Issue 35, 2018

Porous nickel hollow fiber cathodes coated with CNTs for efficient microbial electrosynthesis of acetate from CO2 using Sporomusa ovata

Abstract

Microbial electrosynthesis (MES) allows recycling of CO2 into value added products by coupling renewable energy to the microbial ability for complex product formation. To improve biofilm formation on the cathode and the rates of product generation, the design of cathodes possessing a high specific surface area and enhanced electrode–microbe electron transfer is needed. This study aimed to demonstrate a novel cathode design that is made of porous nickel hollow fibers (Ni-PHFs), for facilitating direct delivery of CO2 to Sporomusa ovata in MES through the pores in the hollow fibers. Modification of the surface of Ni-PHFs with carbon nanotubes (CNTs) resulted in an 11-fold increase in the CO2 adsorption capability at atmospheric pressure, as well as 76.3% reduction of cathode electron transfer resistance. This cathode surface modification partially explained the higher acetate production rate of 247 ± 17 mM d−1 m−2 from direct CO2 delivery through the pores of the Ni-PHF/CNT cathode, compared to 145 ± 4 mM d−1 m2 for the Ni-PHF cathode. Higher electron recovery in the form of acetate (∼83%) was also observed for the Ni-PHF/CNT cathode. As for the tests where CO2 was sparged into the medium, acetate production was 36% lower than tests with direct CO2 delivery to S. ovata through the pores of the Ni-PHF/CNT cathode. These results demonstrate that using the PHF electrode design and modifying the cathode morphology to enhance the microbe–electrode interactions and CO2 availability for bacterial growth are effective approaches to increase the rates of CO2 reduction in MES.

Graphical abstract: Porous nickel hollow fiber cathodes coated with CNTs for efficient microbial electrosynthesis of acetate from CO2 using Sporomusa ovata

Supplementary files

Article information

Article type
Paper
Submitted
05 Jun 2018
Accepted
14 Aug 2018
First published
15 Aug 2018

J. Mater. Chem. A, 2018,6, 17201-17211

Porous nickel hollow fiber cathodes coated with CNTs for efficient microbial electrosynthesis of acetate from CO2 using Sporomusa ovata

B. Bian, M. F. Alqahtani, K. P. Katuri, D. Liu, S. Bajracharya, Z. Lai, K. Rabaey and P. E. Saikaly, J. Mater. Chem. A, 2018, 6, 17201 DOI: 10.1039/C8TA05322G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements