TY - JOUR
T1 - Photocatalytic-induced electron transfer via anode-respiring bacteria (ARB) at an anode that intimately couples ARB and a TiO2 photocatalyst
AU - Zhou, Dandan
AU - Dong, Shuangshi
AU - Ki, Dongwon
AU - Rittmann, Bruce
N1 - Funding Information:
We acknowledge and appreciate GRSP funding from Graduate and Professional Student Association (GPSA) at Arizona State University and from the National Natural Science Foundation of China – China ( 51722803 , 51678270 ). We thank and acknowledge Dr. César I. Torres and Dr. Sudeep C. Popat for their valuable discussion and suggestions on this work.
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/4/15
Y1 - 2018/4/15
N2 - A novel anode that intimately couples anode-respiring bacteria (ARB) with a nitrogen-doped TiO2 photocatalyst on a porous carbon foam electrode (the ICPB-anode) was fabricated and experimentally tested in an electrochemical cell. ARB are well known for obtaining energy by transferring bio-metabolized electrons to the anode, an external solid acceptor. The goal of this work was to identify if and how ARB play a role in transporting photo-generated electrons. When simulated visible-light illuminated an ICPB-anode, the current increased by ∼3 A/m2 (∼30% of the total), due to photocatalytically generated electrons (photo-electrons). In contrast, an abiotic photocatalyst anode (photo-anode) was incapable of transfering photo-electrons. Compared to a non-photocatalytic biofilm-anode, the Coulombic efficiency increased by 15–20% with the ICPB-anode, and the effect was due to the addition of electron flow from photocatalytic water electrolysis, since oxidation of the organic electron donor was unchanged. Electrochemical impedance analyses showed that the Ohmic resistance of the ICPB-anode decreased by ∼98%, compared with the abiotic photo-anode. A redox-potential window typical of ARB's c-type cytochromes was up-regulated when the ARB transported photo-electrons, supporting that c-type cytochromes were the significant redox proteins for transferring photo-electrons. All the results combine to show that ARB were responsible for the transport of electrons generated by photocatalysis in the ICPB-anode.
AB - A novel anode that intimately couples anode-respiring bacteria (ARB) with a nitrogen-doped TiO2 photocatalyst on a porous carbon foam electrode (the ICPB-anode) was fabricated and experimentally tested in an electrochemical cell. ARB are well known for obtaining energy by transferring bio-metabolized electrons to the anode, an external solid acceptor. The goal of this work was to identify if and how ARB play a role in transporting photo-generated electrons. When simulated visible-light illuminated an ICPB-anode, the current increased by ∼3 A/m2 (∼30% of the total), due to photocatalytically generated electrons (photo-electrons). In contrast, an abiotic photocatalyst anode (photo-anode) was incapable of transfering photo-electrons. Compared to a non-photocatalytic biofilm-anode, the Coulombic efficiency increased by 15–20% with the ICPB-anode, and the effect was due to the addition of electron flow from photocatalytic water electrolysis, since oxidation of the organic electron donor was unchanged. Electrochemical impedance analyses showed that the Ohmic resistance of the ICPB-anode decreased by ∼98%, compared with the abiotic photo-anode. A redox-potential window typical of ARB's c-type cytochromes was up-regulated when the ARB transported photo-electrons, supporting that c-type cytochromes were the significant redox proteins for transferring photo-electrons. All the results combine to show that ARB were responsible for the transport of electrons generated by photocatalysis in the ICPB-anode.
KW - Anode respiring bacteria
KW - C-type cytochrome
KW - Couple
KW - Electron transfer
KW - Photocatalysis
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U2 - 10.1016/j.cej.2018.01.094
DO - 10.1016/j.cej.2018.01.094
M3 - Article
AN - SCOPUS:85044462418
VL - 338
SP - 745
EP - 751
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
SN - 1385-8947
ER -