3D Printed Mechanically Robust Graphene/CNT Electrodes for Highly Efficient Overall Water Splitting
Meiwen Peng,1 Danli Shi,1 Yinghui Sun,2 Jian Cheng,3 Bo Zhao,1 Yiming Xie,1 Junchang Zhang,1 Wei Guo,1 Zheng Jia,*,4 Zhiqiang Liang,*,3 and Lin Jiang*,1
1Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices. Soochow University, Suzhou, Jiangsu 215123, P. R. China.
2College of Energy Soochow Institute for Energy and Materials Innovations Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province. Soochow University. Suzhou, Jiangsu 215006, P. R. China.
3Department of Mechanical Engineering University of Maryland College Park, College Park, MD 20742, USA
4Department of Engineering Mechanics, Zhejiang University. Hangzhou 310027, P. R. China
3D printing of graphene electrodes with high mechanical strength has been a growing interest in the development of advanced energy, environment, and electronic systems, yet is extremely challenging. Herein, a 3D printed bioinspired electrode of graphene reinforced with 1D carbon nanotubes (CNTs) (3DP GC) with both high flexural strength and hierarchical porous structure is reported via a 3D printing strategy. Mechanics modeling reveals the critical role of the 1D CNTs in the enhanced flexural strength by increasing the friction and adhesion between the 2D graphene nanosheets. The 3DP GC electrodes hold distinct advantages: i) an intrinsically high flexural strength that enables their large-scale applications; and ii) a hierarchical porous structure that offers large surface area and interconnected channels, endowing fast mass and/or charge and ions transport rate, which is thus beneficial for acting as an ideal catalyst carrier. The 3DP GC electrode integrated with a NiFeP nanosheets array exhibits a voltage of 1.58 V at 30 mA cm−2 as bifunctional electrode for water splitting, which is much better than most of the reported Ni-, Co-, and Fe-based bifunctional electrocatalysts. Importantly, this study paves the way for the practical applications of 3D printed graphene electrodes in many energy conversion/storage, environmental, and electronic systems where high flexural strength is preferred.