초록
<P><B>Abstract</B></P> <P>Hydrogen (H<SUB>2</SUB>) gas represents renewable resource candidate to traditional energy resource. Methods to promote the H<SUB>2</SUB> evolution rate attract increasing attentions. In the present research, ferric oxide/carbon nanoparticles (FOCNPs) were synthesized and evaluated the feasibility to enhance the production rate of H<SUB>2</SUB> gas from glucose through anaerobic fermentation by mixed bacteria. The results demonstrated that appropriate dose of FOCNPs promoted, while excessive concentration of FOCNPs suppressed the production of H<SUB>2</SUB>. Addition of 200 mg/L FOCNPs resulted in the highest yield of 218.63 ml H<SUB>2</SUB>/g glucose, 33.7% higher than 163 ml H<SUB>2</SUB>/g glucose of the control test without addition of FOCNPs. However, 400 mg/L of FOCNPs inhibited the H<SUB>2</SUB> evolution to 154 ml/g glucose, 5.5% lower than the control. It was revealed that the H<SUB>2</SUB> evolution followed the acetic pathways. The FOCNPs had a specific surface area of 27.63 m<SUP>2</SUP>/g, and thus addition of FOCNPs could provide more attachment sites for the growth of anaerobes. Moreover, FOCNPs could promote the activity of hydrogenase and electron transfer efficiency, beneficial for the bio-H<SUB>2</SUB> evolution. However, excessive addition of FOCNPs could be toxic to microbes, and further suppressing the H<SUB>2</SUB> production. The present research provided an effective method to promote the evolution rate of H<SUB>2</SUB> gas.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Fe<SUB>2</SUB>O<SUB>3</SUB>/C nanoparticles (FOCNPs) was used in hydrogen (H<SUB>2</SUB>) fermentation. </LI> <LI> Suitable FOCNPs could enhance hydrogenase activity and electron transfer. </LI> <LI> FOCNPs could facilitate hydrogen-producing bacteria growth and richness. </LI> <LI> Both Gompertz and logistic models fitted well the H<SUB>2</SUB> fermentation process. </LI> <LI> Addition of 200 mg/L FOCNPs improved H<SUB>2</SUB> production by 33.7%. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Ferric oxide/carbon nanoparticles (FOCNPs) was synthesized and subsequently utilized in hydrogen (H<SUB>2</SUB>) fermentation via glucose-fed anaerobic mixed bacteria at 37 °C. FOCNPs served as not only a support carrier of anaerobes to improve cell growth, but also a biocatalyst to promote hydrogenase activity and electron transfer efficiency in the H<SUB>2</SUB> production.</P> <P>[DISPLAY OMISSION]</P>