Flame‐Assisted Synthesis of O‐Coordinated Single‐Atom Catalysts for Efficient Electrocatalytic Oxygen Reduction and Hydrogen Evolution Reaction

Abstract

Single‐atom catalysts (SACs) exhibit intriguing performance in electrocatalysis owing to their maximized atom utilizations and unique electronic structures, but effective anchoring metal atoms with defined coordination structure on hierarchical integrated electrode remain a challenge. Herein, a fast and facial flame‐assisted strategy is developed to construct oxygen‐coordinated SACs on integrated carbon nanotube (CNT) arrays with promising applications in electrocatalysis. Density functional theory calculations show that oxygen in carbon substrate imparts homogeneous sites for the efficient anchoring of metal atoms, thereby enabling SACs to disperse uniformly and firmly and thus bringing optimized activities. Moreover, the integrated CNT array with abundant oxygen‐containing groups is constructed and has been used as an efficient matrix for anchoring metal atoms (CNT‐O@M) via a flame‐assisted method. The as‐prepared CNT‐O@M (M = Co and Pt as typical examples) shows excellent activities in electrocatalytic oxygen reduction reaction and hydrogen evolution reaction with utilization of active site as high as 75.7%, which is superior to the reported SACs. Particularly, the performance of CNT‐O@M can maintain stably under various harsh conditions, showing a promising prospect in the long‐time applications. The methodology and concept proposed in this work could be extended to the synthesis of a variety of integrated SACs for efficient electrocatalysis.

Establishing a multifunctional solid electrolyte interphase on a 3D host by an ultra-fast double coating strategy for stable lithium metal batteries

“…Specically, the ethanol ame treatments only take a few seconds, and the loading mass can be readily controlled by regulating the number of repetitions, which is time-efficient and suitable for large-scale production. Although such ame treatments were previously utilized to grow carbon nanotubes on various substrates, 23,24 to the best of our knowledge, the growth of atmosphere-sensitive sulfur compounds has been scarcely achieved. In this work, by utilizing thioacetamide, the successful conversion of oxides to sulde/sulfates with high yield is demonstrated (the atomic S ratio of 6.43% in MSEI@Cu).…”

Tuning the Coordination Environment of Carbon‐Based Single‐Atom Catalysts via Doping with Multiple Heteroatoms and Their Applications in Electrocatalysis

“…SACs with the above structures have shown excellent electrocatalytic performance. [ 51–55 ] Compared with doping heteroatoms, recent reports have demonstrated that the coordination environment of carbon‐based SACs can be exactly controlled by exploiting the differences of various heteroatoms. [ 56–58 ]…”

“…SACs with the above structures have shown excellent electrocatalytic performance. [51][52][53][54][55] Compared with doping heteroatoms, recent reports have demonstrated that the coordination environment of carbon-based SACs can be exactly controlled by exploiting the differences of various heteroatoms. [56][57][58] Although some outstanding reviews have been provided on regulating the coordination environment of carbon-based SACs, [59][60][61][62] most of them have focused on the structures of active sites without describing the detailed methods and strategies involved.…”

Nanotubular TiOxNy-Supported Ir Single Atoms and Clusters as Thin-Film Electrocatalysts for Oxygen Evolution in Acid Media

“…The SMSI effect is significantly enhanced in the case of single-atom catalysts (SACs), which provide exceptional atom utilization efficiency. , It is well known that catalytic performance is controlled by the accessible surface area and intrinsic activity per active site, which has been shown to be maximized with the utilization of SACs. − However, the synthesis of SACs for OER that do not contain carbon is still in its infancy, with not many developed preparation strategies for the Ir SACs, in particular in acidic media. Examples of synthetic strategies include an in situ cryogenic–photochemical reduction method (for Ir single-atom sites on NiFe oxyhydroxides), electrochemical methods (for Ir SAC on a nickel-iron sulfide nanosheet array substrate), co-electrodeposition methods (Ir SAC on ultrathin NiCo 2 O 4 nanosheets), chemical reduction method (Ir SAC on CoO x amorphous nanosheets with abundant surface absorbed oxygen; Ir SAC incorporated in Co-based hydroxide nanosheets), and thermal decomposition method (Ir SAC on the NiO matrix) .…”