Boosting solar hydrogen production via electrostatic interaction mediated E. coli-TiO_2−x biohybrid system

Hydrogen is garnering growing attention as a green energy source with zero carbon emissions. However, most hydrogen production technologies still rely on the consumption of fossil fuels and are therefore unsustainable. This has driven the search for more environmentally friendly methods of hydrogen production. In this work, we present an innovative approach to enhance hydrogen generation via electrostatic interaction in the Escherichia coli and defective titanium dioxide (TiO_2−x) biohybrids. Our method involves narrowing the forbidden bandwidth of TiO₂ while introducing defect bands into its conduction band to facilitate visible light absorption and efficient charge separation. This biohybrid system, consisting of E. coli and TiO_2−x, demonstrates a remarkable capability to produce 1.25 mmol of hydrogen within a 3-h timeframe under visible light irradiation. This accomplishment signifies a 3.31-fold rise in hydrogen production in comparison to E. coli, signifying a substantial enhancement in hydrogen production efficiency. Furthermore, we delve into the alterations in biological metabolites associated with hydrogen production and the changes in electron transfer in different biohybrid systems. It provides valuable insights into the understanding of the intrinsic mechanisms that drive the process. This work introduces a novel and promising avenue for achieving this exciting goal.