Study of the Functionalities of a Biochar Electrode Combined with a Photoelectrochemical Cell

Spyridon Giannakopoulos; John Vakros; Ioannis D Manariotis; Dionissios Mantzavinos; Panagiotis Lianos

doi:10.3390/ma16010043

Study of the Functionalities of a Biochar Electrode Combined with a Photoelectrochemical Cell

Materials (Basel). 2022 Dec 21;16(1):43. doi: 10.3390/ma16010043.

Authors

Spyridon Giannakopoulos¹, John Vakros^{1

2}, Ioannis D Manariotis³, Dionissios Mantzavinos¹, Panagiotis Lianos¹

Affiliations

¹ Department of Chemical Engineering, University of Patras, 26504 Patras, Greece.
² School of Sciences and Engineering, University of Nicosia, Nicosia 2417, Cyprus.
³ Environmental Engineering Laboratory, Department of Civil Engineering, University of Patras, University Campus, 26504 Patras, Greece.

Abstract

Biochar has been obtained by pyrolysis of spent malt rootlets under limited oxygen supply and further activated by mixing with KOH and pyrolyzed again at high temperature. The total specific surface area of such activated biochar was 1148 m² g^-1, while that of micropores was 690 m² g^-1. This biochar was used to make a functional electrode by deposition on carbon cloth and was combined with a photoelectrochemical cell. The biochar electrode functioned as a supercapacitor in combination with the electrolyte of the cell, reaching a specific capacity of 98 Fg^-1, and it was capable of storing charges generated by the cell, proving current flow both under illumination and in the dark. The same electrode could be used as an air-cathode providing oxygen reduction functionality and thus demonstrating interesting electrocatalyst properties.

Keywords: biochar; electrocatalyst; oxygen reduction; photocatalytic fuel cell; photoelectrochemical cell; spent malt rootlets.

Grants and funding

This research was partially funded by the Hellenic Foundation for Research and Innovation (H.F.R.I.) under the “First Call for H.F.R.I. Research Projects to support Faculty members and Researchers and the procurement of high-cost research equipment grant” (Project Number: 81080).