Enhanced bio-hydrogen production by photo-fermentation of corn stalk using Fe-doped CaTiO3 photocatalyst

• Published in: Energy (Oxford) 2024-08, Vol.301, p.131682, Article 131682
• Main Authors: Yang, Xudong, Zhang, Huan, Zhang, Zhiping, Li, Yameng, Liu, Hong, Zhang, Feng, Xiang, Guanning, Zhang, Quanguo
• Format: Article
• Language: English
• Subjects: Biohydrogen production; Corn stover; Fe-doped CaTiO3; Photo fermentation; Photocatalysts; Photosynthetic bacterium
• ISSN: 0360-5442
• DOI: 10.1016/j.energy.2024.131682

The aim of this study was to analyze the effects of CaTiO3 photocatalysts doped with different concentrations of Fe on the biohydrogen production process by photo-fermentation using corn stover as the substrate. The experimental results showed that the maximum cumulative hydrogen production and the maximum rate of hydrogen production were obtained when the doping concentration was 6 % (g/g) (380.8 mL, 26.4 mL/h), which were 63.4 % and 203.4 % higher, respectively, than those of the blank control group (233 mL, 8.7 mL/h). The substrate conversion rate was 32.82 %. Iron-doped CaTiO3 lowered the oxygen reduction potential in the fermentation system to provide a suitable reduction environment for the growth and fermentation of photosynthetic bacteria. The lowest redox potential observed was −393.5 mV for 6 % iron-doped CaTiO3. Thermogram analysis revealed a strong correlation between cumulative hydrogen production and redox potential. Additionally, the analysis of soluble small molecules showed that iron-doped CaTiO3 could inhibit the production of ethanol from glycolysis during fermentation and promote the utilization of small molecule acids. [Display omitted] •Fe-doped CaTiO3 improves the efficiency of photo fermentative hydrogen production.•The maximum hydrogen production rate increased by 203.4 %.•The maximum cumulative hydrogen production increased by 63.4 %.•Adding Fe-doped CaTiO3 can inhibit glycolysis to produce ethanol.•Adding Fe-doped CaTiO3 can improve the reducibility of fermentation broth.