Controlled synthesis of mesoporous nanostructured anatase TiO₂ on a genetically modified Escherichia coli surface for high reversible capacity and long-life lithium-ion batteries

TiO₂ is a promising anode material for lithium-ion batteries. The electrochemical performance of TiO₂ can be improved by optimization of nanostructures. The present study was proposed to control the synthesis of mesoporous nanostructured anatase TiO₂ on a genetically modified Escherichia coli surface. A recombinant protein INP-SiliSila containing functional domains of silicatein-α and silaffin was constructed and expressed on the E. coli surface. Deposition of the TiO₂ precursor was facilitated by INP-SiliSila on the E. coli surface. Upon calcination, TiO₂ coating on the E. coli surface transformed to anatase and formed well-defined rod-shaped particles. The electrochemical performance of the as-prepared anatase TiO₂ as anode electrodes was improved and better than that of most reported ones. The present study not only provides an organism-based approach for fabricating nanostructured anatase TiO₂ with enhanced electrochemical performance, but also opens a new avenue to take advantage of genetically modified bacterial surfaces in the synthesis and structure control of materials.