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 Effect of Ag2S Nanocrystals/Reduced Graphene Oxide Interface on Hydrogen Evolution Reaction

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 948
Author(s):  
Chen Zhao ◽  
Zhi Yu ◽  
Jun Xing ◽  
Yuting Zou ◽  
Huiwen Liu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Fossil Fuels ◽  
Composite Catalyst ◽  
Oxide Interface ◽  
Electrochemical Catalyst ◽  
Reduced Graphene

The development of efficient electrocatalyst to produce molecular hydrogen from water is receiving considerable attention, in an effort to decrease our reliance on fossil fuels. The prevention of the aggregation of active sites during material synthesis, in order to increase charge transport properties of electrocatalysts, is needed. We have designed, synthesized, and studied a Ag2S/reduced graphene oxide (rGO) electrochemical catalyst (for hydrogen evolution) from water. The Ag2S nanocrystals were synthesized by the solvothermal method in which the rGO was added. The addition of the rGO resulted in the formation of smaller Ag2S nanocrystals, which consequently increased the electrical conductivity of the composite catalyst. The composite catalyst showed a higher electrochemical catalytic activity than the one with an absence of rGO. At a current density of 10 mA/cm2, a low overpotential of 120 mV was obtained. A Tafel slope of 49.1 mV/dec suggests a Volmer–Herovsky mechanism for the composite catalyst. These results may provide a novel strategy for developing hydrogen evolution reaction (HER) electrocatalysts, via the combining of a nano-semiconductor catalyst with a 2D material.

scholarly journals The effect of surface modification by reduced graphene oxide on the electrocatalytic activity of nickel towards the hydrogen evolution reaction

2015 ◽  
Vol 17 (40) ◽  
pp. 26864-26874 ◽  
Author(s):  
Debabrata Chanda ◽  
Jaromír Hnát ◽  
Ana S. Dobrota ◽  
Igor A. Pašti ◽  
Martin Paidar ◽  
...  
Keyword(s):  
Surface Modification ◽  
Graphene Oxide ◽  
Dft Calculations ◽  
Reduced Graphene Oxide ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Electrocatalytic Activity ◽  
Active Sites ◽  
Reduced Graphene ◽  
Effect Of Surface

The RGO-modified Ni electrode exhibited outstanding activity towards HER. DFT calculations indicate that H atoms, formed upon H2O discharge on Ni, spill onto the RGO, enabling continuous clearance of Ni-active sites.

scholarly journals One-step hydrothermal synthesis of NiS/MoS2-rGO composites and their application as catalysts for hydrogen evolution reaction

2016 ◽  
Vol 09 (05) ◽  
pp. 1650058 ◽  
Author(s):  
Huaping Wu ◽  
Ye Qiu ◽  
Junma Zhang ◽  
Guozhong Chai ◽  
Congda Lu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Hydrothermal Synthesis ◽  
Hydrothermal Method ◽  
Reduced Graphene Oxide ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Layer Structures ◽  
Reduced Graphene ◽  
One Step

The composites of sulphide and reduced graphene oxide (NiS/MoS2-rGO) were synthesized through a facile solvent-assisted hydrothermal method. The introduction of NiS was paramount not only in enhancing the conductivity of whole catalysts but also in modulating the layer structures of MoS2 with additional active sites. Moreover, the NiS and rGO functioned together in controlling the morphology of as-prepared composites, resulting in uniformly distributed NiS/MoS2 nanosheets perpendicular to rGO scaffold. This further contributed to the excellent hydrogen evolution performance of the composites with a small onset overpotential of 80[Formula: see text]mV and Tafel slope as low as 65[Formula: see text]mV/decade.

MOFs-derived ruthenium-doped amorphous molybdenum dioxide hybrid for highly efficient hydrogen evolution reaction in alkaline media

2021 ◽  
Author(s):  
Ji-Yuan Han ◽  
Sheng-Hao Cai ◽  
Ji-Yu Zhu ◽  
Shuang Yang ◽  
Ji-Sen Li
Keyword(s):  
Graphene Oxide ◽  
Synergistic Effect ◽  
Reduced Graphene Oxide ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Alkaline Media ◽  
Molybdenum Dioxide ◽  
Highly Efficient ◽  
Reduced Graphene

Ruthenium-doped amorphous molybdenum dioxide coupled with reduced graphene oxide hybrid (Ru-MoO2@PC/rGO) is synthesized using POMOF/GO as precursor. Benefitting from the synergistic effect of numerous exposed active sites, Ru dopants, and...

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