Open AccessPhotocatalytic inactivation ofEscherichia coliunder UV light irradiation using large surface area anatase TiO2quantum dots
Author(s) -
Faheem Ahmed,
Chawki Awada,
Sajid Ali Ansari,
Abdullah Aljaafari,
Adil Alshoaibi
Publication year - 2019
Publication title -
royal society open science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.84
H-Index - 51
ISSN - 2054-5703
DOI - 10.1098/rsos.191444
Subject(s) - anatase , photocatalysis , materials science , crystallinity , absorbance , titanium dioxide , raman spectroscopy , quantum dot , band gap , nanotechnology , specific surface area , nanoparticle , ultraviolet , chemical engineering , particle size , photochemistry , irradiation , optoelectronics , chemistry , optics , chromatography , organic chemistry , catalysis , composite material , physics , engineering , nuclear physics
In this study, high specific surface areas (SSAs) of anatase titanium dioxide (TiO 2 ) quantum dots (QDs) were successfully synthesized through a novel one-step microwave–hydrothermal method in rapid synthesis time (20 min) without further heat treatment. XRD analysis and HR-TEM images showed that the as-prepared TiO 2 QDs of approximately 2 nm size have high crystallinity with anatase phase. Optical properties showed that the energy band gap ( E g ) of as-prepared TiO 2 QDs was 3.60 eV, which is higher than the standard TiO 2 band gap, which might be due to the quantum size effect. Raman studies showed shifting and broadening of the peaks of TiO 2 QDs due to the reduction of the crystallite size. The obtained Brunauer–Emmett–Teller specific surface area (381 m 2 g −1 ) of TiO 2 QDs is greater than the surface area (181 m 2 g −1 ) of commercial TiO 2 nanoparticles. The photocatalytic activities of TiO 2 QDs were conducted by the inactivation of Escherischia coli under ultraviolet light irradiation and compared with commercially available anatase TiO 2 nanoparticles. The photocatalytic inactivation ability of E. coli was estimated to be 91% at 60 µg ml −1 for TiO 2 QDs, which is superior to the commercial TiO 2 nanoparticles. Hence, the present study provides new insight into the rapid synthesis of TiO 2 QDs without any annealing treatment to increase the absorbance of ultraviolet light for superior photocatalytic inactivation ability of E. coli .