Bio‐Inspired Leaf‐Mimicking Nanosheet/Nanotube Heterostructure as a Highly Efficient Oxygen Evolution Catalyst

Abstract

Plant leaves represent a unique 2D/1D heterostructure for enhanced surface reaction and efficient mass transport. Inspired by plant leaves, a 2D/1D CoOx heterostructure is developed that is composed of ultrathin CoOx nanosheets further assembled into a nanotube structure. This bio‐inspired architecture allows a highly active Co2+ electronic structure for an efficient oxygen evolution reaction (OER) at the atomic scale, ultrahigh surface area (371 m2 g−1) for interfacial electrochemical reaction at the nanoscale, and enhanced transport of charge and electrolyte over CoOx nanotube building blocks at the microscale. Consequently, this CoOx nanosheet/nanotube heterostructure demonstrates a record‐high OER performance based on cobalt compounds reported so far, with an onset potential of ≈1.46 V versus reversible hydrogen electrode (RHE), a current density of 51.2 mA cm−2 at 1.65 V versus RHE, and a Tafel slope of 75 mV dec−1. Using the CoOx nanosheet/nanotube catalyst and a Pt‐mesh, a full water splitting cell with a 1.5‐V battery is also demonstrated.

Selectively Etching Vanadium Oxide to Modulate Surface Vacancies of Unary Metal–Based Electrocatalysts for High‐Performance Water Oxidation

“…[29] For Co x (V 1−x ), in the Nyquist plots (Figure 7a) which represents the lowest charge transfer resistance (R ct ) at the interface of electrocatalyst/electrolyte (Table S3, Supporting Information). [29] For Co x (V 1−x ), in the Nyquist plots (Figure 7a) which represents the lowest charge transfer resistance (R ct ) at the interface of electrocatalyst/electrolyte (Table S3, Supporting Information).…”

Carbon‐Based Metal‐Free Catalysts for Electrocatalysis beyond the ORR

“…However, their scarcity, high cost, and poor long-term stability have hindered the large-scale production of hydrogen. [34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49] In addition, ordered Ni 5 P 4 nanoarchitectures with a "sheetlike" morphology on a Ni foil were synthesized and found to be bifunctional catalysts for both the HER and the OER. [1] Many nonprecious-metal-based HER catalysts have been studied in the past decades with the aim of completely or partially replacing the noble metals.…”

A general ligand-assisted self-assembly approach to crystalline mesoporous metal oxides

“…Water electrolysis is considered a promising way to overcome the problem of fossil fuel depletion. Transition metal oxides such as Co 3 O 4 and NiO have been regarded as effective catalysts to replace the precious iridium and ruthenium oxides in the OER [24][25][26][27] . Here, we assessed the OER properties in a standard three-electrode system.…”