Antibacterial and photocatalytic activity of hydrothermally synthesized SnO2 doped GO and CNT under visible light irradiation.

Bacterial and dye pollution are major problems with wastewater treatment. An increasing number of photocatalysts are being used in industry to kill bacterial and reduce pollution. In the present study, highly stable SnO2-doped nanocomposites have been prepared successively by a hydrothermal method. The synthesized nanocomposite was characterized using a range of techniques, such as X-ray diffraction, field emission scanning electron microscopy with energy dispersive X-ray spectroscopy and electron probe micro analysis, ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, and high resolution transmission electron microscopy (HR-TEM). The nanocomposites showed significant dose-dependent bactericidal activity in the disc diffusion assay and cell viability test. The S-GO-SnO2 200 μg/mL produced a cell viability of 184.3 ± 11.71 and 172.3 ± 3.05 × 106 CFU/mL for E. coli and P. graminis, respectively. The S-GO-SnO2 showed significant photocatalytic degradation against MB in 120 min. The photocatalyst S-GO-SnO2 showed 159 and 161 × 106 CFU/mL at 150 min in E. coli and P. graminis, respectively. The cells treated with photocatalytic SnO2-doped nanocomposites showed 50% cell death. HR-TEM revealed 50% cell growth inhibition by bacterial damage. This photocatalytic SnO2-doped nanocomposite is a good candidate for treating industrial wastewater treatment contaminated with dyes and bacteria.