Ag₂S Quantum Dots for Use in Whole-Cell Biohybrid Catalyst for Visible-Light-Driven Photocatalytic Organic Pollutant Degradation

Semiartificial photosynthetic systems have shown tremendous potential to address global energy issues by combining the exceptional optical properties of nanomaterials with biological whole-cell catalysts. To achieve sustainable energy conversion between inorganic materials and whole cells in semiartificial photosynthetic systems, it is highly desirable to introduce biocompatible nanomaterials with broad light adsorption into the hybrid catalysis system. Herein, we developed a whole-cell biohybrid catalyst with in situ synthesized Ag2S QDs for visible-light-driven photocatalytic organic pollutant degradation. With the synthesized Ag2S QDs on the surface of engineered Escherichia coli cells, the biohybrid system showed superior performance for the photocatalytic degradation of organic pollutants. The photogenerated reactive oxygen species (•O2–) were confirmed to play a pivotal role in removing organic pollutants during the photocatalytic process. The enhanced photocatalytic activity of the E. coli-Ag2S QD biohybrid system could be ascribed to the effective separation and transfer of the interfacial charge carriers. This whole-cell biohybrid system could provide a promising approach for environmental issues in solar energy conversion.