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 CoO _x heterostructure is developed that is composed of ultrathin CoO _x 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 CoO _x nanotube building blocks at the microscale. Consequently, this CoO _x 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 CoO _x nanosheet/nanotube catalyst and a Pt-mesh, a full water splitting cell with a 1.5-V battery is also demonstrated.

SUBMITTER: Wang Y 

PROVIDER: S-EPMC5024083 | biostudies-literature | 2015 Apr

REPOSITORIES: biostudies-literature