Correlation between particle size of Bi2O3 nanoparticles and their photocatalytic activity for degradation and mineralization of atrazine

Herein, we report a systematic investigation into the role of particle size of Bi2O3 nanoparticles on their photocatalytic activity. The range of particle size is from 11 to 27 nm. Using degradation and mineralization of atrazine under UVA light as probe reactions, we show that photocatalytic activity is very sensitive to particle size. A slight difference in particle size leads to a significant difference in photocatalytic activity. Photocatalytic activity does not linearly increase with increasing particle size. Within 1 h of 2.42 W/m(2) UVA irradiation at pH 6, the degradation efficiency for 5 mg/L of atrazine using 1 g/L of Bi2O3 with an average particle size of 11,16.7, 20.1 and 26.8 nm is 84.9, 87.5, 92.1 and 75.5%, respectively. There is an optimum particle size, which is found to be 20.1 nm, as the best compromise between surface area and surface recombination. With these results, the particle size effect should be really taken into account so as to achieve appreciable performance for further development of photo catalytic system involving Bi2O3. (C) 2017 Elsevier B.V. All rights reserved.