Antimicrobial and Photocatalytic Abilities of Ag2CO3 Nano-Rods

The rod-like Ag2CO3 particles (2-4 3 0.3-0.6 mm, length 3 diameter) were synthesized in water by the precipitation reaction between AgNO3 and NaHCO3 in the presence of polyvinylpyrrolidone. The X-ray diffraction analysis revealed the co-existence of monoclinic and hexagonal phases of Ag2CO3, without presence of impurities. The band gap energy of Ag-2 CO3 was found to be 1.4 eV from the diffuse reflectance spectra. Photocatalytic ability of Ag2CO3 was tested using degradation reaction of the organic dye methylene blue over the wide range of concentrations, as well as under long run working conditions in repeated cycles. The photocatalytic mechanism was discussed in terms of the relative energetics of valence and conduction band. Antimicrobial efficiency of Ag-2 CO3 in dark was tested against Gram-negative bacteria E. coli. The Ag2CO3 dispersions in the concentration range 0.1-1.0 mg/mL ensured 100% reduction of bacteria cells. Time-dependent measurements revealed that reduction rates of bacteria cells vary in ascending order with the content of Ag2CO3. On the other hand, the observed reduction rates of bacteria cells do not depend on the concentration of coexisting free Ag+ ions (from 2 to 25 mg/L) present in Ag2CO3 dispersion.