Electrochemistry Studies of Hydrothermally Grown ZnO on 3D-Printed Graphene

Nanomaterials

Dimitra Vernardou¹  George Kenanakis² 

[1] Center of Materials Technology and Photonics, School of Engineering, Hellenic Mediterranean University, 710 04 Heraklion, Crete, Greece;Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas, N. Plastira 100, Vasilika Vouton, GR-700 13 Heraklion, Crete, Greece;

关键词: 3D-printed graphene;    zinc oxide;    hydrothermal growth;    electrochemical studies;   

DOI  :  10.3390/nano9071056

来源: DOAJ

【 摘 要 】

A three-dimensional (3D) printer was utilised for the three-dimensional production of graphene-based pyramids and an efficient hydrothermal procedure for ZnO growth. In particular, the 3D-printed graphene pyramids were forwarded in Pyrex glass bottles with autoclavable screw caps filled with 50 mL of an aqueous solution of zinc nitrate hexahydrate and hexamethylenetetramine for 1 h at 95 °C; sufficient enough time to deposit well-dispersed nanoparticles. X-ray diffraction patterns were in accordance with a Raman analysis and presented the characteristic peaks of graphite along with those of wurtzite ZnO. Different positions on the sample were tested, confirming the uniform dispersion of ZnO on graphene pyramids. From the electrochemical studies, it was found that the charging and discharging processes are affected by the presence of ZnO, indicating one well-defined plateau for each process compared to the previously reported bare graphene pyramids. In total, the material shows a value of 325 mAh g⁻¹, a capacitance retention factor of 92% after 5000 scans, and a coulombic efficiency of 100% for the first scan that drops to 85% for the 5000th scan. This excellent performance is the result of the effect of ZnO and graphene that combines two Li⁺ accommodation sites, and the contribution of graphene pyramids, which provides more available sites to favor lithium storage capacity. Hence, this anode may be a promising electrode material for lithium-ion batteries.

【 授权许可】

Unknown