Defect‐Derived Catalysis Mechanism of Electrochemical Reactions in Two‐Dimensional Carbon Materials

Abstract

In the past decades, remarkable progress has been achieved in the exploration of electrocatalysts with high activity, long durability, and low cost. Among these, defective graphene (DG)‐based catalysts are considered as one of the most potential substitutes for precious metal‐based electrocatalysts. DG‐based catalysts contain abundant active centers with different configurations resulting from their extraordinary high‐structural tunability. Herein, an overview on recent advancements in developing four kinds of DG‐based catalysts is presented: 1) heteroatoms‐doped graphene; 2) intrinsic DG (vacancy and topological defect); 3) nonmetal atoms or/and metal species‐modified intrinsic DG (heterogeneous species and intrinsic defects co‐tuned DG); and 4) DG‐based van der Waals‐type multilayered heterostructures. In particular, the synergistic effects between various defects are discussed, and the origin of catalytic activity is reviewed. Meanwhile, the established defect‐derived catalytic mechanism is summarized, which is beneficial for the rational design and fabrication of high‐performance electrocatalysts for practical energy‐related applications. Finally, challenges and future research directions on defect engineering in noble metal‐free materials for electrocatalysis are proposed.

Advancements in defect engineering of two-dimensional nanomaterial-based membranes for enhanced gas separation

“…2(a)). 32,33 These defects, arising during the synthesis of 2D materials, predominantly comprise nanoscale inherent defects and microscale large tears. 34 Nanoscale inherent defects, based on their pore sizes, are capable of effectuating efficient gas molecule separation.…”

DFT-assisted low-dimensional carbon-based electrocatalysts design and mechanism study: a review

“…Adsorption-free energies (ΔG) of key intermediates are utilized as activity descriptors for recognized reactions, including ΔG H for HER ( Han et al, 2023b ), ΔG O for ORR ( Han et al, 2023a ), ΔG CO for CO 2 RR ( Chen et al, 2022a ), and ΔG N for NRR ( Fang et al, 2023 ). For instance, DFT calculations were conducted on the MoS 2 edge, yielding a ΔG H of 0.08 eV, which closely approaches the optimal value of 0 eV ( Hinnemann et al, 2005 ).…”

“…However, the scarcity and high cost impede their industrial mass production. Therefore, non-noble metals and even metal-free electrocatalysts have been intensively studied and remarkable progress has been reached ( Yan X et al, 2016 ; Sui et al, 2017 ; Zhang L et al, 2018 ; Liu et al, 2019 ; Han et al, 2023a ; He et al, 2023 ). Up to now, low-dimensional carbon materials, such as 2D graphene nanosheets (G), 1D carbon nanotubes (CNT), and 0D fullerenes, have been widely used for fabricating a series of non-noble metals and even metal-free catalysts for energy conversion.…”

Regulation of heterogeneous electron transfer reactivity by defect engineering through electrochemically induced brominating addition

“…In contemporary research, it is widely acknowledged that the introduction of defects into the crystalline lattice of graphene represents an effective strategy for enhancing the HET activity of this remarkable carbon allotrope. 7,8 Although the precise underlying mechanisms remain the subject of ongoing investigation, it is generally believed that defect engineering, denoting the precise and quantitative regulation of defects, can disrupt the highly delocalized π-conjugated system of graphene. This disruption, in turn, results in an increase in the localized electronic density of states (DOS) near the Fermi level, thereby enhancing the reactivity of graphene in catalytic processes.…”