Sub‐2 nm Thiophosphate Nanosheets with Heteroatom Doping for Enhanced Oxygen Electrocatalysis

Abstract

Developing an efficient bifunctional electrocatalyst with accelerated kinetics is important but challenging for rechargeable metal‐air batteries. In this study, a series of anion‐regulated sub‐2 nm ultrathin thiophosphate nanosheets (NiPS3–xSex NSs) is rationally designed and synthesized as bifunctional oxygen evolution/reduction reaction (OER/ORR) electrocatalysts for Zn‐air batteries. The increase of nominal Se dopants (0 ≤ x ≤ 0.5) leads to the expansion of (001) crystal plane spacing and partially disordered structure generation after the incorporation of Se to pristine NiPS3. More importantly, electronic structures of active sites can be reasonably regulated via coordination of the interaction between anions and cations. Density functional theory calculations reveal that such tailored electronic structures reduce the overpotential of the thermodynamic barriers step for both OER and ORR as well as shorten energy bandgap, which can accelerate reaction kinetics in electrocatalytic processes and enhance electrical conductivity. Consequently, the obtained NiPS3–xSex NSs exhibit low OER overpotential (250 mV) and positive ORR onset potential (0.94 V), large power density (152 mW cm−2), and robust stability (96 h cycle) for Zn‐air devices, far exceeding that of precious metal catalysts. This study provides a novel tactic to design earth‐abundant and highly efficient bifunctional electrocatalysts for metal‐air battery technologies.

Electronic Modulation Caused by Interfacial Ni‐O‐M (M=Ru, Ir, Pd) Bonding for Accelerating Hydrogen Evolution Kinetics

“…This indicates the enhanced conductivity of Ru@Ni-MOF demonstrated by the small charge transfer resistance from EIS (Supporting Information, Figure S15). [41] The d-band center theory states that the electron density near the Fermi level can affect the binding Angewandte Chemie Communications energy of the reaction intermediate. [42] The 3d orbitals of Ni and Ru atoms of Ru@Ni-MOF show much higher PDOS near Fermi level than that of Ni-MOF and Ru NPs (Supporting Information, Figure S26), respectively, indicating the stronger interaction between the active sites and intermediates.…”

Electronic Modulation Caused by Interfacial Ni‐O‐M (M=Ru, Ir, Pd) Bonding for Accelerating Hydrogen Evolution Kinetics

“…This indicates the enhanced conductivity of Ru@Ni-MOF demonstrated by the small charge transfer resistance from EIS (Supporting Information, Figure S15). [41] The d-band center theory states that the electron density near the Fermi level can affect the binding Angewandte Chemie Zuschriften energy of the reaction intermediate. [42] The 3d orbitals of Ni and Ru atoms of Ru@Ni-MOF show much higher PDOS near Fermi level than that of Ni-MOF and Ru NPs (Supporting Information, Figure S26), respectively, indicating the stronger interaction between the active sites and intermediates.…”

MXenes as a versatile platform for reactive surface modification and superior sodium‐ion storages

“…The continuous growth of the global population and economy dramatically raises the demands for energy supply, which brings about skyrocketing environmental issues. [1,2] Upon the urgent application of clean energy harvesting technologies including solar, wind, tidal, etc., [3][4][5] developing large-scale electrochemical energy storage devices (EESDs) becomes critical for efficiently utilizing these intermittent renewable energies. [6][7][8] Among various EESDs, great success has been achieved in lithium-ion batteries (LIBs) since the 1990s, and have been rapidly developed into a major force in energy storage.…”