Customizable design strategies for high-performance bioanodes in bioelectrochemical systems

Abstract

Summary Bioelectrochemical systems (BESs) can fulfill the demand for renewable energy and wastewater treatment but still face significant challenges to improve their overall performance. Core efforts have been made to enhance the bioelectrode performance, yet, previous approaches are fragmented and have limited applicability, unable to flexibly adjust physicochemical and structural properties of electrodes for specific requirements in various applications. Here, we propose a facile electrode design strategy that integrates three-dimensional printing technology and functionalized modular electrode materials. A customized graphene-based electrode with hierarchical pores and functionalized components (i.e., ferric ions and magnetite nanoparticles) was fabricated. Owing to efficient mass and electron transfer, a high volumetric current density of 10,608 ± 1,036 A/m 3 was achieved, the highest volumetric current density with pure Geobacter sulfurreducens to date. This strategy can be readily applied to existing BESs (e.g., microbial fuel cells and microbial electrosynthesis) and provide a feasibility for practical application.

A Mini-Review on Applications of 3D Printing for Microbial Electrochemical Technologies

“…Similarly, surface modification of a 3D-printed polymeric electrode with copper could produce 12.3-fold higher power than copper mesh electrodes (Bian et al, 2018b). Most recently, He et al (2021) developed a 3D-printed graphene oxide (GO) aerogel anode with a customized printing ink combining GO, ferric ions, and magnetite nanoparticles. The hierarchical pores in their GO aerogel electrode could provide effective mass transfer of substrates, leading to 7.9 folds higher volumetric current output than carbon felt anode.…”

3D Composite PDMS/MWCNTs Aerogel as High-Performing Anodes in Microbial Fuel Cells

“…In the last decades, many works in the literature focused their attention on all the possible efforts to improve the MFCs’ performance in terms of power output, which results to be very low, leading thus to a discrepancy between the prospective technology and real-world applications [ 9 ]. Among all possible technological components, such as electroactive bacteria species, device architecture, ion exchange membrane, and organic substrates, bioelectrodes play a pivotal role in defining the MFCs’ performance [ 10 , 11 ]. Bioelectrodes, indeed, result to be the solid substrate on which the electroactive bacteria can proliferate, thus inducing biofilm formation and the consequent exchange of electrons [ 12 ].…”

“…Bioelectrodes, indeed, result to be the solid substrate on which the electroactive bacteria can proliferate, thus inducing biofilm formation and the consequent exchange of electrons [ 12 ]. To guarantee these features, the physiochemical properties and structures of electrodes are key factors that strictly affect the electron transfer at the biological/inorganic interface and define the maximum available surface area for the electroactive bacteria’s attachment and growth [ 10 , 11 , 12 ]. Carbon-based materials are considered one of the best-performing anode electrodes, able to combine the biocompatibility properties for the proliferation of microorganisms and the proper electrical conductivity, thus ensuring electron transfer from electroactive bacteria and anode electrodes [ 9 , 10 , 12 , 13 , 14 ].…”

Efficient Hydrogen Delivery for Microbial Electrosynthesis via 3D-Printed Cathodes

“…This includes the printing of metallic, porous 3D-structured materials ( Calignano et al, 2015 ; Zhou et al, 2017 ), conductive polymeric materials with subsequent surface modifications or carbonisation to increase conductivity and bio-compatibility ( You et al, 2017 ; Bian et al, 2018 ; Pumera, 2019 ), as well as the 3D printing of active bio-electrodes by direct incorporation of living bacteria ( Shewanella oneidensis MR-1) into a printable ink ( Freyman et al, 2020 ). Importantly, in a recent study He et al report the development of a 3D-printed graphene oxide aerogel anode, which achieved record volumetric current output using a pure culture of Geobacter sulfurreducens ( He et al, 2021 ). The authors attribute the performance increase to improved mass transfer properties of the material (compared to carbon felt) enabled by hierarchical pores in their 3D-printed anode ( He et al, 2021 ).…”

“…Importantly, in a recent study He et al report the development of a 3D-printed graphene oxide aerogel anode, which achieved record volumetric current output using a pure culture of Geobacter sulfurreducens ( He et al, 2021 ). The authors attribute the performance increase to improved mass transfer properties of the material (compared to carbon felt) enabled by hierarchical pores in their 3D-printed anode ( He et al, 2021 ). These results are a promising indication that 3D-printing presents a suitable tool to address the mass transfer limitation in hydrogen driven microbial CO 2 reduction.…”