A three dimensional (3D) graphene assembly with hierarchical pores (3DHPG) was prepared byhydrothermal assembly and subsequent carbon-thermal reaction induced etching. The structure andcomponent of the product were characterized by SEM, TEM, Raman, N2 adsorption-desorption, andXPS. The introduction of mesopores in basal plane of graphene in 3DHPG brings it more edge structure,more oxygen-containing defects, and larger surface area than typical 3D porous graphene foam (3DPG).Electrochemical study revealed the 3DHPG/GCE shows larger current response and improved masstransfer efficiency than 3DPG/GCE. Using dopamine as a model molecule, the 3DHPG/GCE showsmuch higher current response than that on 3DPG/GCE. The dopamine sensor based on 3DHPG/GCEdisplay a linear range of 0.01- 300 μM and a detection limit of 3 nM. The linear range is wider than thaton 3DPG (0.05-200 μM), and the detection limit is lower than that on 3DPG (20 nM). The improvedsensing performance can be attributed to the hierarchically porous structure with large surface area,efficient mass transfer and enhanced catalysis due to the introduction of mesopores. The 3Dhierarchically porous graphene assembly with unique structure and catalysis should be a promisingmaterial in electrochemical devices.
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