A novel approach for the preparation of Ni–CeO₂ composite cathodes with enhanced electrocatalytic activity

Abstract

In this work, supergravity fields were utilized to prepare Ni-CeO 2 composite cathodes from a nickel sulphamate bath containing suspended nano-sized CeO 2 particles. The prepared Ni-CeO 2 composite coatings exhibit a significant enhancement in electrocatalytic activity for the hydrogen evolution reaction (HER) in alkaline solutions. The crystal structure, morphology and chemical compositions of the composite coatings were characterized by XRD, SEM and EDS measurements. It was shown that the prepared Ni-CeO 2 composite coatings displayed a fine grain size and high contents of CeO 2 incorporated into the Ni matrix. The electrochemical activity of the composite cathodes for HER was determined by polarization measurements and electrochemical impedance spectroscopy in 1.0 M NaOH solution. The results indicate that the catalytic activity of the Ni-CeO 2 composite coatings is enhanced significantly, and the highest value of the exchange current density reaches 338.4 mA cm À2 , which is obviously higher than the values previously reported in the literature. Meanwhile, the effects of both the CeO 2 concentration and the intensities of the supergravity fields on the properties of the Ni-CeO 2 coatings are investigated.

Ni–reduced graphene oxide composite cathodes with new hierarchical morphologies for electrocatalytic hydrogen generation in alkaline media

“…The value of (R ct + R p ) could also explain electrocatalytic activity for HER which have studied in our published papers. 18,20 Considering electrochemical active surface area plays a crucial role in improving electrocatalytic activity for HER, the surface roughness R f is calculated by comparing the double layer capacitance C dl value with 20 mF cm À2 for smooth electrode surface (R f ¼ C dl /20). 44 The double layer capacitance C dl of the electrode is obtained by using the equation from Brug et al 10,[46][47][48][49] As calculated in Table 3, it can be found that the R f values of Ni-rGO composite samples increase remarkably compared with the pure Ni electrode, and obtain the highest value of 836 for 0.7 g L À1 GO in bath solution.…”

“…Among the non-noble metals, Ni and Ni-based electrode materials have been widely considered as promising electrocatalytic materials due to their comparatively large electrocatalytic activity and good stability for HER in alkaline solutions. 8 Two main approaches including alloying Ni with some other metals or non-metals [9][10][11][12][13][14][15][16] and compositing Ni with active nano-sized particles [17][18][19][20][21][22] have been taken to enhance the intrinsic activity and/or increase the real surface area of electrode materials for HER.…”

“…30 Recently, we have found that the micro mixing, mass transfer process and bubble separation rate during composite electrodeposition could be markedly promoted by introducing supergravity eld, giving rise to a dramatical change both in the microstructure and the morphology of materials. 20,22,31 Based on the results, this research aims at combining the supergravity eld with the a Hebei Key Laboratory of Applied Chemistry, College of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao 066004, China. E-mail: shaoguangjie@ysu.edu.cn; Fax: +86 335 8061569; Tel: +86 335 8061569 electrodeposition process to acquire Ni-rGO composite cathode with prominently changed morphology and structure for HER.…”

The Effects of CeO2 Nanorods and CeO2 Nanoflakes on Ni–S Alloys in Hydrogen Evolution Reactions in Alkaline Solutions

“…Li et al studied the effects of different magnitudes of CeO 2 on Ni-S and Ni-Zn coatings in the catalytic activities of HERs [23,24]. Our team studied the catalytic activities of Ni-CeO 2 and Ni-S/CeO 2 composites in hydrogen evolution [27,28]. In this paper, we prepared different morphologies of CeO 2 and studied the impacts of different CeO 2 morphologies on Ni-S alloys in HERs.…”

An Electrocatalyst for a Hydrogen Evolution Reaction in an Alkaline Medium: Three‐Dimensional Graphene Supported CeO2 Hollow Microspheres

“…Among them, CeO 2 has been extensively studied for catalytic application owing to its high oxygen transfer ability. Considering the morphology and surface structure‐dependent catalytic properties of CeO 2 , the size and shape‐controlled synthesis of CeO 2 micro‐/nanocrystals has been a matter of intense research . However, owing to the existence of a highly exposed surface, the CeO 2 nanoparticles tend to aggregate and thus lower the catalytic performance.…”