Effect of Escherichia coli on the photocatalytic behavior of TiO2 nanoparticles for H2 evolution from water

Abstract

Various microorganisms are present in natural waters, and understanding their impact on the photocatalytic behavior of photocatalysts is crucial, especially in large-scale hydrogen production. In line with this, we conducted a systematic investigation into the influence of Escherichia coli on the photocatalytic performance of TiO2 nanoparticles for H2 evolution. The findings revealed a significant reduction in the photocatalytic activity of TiO2 nanoparticles in the presence of Escherichia coli. Specifically, the H2 evolution rate was observed to be 57% lower (8.3 mmol g−1 h−1) compared to when Escherichia coli was absent (19.1 mmol g−1 h−1). The primary reason for this phenomenon appears to be the rupture of Escherichia coli cells during the photocatalytic process. As a result, intracellular proteins are released and subsequently adsorbed onto the surface of TiO2 nanoparticles, impeding the photocatalytic hydrogen evolution reaction. These results provide valuable insights that can inform the design of future photocatalytic hydrogen production processes.