications.

Nukleonika ◽  
2017 ◽  
Vol 62 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Ahmed Ali Basfar ◽  
Majid Muneer ◽  
Omar Ahmed Alsager

Abstract Chlorophenols are compounds with high toxicity, poor biodegradability, and carcinogenic and recalcitrant properties. This work studies, for the first time, the destruction and detoxification of 2-chlorophenol (2-CP) in water using 60Co gamma radiation under different conditions including varied radiation doses, addition of hydrogen peroxide (H2O2), and varied pH values. High-performance liquid chromatography (HPLC) and ion chromatography (IC) confirmed a successful degradation of 2-CP to primarily yield phenol molecules and chloride anions. A radiation dose as low as 25 kGy achieved approximately 90% removal of 50–150 ppm of 2-CP in neutral water. However, the addition of a strong oxidizer such as H2O2 to 2-CP solutions reduced the required dose to achieve 90% removal to at least 1.3-fold. The reduction in radiation doses was also observed in acidic and alkaline media, reducing the required doses of 90% removal to at least 0.4-fold. It was imperative to study the toxicity levels of the oxidation by-products to provide directions for the potential applicability of this technology in water treatment. Toxicology Microtox® bioassay indicated a significant reduction in the toxicity of the degradation by-products and the detoxification was further enhanced by the addition of H2O2 and changing the pH to more acidic or alkaline conditions. These findings will contribute to the knowledge of the removal and detoxification of such challenging environmental contaminant and could be potentially applied to other biologically resistant compounds.


2021 ◽  
Vol 18 (2) ◽  
pp. 206-216
Author(s):  
Vimukthi Jayaweera ◽  
W.L.N.C. Liyanage ◽  
R.C.L. De Silva ◽  
S.R.D. Rosa ◽  
Iresha R. M. Kottegoda

A novel symmetric supercapacitor electrode material, rGO-SnO2-polyaniline nanocomposite,was synthesized using graphite oxide, SnCl2.2H2O, and pure Aniline as precursors in a scalable and straightforward one-pot process. Analysis revealed that the rGO-SnO2-polyaniline composite had been successfully synthesized. When the two-electrode supercapacitor was assembled using 1M H2SO4, it showed an outstanding specific gravimetric capacitance of 524.2 F/g at a 5 mV/s scan rate. To the best of our knowledge, such a higher value for a two-electrode specific capacitance for a supercapacitor was never reported.Furthermore, even at a high current density of 1 A/g, the material disclosed an outstanding charge-discharge characteristic. Thus, the rGO-SnO2-polyaniline nanocomposite couldalso be used as an electrode for commercial supercapacitors.


2021 ◽  
Vol 9 (5) ◽  
pp. 1994-2002
Author(s):  
Jie Sun ◽  
Jianmin Lu ◽  
Cunping Huang ◽  
Qiang Wu ◽  
Ligang Xia ◽  
...  

2019 ◽  
Vol 12 (01) ◽  
pp. 1850089
Author(s):  
Hou Lin Yu ◽  
Wenliang Shi ◽  
Shuaishuai Li ◽  
Junma Zhang ◽  
Xiaobo Zhang ◽  
...  

A facile, one-pot solvent-mediated hydrothermal process was adopted to prepare nickel sulfide nanoparticles decorated on reduced graphene oxide (NixSy/rGO) as electrocatalysts for hydrogen evolution reaction (HER). The designed solvent (ethylene glycol and deionized water) played a decisive role in controlling both crystalline phase and morphology of NixSy/rGO composites, leading to pure [Formula: see text]-NiS nanoparticles uniformly distributed on rGO sheets under suitable volume ratio of ethylene glycol and deionized water (2:1). The optimized [Formula: see text]-NiS/rGO showed prominent HER catalytic performance with a rather small Tafel slope of 93[Formula: see text]mV/decade and prominent current density of 10[Formula: see text]mA/cm2 at the overpotential of 177[Formula: see text]mV in alkaline environments when compared to pristine [Formula: see text]-NiS and NiS2/rGO catalysts. The excellent catalytic performance and long-term durability even after 8000 cycles confirmed the potential of [Formula: see text]-NiS/rGO composites as efficient electrocatalysts for HER in the alkaline media.


RSC Advances ◽  
2014 ◽  
Vol 4 (66) ◽  
pp. 34739-34750 ◽  
Author(s):  
Alfin Kurniawan ◽  
L. K. Ong ◽  
Fredi Kurniawan ◽  
C. X. Lin ◽  
Felycia E. Soetaredjo ◽  
...  

For the first time, porous carbon microfibers co-doped with N/P/K were synthesized from cane molasses by combination of electrospinning and carbonization techniques and its electrochemical application to electrode materials for supercapacitors was investigated.


RSC Advances ◽  
2016 ◽  
Vol 6 (9) ◽  
pp. 7370-7377 ◽  
Author(s):  
Yang Zhao ◽  
Shuo Wang ◽  
Chunyan Li ◽  
Xianbo Yu ◽  
Chunling Zhu ◽  
...  

MoP/N,P dual-doped carbon nanotube composite exhibited excellent activity and long-term stability toward HER both in acidic and alkaline media, superior to most of catalysts reported previously.


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