Rational design of atomically dispersed nickel active sites in β-Mo2C for the hydrogen evolution reaction at all pH values

2018 ◽  
Vol 54 (71) ◽  
pp. 9901-9904 ◽  
Author(s):  
Ting Ouyang ◽  
An-Na Chen ◽  
Zhen-Zhao He ◽  
Zhao-Qing Liu ◽  
Yexiang Tong

Atomically dispersed Ni in β-Mo2C (Ni/β-Mo2C) is designed as an efficient catalyst for the HER at all pH values. The remarkable electrochemical properties of Ni/β-Mo2C are mainly attributed to the synergistic effect between atomically dispersed Ni species and β-Mo2C.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Panlong Zhai ◽  
Mingyue Xia ◽  
Yunzhen Wu ◽  
Guanghui Zhang ◽  
Junfeng Gao ◽  
...  

AbstractRational design of single atom catalyst is critical for efficient sustainable energy conversion. However, the atomic-level control of active sites is essential for electrocatalytic materials in alkaline electrolyte. Moreover, well-defined surface structures lead to in-depth understanding of catalytic mechanisms. Herein, we report a single-atomic-site ruthenium stabilized on defective nickel-iron layered double hydroxide nanosheets (Ru1/D-NiFe LDH). Under precise regulation of local coordination environments of catalytically active sites and the existence of the defects, Ru1/D-NiFe LDH delivers an ultralow overpotential of 18 mV at 10 mA cm−2 for hydrogen evolution reaction, surpassing the commercial Pt/C catalyst. Density functional theory calculations reveal that Ru1/D-NiFe LDH optimizes the adsorption energies of intermediates for hydrogen evolution reaction and promotes the O–O coupling at a Ru–O active site for oxygen evolution reaction. The Ru1/D-NiFe LDH as an ideal model reveals superior water splitting performance with potential for the development of promising water-alkali electrocatalysts.


Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1520 ◽  
Author(s):  
Dan Li ◽  
Yang Li ◽  
Bowei Zhang ◽  
Yu Lui ◽  
Sivaprasad Mooni ◽  
...  

Pt as a chemical inert metal has been widely applied as the counter electrode in various electrochemical measurements. However, it can also be dissolved and redeposit to the working electrode under certain electrochemical circumstances. Herein we demonstrated a cyclic voltammetry (CV) cycling method to synthesize a catalyst comprising inserted Pt nanoparticles into MoS2 nanoflake stack structures on stainless steel mesh (SSM). The binder-free composite structure exhibits significantly enhanced hydrogen evolution reaction (HER) catalytic activity with an overpotentials of 87 mV at 10 mA cm−2. The deposited Pt nanoparticles significantly enhance the catalytic activity through changing the structure of MoS2 and increasing the amount of active sites. This work provides a new way forward for rational design of the nano-electrocatalysts.


2020 ◽  
Vol 8 (46) ◽  
pp. 24710-24717
Author(s):  
Haigang Liu ◽  
Zhe Hu ◽  
Qinglei Liu ◽  
Peng Sun ◽  
Yongfei Wang ◽  
...  

A catalyst consisting of single-atom Ru sites supported on an N-MXene (Ti3C2Tx) was developed for pH-universal hydrogen generation based on theoretical predictions, whose performances are comparable to and better than those of Pt/C.


2021 ◽  
Author(s):  
Ji-Yuan Han ◽  
Sheng-Hao Cai ◽  
Ji-Yu Zhu ◽  
Shuang Yang ◽  
Ji-Sen Li

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...


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Tuan Van Nguyen ◽  
Ha Huu Do ◽  
Mahider Tekalgne ◽  
Quyet Van Le ◽  
Thang Phan Nguyen ◽  
...  

AbstractTransition metal dichalcogenides (TMDs), transition metal carbides (TMCs), and transition metal oxides (TMOs) have been widely investigated for electrocatalytic applications owing to their abundant active sites, high stability, good conductivity, and various other fascinating properties. Therefore, the synthesis of composites of TMDs, TMCs, and TMOs is a new avenue for the preparation of efficient electrocatalysts. Herein, we propose a novel low-cost and facile method to prepare TMD–TMC–TMO nano-hollow spheres (WS2–WC–WO3 NH) as an efficient catalyst for the hydrogen evolution reaction (HER). The crystallinity, morphology, chemical bonding, and composition of the composite material were comprehensively investigated using X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, and X-ray photoelectron spectroscopy. The results confirmed the successful synthesis of the WS2–WC–WO3 NH spheres. Interestingly, the presence of nitrogen significantly enhanced the electrical conductivity of the hybrid material, facilitating electron transfer during the catalytic process. As a result, the WS2–WC–WO3 NH hybrid exhibited better HER performance than the pure WS2 nanoflowers, which can be attributed to the synergistic effect of the W–S, W–C, and W–O bonding in the composite. Remarkably, the Tafel slope of the WS2–WC–WO3 NH spheres was 59 mV dec−1, which is significantly lower than that of the pure WS2 NFs (82 mV dec−1). The results also confirmed the unprecedented stability and superior electrocatalytic performance of the WS2–WC–WO3 NH spheres toward the HER, which opens new avenues for the preparation of low-cost and highly effective materials for energy conversion and storage applications.


Author(s):  
Lifang Chen ◽  
Rizwan Ur Rehman Sagar ◽  
Jun Chen ◽  
Juan Liu ◽  
Sehrish Aslam ◽  
...  

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 662 ◽  
Author(s):  
Guangsheng Liu ◽  
Kunyapat Thummavichai ◽  
Xuefeng Lv ◽  
Wenting Chen ◽  
Tingjun Lin ◽  
...  

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.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Yingjie Yang ◽  
Yanhui Yu ◽  
Jing Li ◽  
Qingrong Chen ◽  
Yanlian Du ◽  
...  

AbstractThe investigation of highly effective, durable, and cost-effective electrocatalysts for the hydrogen evolution reaction (HER) is a prerequisite for the upcoming hydrogen energy society. To establish a new hydrogen energy system and gradually replace the traditional fossil-based energy, electrochemical water-splitting is considered the most promising, environmentally friendly, and efficient way to produce pure hydrogen. Compared with the commonly used platinum (Pt)-based catalysts, ruthenium (Ru) is expected to be a good alternative because of its similar hydrogen bonding energy, lower water decomposition barrier, and considerably lower price. Analyzing and revealing the HER mechanisms, as well as identifying a rational design of Ru-based HER catalysts with desirable activity and stability is indispensable. In this review, the research progress on HER electrocatalysts and the relevant describing parameters for HER performance are briefly introduced. Moreover, four major strategies to improve the performance of Ru-based electrocatalysts, including electronic effect modulation, support engineering, structure design, and maximum utilization (single atom) are discussed. Finally, the challenges, solutions and prospects are highlighted to prompt the practical applications of Ru-based electrocatalysts for HER.


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