New insights into the role of CO2 in a photocatalytic fuel cell

• Published in: Journal of power sources Vol. 487; p. 229438
• Main Authors: Yu, Youxu, Xie, Fengjia, Chen, Rong, Zhu, Xun, Liao, Qiang, Ye, Dingding, Li, Jinwang, Song, Sihong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2021
• Subjects: CO2 saturated electrolyte; Methanol generation; Photoanode; Photocatalytic fuel cell; Photocatalytic reduction of CO2; Photocatalytic fuel cell; Methanol generation; Photoanode; CO2 saturated electrolyte; Photocatalytic reduction of CO2
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2020.229438

The objective of this work is to explore the role of CO2 in the photocatalytic fuel cell with TiO2 as the photoanode and methanol as a fuel under acid condition by making the anode electrolyte saturated with CO2. It is interesting to find that the performance of the photocatalytic fuel cell can be improved at low methanol concentration in the presence of CO2. This is probably because TiO2 has an adequate conduction band for photocatalytic reduction of CO2 to organics at the photoanode, which increases the methanol concentration at the catalytic surface to alleviate the mass transfer issue encountered in the low methanol concentration operation, and hinders the recombination of the electron-hole pairs. Moreover, the methanol concentration at the outlet of the photoanode can be even higher than the supplied methanol concentration. However, this effect is weakened and even disappears as the supplied methanol concentration increases. This work gives new insights into the role of CO2 in the photocatalytic fuel cell with the photoanode having an adequate conduction band for photocatalytic reduction of CO2. [Display omitted] •Photocatalytic fuel cell with TiO2 as the photoanode is developed.•Photocatalytic fuel cell is fueled with CO2 saturated methanol-H2SO4 solution.•Photocatalytic fuel cell performance can be boosted in the presence of CO2.•Methanol concentration at the outlet is even higher than that at the inlet.