Graphene as Thinnest Coating on Copper Electrodes in Microbial Methanol Fuel Cells

Abstract

Dehydrogenation of methanol (CH3OH) into direct current (DC) in fuel cells can be a potential energy conversion technology. However, their development is currently hampered by the high cost of electrocatalysts based on platinum and palladium, slow kinetics, the formation of carbon monoxide intermediates, and the requirement for high temperatures. Here, we report the use of graphene layers (GL) for generating DC electricity from microbially driven methanol dehydrogenation on underlying copper (Cu) surfaces. Genetically tractable Rhodobacter sphaeroides 2.4.1 (Rsp), a nonarchetypical methylotroph, was used for dehydrogenating methanol at the GL-Cu surfaces. We use electrochemical methods, microscopy, and spectroscopy methods to assess the effects of GL on methanol dehydrogenation by Rsp cells. The GL-Cu offers a 5-fold higher power density and 4-fold higher current density compared to bare Cu. The GL lowers charge transfer resistance to methanol dehydrogenation by 4 orders of magnitude by mitigating issues related to pitting corrosion of underlying Cu surfaces. The presented approach for catalyst-free methanol dehydrogenation on copper electrodes can improve the overall sustainability of fuel cell technologies.

Graphene-Infused Hybrid Biobattery–Supercapacitor Powered by Wastewater for Sustainable Energy Innovation

“…Our own studies have demonstrated that the CVD-based graphene materials on metal substrates neither restrict cell attachment nor biofilm growth of micro-organisms such as sulfate-reducing bacteria [15,16]. Additionally, our recent studies have shown that graphene materials based on CVD [28] and plasma exfoliation (the method used in this study) provide conducive environments for promoting cell attachment and growth of biofilms based on methylotrophs in microbial fuel cell applications. Similarly, a study by Wang et al also suggests that 3D graphene-nickel foam electrodes offer a high volumetric power density of 661 W/m 3 in microbial fuel cells, which typically rely upon biofilm growth [29].…”

Quantum enhanced efficiency and spectral performance of paper-based flexible photodetectors functionalized with two dimensional materials

“…In recent years, a wide variety of narrow band gap semiconductor-based PDs have been reported [29][30][31][32][33][34][35][36][37][38][39][40]. Such PDs are still restricted in practical application of devices because of lacking broadband absorption, low stability and slow responses.…”