Pulsed laser deposition of porous N-carbon supported cobalt (oxide) thin films for highly efficient oxygen evolution

Abstract

Identifying efficient non-precious metal catalysts for oxygen evolution reaction (OER) remains a great challenge. Here we report robust cobalt (oxide) nanoparticles deposited on porous nitrogen-doped carbon (N-carbon) film prepared by pulsed laser deposition under a reactive background gas which exhibit highly efficient OER performance with low overpotential and high stability.The global energy crisis has prompted intense research into the development of various types of sustainable energy conversion and storage systems.1 Splitting water is widely considered to be a critical step toward efficient renewable energy production, storage and usage. One of the major hurdles in making water electrolysis commercially more viable is the low efficiency of the anodic oxygen evolution reaction (OER) and the high cost of conventional OER catalysts such as IrO 2 and RuO 2 .2 Inexpensive and durable "noble metal-free" electrocatalysts such as non-precious metal and metal-free nanostructures, as well as their hybrids, have received much attention recently.3 Among different non-precious metals, cobalt-based materials are promising OER catalysts, however, the easy accumulation and low conductivity of pure cobalt oxides decreases the available active sites and limits charge transport during the oxidation process. 4 On the other hand, various carbon-based materials feature unique advantages due to their tunable molecular structures, abundance, and strong tolerance to acid/alkaline environments. The interplay between carbon and cobalt oxide nanoparticles can modify the overall physicochemical and electronic structures which make the resultant composites highly competitive to traditional cobalt-based electrocatalysts. 5Despite recent progress in developing non-precious metal (specifically cobalt) based hybrid materials, new OER electrocatalysts with low overpotentials and long-term stability are still needed. To overcome these challenges, synthesis techniques are required which ensure high control and tunability of morphology, structure and composition of multi-component materials. Physical vapour deposition (PVD) techniques allow high purity and control in the fabrication of coatings and thin films. In this context, pulsed laser deposition (PLD) is particularly versatile in the tuning of properties of deposited materials 6 which is based on ablating a target material by laser pulses to produce plasma of ejected species that can be deposited onto a substrate. The control of the ablation process permits the tuning of the growth mode and properties of the deposited films over a wide range.

MO‐Co@N‐Doped Carbon (M = Zn or Co): Vital Roles of Inactive Zn and Highly Efficient Activity toward Oxygen Reduction/Evolution Reactions for Rechargeable Zn–Air Battery

“…[9] Recent reports also demonstrate that N-related species are active for OER. [5,[48][49][50][51][52][53] In this work, the catalysts include both N-and metal-based species. [5,[48][49][50][51][52][53] In this work, the catalysts include both N-and metal-based species.…”

“…[46,47] In addition, transition metal species with variable oxidation states are responsible for ORR and/or OER activities. [5,[48][49][50][51][52][53] In this work, the catalysts include both N-and metal-based species. N-based species contain N 1 -pyrridinic N, M-N x , N 2 -pyrrolic N, and N 3 -quaternary N (Figure 1f), while metal-based species primarily include Co (Co 0 ), CoO (Co 2+ ), and ZnO (Figure 2), as well as the surface Co 3+ (Figure 1e).…”

Phosphine-free avenue to Co2P nanoparticle encapsulated N,P co-doped CNTs: a novel non-enzymatic glucose sensor and an efficient electrocatalyst for oxygen evolution reaction

“…Thus a tremendous effort is now being devoted to the development of highly active and stable low-cost OER electrocatalysts wherein Co-based catalysts are found to perform extremely well. [19][20][21][22] Recently, dicobalt phosphide (Co 2 P) has received increased attention due to their catalytic and magnetic properties as well as being a promising electrode material. [23][24][25] However, most of the existing protocols to synthesize Co 2 P nanoparticles involve the use of toxic alkylphosphine, various surfactants and rigorous air-free conditions, which limit their large scale application.…”

Highly active nickel–cobalt/nanocarbon thin films as efficient water splitting electrodes

“…This procedure is modified from our previous report. 25 The resultant N-carbon film features unique advantages due to its porous structure and represents a favorable support with unique properties such as high electrical conductivity and enhanced electron transfer. Next, binary Ni x Co 1-x nanoparticles were deposited on the N-carbon film using designed bimetallic targets ( Fig.…”