Synergistic Effects of Tungsten Doping and Sulfur Vacancies in MoS2 on Enhancement of Hydrogen Evolution

Author(s):  
Qiuchen Xu ◽  
Yuefeng Zhang ◽  
Yiteng Zheng ◽  
Yanxia Liu ◽  
Zhangmin Tian ◽  
...  
Hydrogen ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 11-21
Author(s):  
Youyi Sun ◽  
Alexey Y. Ganin

Metal alloys have become a ubiquitous choice as catalysts for electrochemical hydrogen evolution in alkaline media. However, scarce and expensive Pt remains the key electrocatalyst in acidic electrolytes, making the search for earth-abundant and cheaper alternatives important. Herein, we present a facile and efficient synthetic route towards polycrystalline Co3Mo and Co7Mo6 alloys. The single-phased nature of the alloys is confirmed by X-ray diffraction and electron microscopy. When electrochemically tested, they achieve competitively low overpotentials of 115 mV (Co3Mo) and 160 mV (Co7Mo6) at 10 mA cm−2 in 0.5 M H2SO4, and 120 mV (Co3Mo) and 160 mV (Co7Mo6) at 10 mA cm−2 in 1 M KOH. Both alloys outperform Co and Mo metals, which showed significantly higher overpotentials and lower current densities when tested under identical conditions, confirming the synergistic effect of the alloying. However, the low overpotential in Co3Mo comes at the price of stability. It rapidly becomes inactive when tested under applied potential bias. On the other hand, Co7Mo6 retains the current density over time without evidence of current decay. The findings demonstrate that even in free-standing form and without nanostructuring, polycrystalline bimetallic electrocatalysts could challenge the dominance of Pt in acidic media if ways for improving their stability were found.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Ruopeng Li ◽  
Hao Xu ◽  
Peixia Yang ◽  
Dan Wang ◽  
Yun Li ◽  
...  

AbstractTo achieve high efficiency of water electrolysis to produce hydrogen (H2), developing non-noble metal-based catalysts with considerable performance have been considered as a crucial strategy, which is correlated with both the interphase properties and multi-metal synergistic effects. Herein, as a proof of concept, a delicate NiCo(OH)x-CoyW catalyst with a bush-like heterostructure was realized via gas-template-assisted electrodeposition, followed by an electrochemical etching-growth process, which ensured a high active area and fast gas release kinetics for a superior hydrogen evolution reaction, with an overpotential of 21 and 139 mV at 10 and 500 mA cm−2, respectively. Physical and electrochemical analyses demonstrated that the synergistic effect of the NiCo(OH)x/CoyW heterogeneous interface resulted in favorable electron redistribution and faster electron transfer efficiency. The amorphous NiCo(OH)x strengthened the water dissociation step, and metal phase of CoW provided sufficient sites for moderate H immediate adsorption/H2 desorption. In addition, NiCo(OH)x-CoyW exhibited desirable urea oxidation reaction activity for matching H2 generation with a low voltage of 1.51 V at 50 mA cm−2. More importantly, the synthesis and testing of the NiCo(OH)x-CoyW catalyst in this study were all solar-powered, suggesting a promising environmentally friendly process for practical applications.


2019 ◽  
Vol 7 (28) ◽  
pp. 17046-17052 ◽  
Author(s):  
Sanjib Baran Roy ◽  
Sahng-Kyoon Jerng ◽  
Kamran Akbar ◽  
Jae Ho Jeon ◽  
Linh Truong ◽  
...  

Cobalt-encapsulating vertical graphene nano-hills exhibit high hydrogen evolution reaction activity because of the synergistic effects of curvature and doping.


Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2233 ◽  
Author(s):  
Haocong Dong ◽  
Junzhu Li ◽  
Mingguang Chen ◽  
Hongwei Wang ◽  
Xiaochuan Jiang ◽  
...  

High-throughput production of highly efficient photocatalysts for hydrogen evolution remains a considerable challenge for materials scientists. Here, we produced extremely uniform high-quality graphene and molybdenum disulfide (MoS2) nanoplatelets through the electrochemical-assisted liquid-phase exfoliation, out of which we subsequently fabricated MoS2/graphene van der Waals heterostructures. Ultimately, zinc oxide (ZnO) nanoparticles were deposited into these two-dimensional heterostructures to produce an artificial ZnO/MoS2/graphene nanocomposite. This new composite experimentally exhibited an excellent photocatalytic efficiency in hydrogen evolution under the sunlight illumination ( λ > 400   n m ), owing to the extremely high electron mobilities in graphene nanoplatelets and the significant visible-light absorptions of MoS2. Moreover, due to the synergistic effects in MoS2 and graphene, the lifetime of excited carriers increased dramatically, which considerably improved the photocatalytic efficiency of the ZnO/MoS2/graphene heterostructure. We conclude that the novel artificial heterostructure presented here shows great potential for the high-efficient photocatalytic hydrogen generation and the high throughput production of visible-light photocatalysts for industrial applications.


2019 ◽  
Vol 12 (2) ◽  
pp. 2207-2215 ◽  
Author(s):  
Daily Rodríguez-Padrón ◽  
Alain R. Puente-Santiago ◽  
Manuel Cano ◽  
Alvaro Caballero ◽  
Mario J. Muñoz-Batista ◽  
...  

2020 ◽  
Vol 4 (10) ◽  
pp. 5247-5253
Author(s):  
HyoWon Kim ◽  
Yongju Lee ◽  
DongHoon Song ◽  
YongKeun Kwon ◽  
Eom-Ji Kim ◽  
...  

HER-active Cu3P/N-doped carbon is inspired by the role of PAN in Li-ion batteries, and non-toxic one step synthesis includes phosphorization of Cu and cyclization of PAN. The synergistic effects and mechanical integrity relate to N-doped carbon.


2019 ◽  
Vol 7 (42) ◽  
pp. 24328-24336 ◽  
Author(s):  
Yao Wang ◽  
Hongying Zhuo ◽  
Xin Zhang ◽  
Yunrui Li ◽  
Juntao Yang ◽  
...  

Ultralong jagged PtMo–S nanowires with rich “interfacial active sites” were fabricated by using S as the “active auxiliary” to demonstrate the enhanced catalytic HER performance triggered by the electronic and synergistic effects of PtMo/MoSx.


2019 ◽  
Vol 3 (8) ◽  
pp. 2100-2110 ◽  
Author(s):  
Subramaniam Jayabal ◽  
Govindarajan Saranya ◽  
Yongqiang Liu ◽  
Dongsheng Geng ◽  
Xiangbo Meng

Synergistic effects from interfacial engineering of 1T-MoS2 and CNTs endow composites with higher activity and stability towards HER.


2015 ◽  
Vol 3 (47) ◽  
pp. 24128-24138 ◽  
Author(s):  
Guowei Huang ◽  
Hao Liu ◽  
Shengping Wang ◽  
Xi Yang ◽  
Binhong Liu ◽  
...  

Three-dimensional interlayer-expanded WS2/3DG architecture exhibits enhanced electrochemical properties for lithium storage and hydrogen evolution due to synergistic effects between the components.


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