Noble metal-free two dimensional carbon-based electrocatalysts for water splitting

Abstract

Noble metal materials are widely employed as benchmark electrocatalysts to achieve electrochemical water splitting which comprises of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). However, the high cost and scarcity limit the wide ranging commercial applications of noble metal-based catalysts. Development of noble metal-free two dimensional (2D) carbon-based materials can not only reduce the consumption of noble metals, but also create materials with the characteristics of high active surface area, abundance, easy functionalization, and chemical stability, which may carve a way to promising electrochemical water splitting. In this review, noble metalfree 2D carbon-based electrocatalysts, including heteroatom (B, S, N, P, F, and O) doped graphene, 2D porous carbons modified with heteroatoms and/or transition metals, and 2D carbon-based hybrids are introduced as cost-effective alternatives to the noble metal-based electrocatalysts with comparable efficiencies to conduct HER, OER, and overall water splitting. This review emphasizes on current development in synthetic strategies and structure-property relationships of noble metal-free 2D carbon-based electrocatalysts, together with major challenges and perspectives of noble metal-free 2D carbon-based electrocatalysts for further electrochemical applications.

Recent Advances in Manifold Exfoliated Synthesis of Two‐Dimensional Non‐precious Metal‐Based Nanosheet Electrocatalysts for Water Splitting

“…[ 69 ] Moreover, the delaminated 2D nanosheet materials prepared by the top‐down method mostly possess the solution‐processable property, which largely enriches the applicability of these 2D nanosheets materials. Although the synthetic pathways and the electrochemical energy utilizations of various ultrathin 2D nanostructured materials have been summarized recently in a few literatures, [ 1,3,48,70–76 ] a comprehensive review on the progressive strategies of top‐down synthesis pathway, especially for exfoliation methods of guest ions or molecules‐, auxiliary force‐, electrochemical‐, plasma‐, pulsed laser‐, intermediate‐, thermal decomposition‐assisted, which are used to produce 2D NPMB nanosheets for the application in the evolution of O 2 and H 2 from electrocatalytic water splitting, is still remain missing. Herein, we have comprehensively reviewed and summarized the most recent advances in multifarious exfoliation methods of 2D NPMB materials and their electrochemical behaviors as highly efficient electrocatalysts in water splitting.…”

Hexagonal Boron Nitride as a Multifunctional Support for Engineering Efficient Electrocatalysts toward the Oxygen Reduction Reaction

“…As is well-known, carbon-based materials (e.g., activated carbon, carbon nanotubes, reduced graphene oxide) are extensively deployed as functional supports for noble metal NPs and other non-noble metal catalysts due to their high conductivity and appropriate chemical stability. − Unfortunately, a big challenge remains regarding the thermodynamic instability of carbon materials, and they tend to be oxidized at high operation potentials, which would consequently damage the structural integrity of the catalyst, cause agglomeration of noble metal NPs, and eventually result in degradation of catalytic activity. − Notably, the instability of the carbon support is considered to be one of the critical reasons for the inferior durability of the commercial Pt/C electrocatalyst for the oxygen reduction reaction (ORR) in fuel cells. , Graphene analogues, particularly reduced graphene oxide, have been extensively investigated as the active phases or functional supports for constructing hybrid electrocatalysts. , Graphene-like two-dimensional (2D) hexagonal boron nitride (h-BN), however, has not drawn intense attention in the electrocatalysis field, which is in great part due to its wide band gap (low conductivity) and electrochemical inertness. , Nevertheless, h-BN is a compound possessing exceptional chemical stability and antioxidation/corrosion capability in harsh environments. − We recently found that, compared to other typical carbonaceous materials, h-BN exhibits a superior antioxidation property at high potentials (Figure S1), strongly suggesting that h-BN has great potential to work as a robust support for confining the active noble metal NPs and constructing durable heterostructured catalysts. More importantly, h-BN contains large quantities of B and N, which would provide a unique chemical coordination environment and electronic interaction at the interfaces of the heterostructured catalysts .…”

“…23,24 Graphene analogues, particularly reduced graphene oxide, have been extensively investigated as the active phases or functional supports for constructing hybrid electrocatalysts. 25,26 Graphene-like two-dimensional (2D) hexagonal boron nitride (h-BN), however, has not drawn intense attention in the electrocatalysis field, which is in great part due to its wide band gap (low conductivity) and electrochemical inertness. 27,28 Nevertheless, h-BN is a compound possessing exceptional chemical stability and antioxidation/ corrosion capability in harsh environments.…”

A Bifunctional 2D Interlayered β‐Cu2V2O7/Zn2V2O6 (CZVO) Heterojunction for Solar‐Driven Nonsacrificial Dye Degradation and Water Oxidation

“…For OER, understanding the OER mechanism over the heterostructured photocatalyst requires detailed information on the reaction kinetics at the electrode/electrolyte interface and the interactions of the intermediates with the photocatalyst surface. [70,71] Given that the PEC measurements were carried out in a neutral medium, CZVO heterojunction could track the following steps for OER.…”