Superstructures of Zeolitic Imidazolate Frameworks to Single‐ and Multiatom Sites for Electrochemical Energy Conversion

Abstract

The exploration of electrocatalysts with high catalytic activity and long‐term stability for electrochemical energy conversion is significant yet remains challenging. Zeolitic imidazolate framework (ZIF)‐derived superstructures are a source of atomic‐site‐containing electrocatalysts. These atomic sites anchor the guest encapsulation and self‐assembly of aspheric polyhedral particles produced using microreactor fabrication. This review provides an overview of ZIF‐derived superstructures by highlighting some of the key structural types, such as open carbon cages, 1D superstructures, hollow structures, and the interconversion of superstructures. The fundamentals and representative structures are outlined to demonstrate the role of superstructures in the construction of materials with atomic sites, such as single‐ and dual‐atom materials. Then, the roles of ZIF‐derived single‐atom sites for the electroreduction of CO2 and electrochemical synthesis of H2O2 are discussed, and their electrochemical performance for energy conversion is outlined. Finally, the perspective on advancing single‐ and dual‐atom electrode‐based electrochemical processes with enhanced redox activity and a low‐impedance charge‐transfer pathway for cathodes is provided. The challenges associated with ZIF‐derived superstructures for electrochemical energy conversion are discussed.

Ultrasensitive Dopamine Detection at Co3O4-Anchored N-Doped Hollow Mesoporous Carbon Nanospheres

“…The exhibited I D /I G ratios of the Co 3 O 4 /NDHCS samples are 1.14 (Co 3 O 4 /NDHCS-0.1), 1.20 (Co 3 O 4 /NDHCS-0.2), and 1.16 (Co 3 O 4 /NDHCS-0.3). It is worth to noting that the various loading amounts of the Co precursor effectively interact with the N precursor and significantly promote the higher defect site population under the carbonization process . Particularly, 0.2 g of the CoPc-loaded Co 3 O 4 /NDHCS-0.2 material implied higher defect sites along with minimum graphitization.…”

“…It is worth to noting that the various loading amounts of the Co precursor effectively interact with the N precursor and significantly promote the higher defect site population under the carbonization process. 43 Particularly, 0.2 g of the CoPc-loaded Co 3 O 4 /NDHCS-0.2 material implied higher defect sites along with minimum graphitization. It may be that most of the PDA and CoPc intermediates are efficiently bound and transformed into higher defect densities during the carbonization process.…”

Ultrafine Bimetallic Nickel–Cobalt Alloy from a Layered Hydroxide for Oxygen Evolution Reaction and Capacitors

“…Oxygen evolution reaction (OER) supplies protons and electrons for fuel-producing cathodic events such as hydrogen evolution reactions (HER) and CO 2 reduction reactions, however, it suffers from sluggish kinetics which requires decreased overpotential using tunable 3d metals such as Co-, Ni-, and Fe- as active sites with tunable electron configuration. , The high overpotential-driven OER represents overcoming the activation energy of hydrogen evolution reaction (HER), and OER is a significant barrier to the production of closed-cycle renewable fuel and chemicals . The operating condition (pH under alkaline or acidic medium), high potential of the anode, and transfer of four electrons and four protons restrict the selection of catalyst for OER to rare metals like iridium and ruthenium. ,, However, the large-scale application for noble metals faces restrictions due to their high price and limiting access. , The reactivity of oxygen atoms is linked to the stability and catalytic activity of metal oxides for the OER .…”

Electronic and Structural Engineering of Atomically Dispersed Isolated Single‐Atom and Alloy Architectures

“…As a consequence, the SACs can exhibit multiple adsorption states of surface species. [ 25 ] However, attaining a high atom‐utilization efficiency and maximum atomic dispersion remain unsolved. Metal–support interactions at high temperatures (e.g., 700–1100 °C) are crucial for maximizing the contribution of the atomic interface effect to achieve maximum atom‐utilization efficiency.…”