One-step integration of amorphous RuBx and crystalline Ru nanoparticles into B/N-doped porous carbon polyhedrals for robust electrocatalytic activity towards HER in both acidic and basic media

Author(s):  
Jie Tang ◽  
Biao Wang ◽  
Yanzheng Zhang ◽  
Xiao-Hua Zhang ◽  
Qinghui Shen ◽  
...  

As a research hot in hydrogen production by water electrolysis, exploring efficient, stable and low-cost hydrogen evolution catalysts is highly desirable and significant for the development of large-scale water electrolysis,...

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Karolina Kordek-Khalil ◽  
Dawid Janas ◽  
Piotr Rutkowski

AbstractLarge-scale sustainable hydrogen production by water electrolysis requires a highly active yet low-cost hydrogen evolution reaction (HER) electrocatalyst. Conductive carbon nanomaterials with high surface areas are promising candidates for this purpose. In this contribution, single-walled carbon nanotubes (SWCNTs) are assembled into free-standing films and directly used as HER electrodes. During the initial 20 h of electrocatalytic performance in galvanostatic conditions, the films undergo activation, which results in a gradual overpotential decrease to the value of 225 mV. Transient physicochemical properties of the films at various activation stages are characterized to reveal the material features responsible for the activity boost. Results indicate that partial oxidation of iron nanoparticles encapsulated in SWCNTs is the major contributor to the activity enhancement. Furthermore, besides high activity, the material, composed of only earth-abundant elements, possesses exceptional performance stability, with no activity loss for 200 h of galvanostatic performance at − 10 mA cm−2. In conclusion, the work presents the strategy of engineering a highly active HER electrode composed of widely available elements and provides new insights into the origins of electrocatalytic performance of SWCNT-based materials in alkaline HER.


2021 ◽  
Author(s):  
Yaoxia Yang ◽  
Xuqin An ◽  
Mi Kang ◽  
Fengyao Guo ◽  
Lan Zhang ◽  
...  

The construction of excellent performance electrocatalysts for hydrogen evolution reaction (HER) with low-cost and economical strategy was still struggling with an enormous challenge in electrochemical water splitting. In this paper,...


2021 ◽  
Author(s):  
Zihao Liu ◽  
Shifeng Li ◽  
Fangfang Wang ◽  
Mingxia Li ◽  
Yonghong Ni

FeNi-layered double hydroxide (LDH) is thought to be an excellent electrocatalyst for oxygen evolution reaction (OER), but it always shows extremely poor electrocatalytic activity toward hydrogen evolution reaction (HER) in...


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shan Wang ◽  
Aolin Lu ◽  
Chuan-Jian Zhong

AbstractAs a promising substitute for fossil fuels, hydrogen has emerged as a clean and renewable energy. A key challenge is the efficient production of hydrogen to meet the commercial-scale demand of hydrogen. Water splitting electrolysis is a promising pathway to achieve the efficient hydrogen production in terms of energy conversion and storage in which catalysis or electrocatalysis plays a critical role. The development of active, stable, and low-cost catalysts or electrocatalysts is an essential prerequisite for achieving the desired electrocatalytic hydrogen production from water splitting for practical use, which constitutes the central focus of this review. It will start with an introduction of the water splitting performance evaluation of various electrocatalysts in terms of activity, stability, and efficiency. This will be followed by outlining current knowledge on the two half-cell reactions, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), in terms of reaction mechanisms in alkaline and acidic media. Recent advances in the design and preparation of nanostructured noble-metal and non-noble metal-based electrocatalysts will be discussed. New strategies and insights in exploring the synergistic structure, morphology, composition, and active sites of the nanostructured electrocatalysts for increasing the electrocatalytic activity and stability in HER and OER will be highlighted. Finally, future challenges and perspectives in the design of active and robust electrocatalysts for HER and OER towards efficient production of hydrogen from water splitting electrolysis will also be outlined.


2021 ◽  
Vol 13 (14) ◽  
pp. 7804
Author(s):  
Christoph Falter ◽  
Andreas Sizmann

Hydrogen produced from renewable energy has the potential to decarbonize parts of the transport sector and many other industries. For a sustainable replacement of fossil energy carriers, both the environmental and economic performance of its production are important. Here, the solar thermochemical hydrogen pathway is characterized with a techno-economic and life-cycle analysis. Assuming a further increase of conversion efficiency and a reduction of investment costs, it is found that hydrogen can be produced in the United States of America at costs of 2.1–3.2 EUR/kg (2.4–3.6 USD/kg) at specific greenhouse gas emissions of 1.4 kg CO2-eq/kg. A geographical potential analysis shows that a maximum of 8.4 × 1011 kg per year can be produced, which corresponds to about twelve times the current global and about 80 times the current US hydrogen production. The best locations are found in the Southwest of the US, which have a high solar irradiation and short distances to the sea, which is beneficial for access to desalinated water. Unlike for petrochemical products, the transport of hydrogen could potentially present an obstacle in terms of cost and emissions under unfavorable circumstances. Given a large-scale deployment, low-cost transport seems, however, feasible.


Author(s):  
Xuejun Zhai ◽  
Qingping Yu ◽  
Guishan Liu ◽  
Junlu Bi ◽  
Yu Zhang ◽  
...  

Hydrogen evolution reaction (HER) based on water electrolysis is promising for renewable hydrogen production. Limited by sluggish anodic oxygen evolution reaction (OER), rational fabrication of efficient catalyst for HER coupled...


Author(s):  
Jianwen Liu ◽  
Wangping Wu ◽  
Xiang Wang

Developing novel hydrogen evolution reaction (HER) catalysts with high activity, high stability and low cost is of great importance for the applications of hydrogen energy. In this work, iridium-nickel (Ir-Ni) thin films were electrodeposited on a copper foam as electrocatalyst for HER, and electrodeposition mechanism of Ir-Ni film was studied. The morphology and chemical composition of thin films were determined by scanning electron microscopy and energy-dispersive spectroscopy, respectively. The electrocatalytic performances of the films were estimated by linear sweep voltammograms, electrochemical impedance spectroscopy and cyclic voltammetry. The results show that Ir-Ni thin films were attached to the substrate of porous structure and hollow topography. The deposition of Ni was preferable in the electrolyte without the addition of additives, and Ir-Ni thin film was alloyed, resulting in high deposition rate for Ir42Ni58 thin film, and subsequently an increase of Ir content in the thin films of Ir80Ni20 and Ir88Ni12. Ir-Ni thin films with Tafel slopes of 40-49 mV·dec-1 exhibited highly efficient electrocatalytic activity for HER. The electrocatalytic activity of Ir-Ni thin films showed a loading dependence. As the solution temperature raised from 20 oC to 60 oC, the hydrogen evolution performance of Ir-Ni thin films improved. The apparent activation energy value of Ir88Ni12 film was 7.1 kJ·mol-1. Long-term hydrogen evolution tests exhibited excellent electrocatalystic stability in alkaline solution.


Author(s):  
Hanwen Xu ◽  
Jiawei Zhu ◽  
Pengyan Wang ◽  
Ding Chen ◽  
Chengtian Zhang ◽  
...  

Rational design and construction of high-efficiency bifunctional catalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is crucial for large-scale hydrogen production by water splitting. Herein, by a...


2020 ◽  
Vol 8 (8) ◽  
pp. 4376-4385 ◽  
Author(s):  
Youyi Lei ◽  
Xinmiao Liang ◽  
Li Yang ◽  
Ping Jiang ◽  
Zhenyu Lei ◽  
...  

Low-cost hierarchical porous carbon materials with a controllable structure for supercapacitors and lithium selenium batteries.


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