Improvement in the Photobiological Hydrogen Production of Aggregated <i>Chlorella</i> by Dimethyl Sulfoxide

Abstract

Abstract Photobiological hydrogen production plays a vital role in generating clean renewable energy owing to its low energy consumption and environmental friendliness. Although materials‐induced Chlorella aggregates have been developed to achieve sustained photobiological hydrogen production under normal aerobic conditions, the yield is relatively low and equals only 0.42 % of the light‐to‐H 2 energy‐conversion efficiency. Herein, we report that only 0.5 vol % dimethyl sulfoxide in an aqueous environment significantly enhances the H 2 yield produced by aggregated Chlorella , reaching 0.69 % of the light‐to‐H 2 energy‐conversion efficiency. This improvement can be attributed to an increase in the cellular respiration rate by dimethyl sulfoxide, which results in a decrease in the oxygen content inside the aggregates and, ultimately, to the activation of more hydrogenases. More generally, this strategy consists of a functional enhancement in organism–material hybrids by using small molecules.