High-power biofuel cells based on three-dimensional reduced graphene oxide/carbon nanotube micro-arrays

Yin Song; Chunlei Wang

doi:10.1038/s41378-019-0081-2

High-power biofuel cells based on three-dimensional reduced graphene oxide/carbon nanotube micro-arrays

Microsyst Nanoeng. 2019 Sep 23:5:46. doi: 10.1038/s41378-019-0081-2. eCollection 2019.

Authors

Yin Song¹, Chunlei Wang¹

Affiliation

¹ Department of Mechanical and Materials Science Engineering, Florida International University, 10555 West Flagler Street, Miami, FL 33174 USA.

Abstract

Miniaturized enzymatic biofuel cells (EBFCs) with high cell performance are promising candidates for powering next-generation implantable medical devices. Here, we report a closed-loop theoretical and experimental study on a micro EBFC system based on three-dimensional (3D) carbon micropillar arrays coated with reduced graphene oxide (rGO), carbon nanotubes (CNTs), and a biocatalyst composite. The fabrication process of this system combines the top-down carbon microelectromechanical systems (C-MEMS) technique to fabricate the 3D micropillar array platform and bottom-up electrophoretic deposition (EPD) to deposit the reduced rGO/CNTs/enzyme onto the electrode surface. The Michaelis-Menten constant K_M of 2.1 mM for glucose oxidase (GOx) on the rGO/CNTs/GOx bioanode was obtained, which is close to the K_M for free GOx. Theoretical modelling of the rGO/CNT-based EBFC system via finite element analysis was conducted to predict the cell performance and efficiency. The experimental results from the developed rGO/CNT-based EBFC showed a maximum power density of 196.04 µW cm^-2 at 0.61 V, which is approximately twice the maximum power density obtained from the rGO-based EBFC. The experimental power density is noted to be 71.1% of the theoretical value.

Keywords: Electronic properties and materials; Nanoscale materials.