Strontium titanate nanocubes assembled on mesoporous graphitic carbon nitride (SrTiO3/mpg-C3N4): preparation, characterization and catalytic performance

Abstract

This study is a report on successful synthesis of strontium titanate (SrTiO3) nanocubes using a conventional hydrothermal method, their assembly on mesoporous graphitic carbon nitride (mpg-C3N4) to yield novel SrTiO3/mpg-C3N4 nanocomposites, as well as sonocatalyst performance of SrTiO3/mpg-C3N4 to eliminate basic violet 10 (BV10) as a model pollutant from aqueous solutions. To this end, the structure of as-synthesized SrTiO3/mpg-C3N4 nanocomposites was characterized through TEM, HR-SEM, EDS, XRD, FTIR, BET, PI, and UV-vis DRS analyses. To manifest the sonocatalytic performance of SrTiO3/mpg-C3N4 nanocomposites, the main operating parameters such as sonocatalyst dosage, solute concentration, ultrasonic power, initial pH, and reaction time span for the elimination of BV10 were also examined. The best sonocatalytic performance of 80% was further achieved using 0.3 g L-1 sonocatalyst, 10 mg L-1 BV10, and an ultrasonic power of 240 W at pH = 5 (natural) in 120 min of reaction time. The removal rate constant of BV10 via US/SrTiO3/mpg-C3N4 system was 0.0146 min(-1), almost 12 times higher than that achieved by the only ultrasonic process. According to these results, the kinetics of dye elimination system could be determined by the use of pseudo-first-order kinetic model and scavenging compounds also exerted the following adverse effects on the sonocatalytic efficiency in the order of EDTA-2Na < BQ< t-BuOH. Moreover, a mechanism was proposed for the elimination of BV10 in the presence of SrTiO3/mpg-C3N4 nanocomposites under the sonocatalytic system. Finally, the reusability test of SrTiO3/mpg-C3N4 nanocomposites in the BV10 removal revealed that nearly 10% drop occurred after the five successive cycles.