In situ preparation of PDA decorated Ag/black mesoporous TiO2 nanocomposites for photocatalytic and antibacterial applications

Driven by clean solar energy, photocatalytic technology can effectively degrade organic pollutants and kills pathogenic bacteria. Researchers are always devoted to developing more economical and efficient photo-catalysts. In this work, mesoporous TiO2 nanoparticles (MTN) with controlled diameters (100-200 nm) and large specific surface areas (similar to 112 m(2)/g) were prepared via a simple sol-gel method. Then, 10 wt% Ag nanocrystals (similar to 5 nm) were in situ generated in the MTN via solvothermal process, Ti3+ and oxygen vacancies also been introduced on their surface, thereby leading to a narrowed bandgap (similar to 2.9 eV) and strong absorption in the visible region. Finally, polydopamine (PDA) was decorated on the surface of Ag/bMTN to further improve their dispersity and photocatalytic activity. The degradation rate of tetracycline and the bactericide rate of E. coli could surpass 90 % and 99 %, which were mainly attributed to the generated O-center dot(2)- and the released Ag ions.

Automated summary

Driven by clean solar energy, photocatalytic technology using mesoporous TiO2 nanoparticles modified with Ag nanocrystals and polydopamine shows high efficiency in degrading organic pollutants and killing pathogenic bacteria.