Sono-photodeposition of Ag over sono-fabricated mesoporous Bi2Sn2O7-two dimensional carbon nitride: Type-II plasmonic nano-heterojunction with simulated sunlight-driven elimination of drug

Abstract

The mesoporous Ag/Bi2Sn2O7-C3N4 plasmonic nanophotocatalyst, which was synthesized by the hybridization method of the sono-dispersion and the heat-treatment following with the sono-photodeposition, was applied as an efficient solar-light-driven photocatalyst for degradation of Tetracycline (TC) antibiotic. Also, the Bi2Sn2O7, g-C3N4, Bi2Sn2O7-C3N4, Ag/Bi2Sn2O7 and Ag/C3N4 nanophotocatalysts were synthesized to compare. The characterizations of samples were conducted using XRD, morphology analyses such as FESEM, TEM and AFM, EDX and dot mapping, BET-BJH, FTIR, DRS and pHpzc. The results of morphology analyses showed that about 75.2% of nanoparticles are at the range of 10–20 nm and the minimum and maximum particle sizes were 6.9 nm and 42.2 nm respectively. Moreover, the cubic Ag particles size was about 25.7 nm. Besides, the results of the UV–vis diffuse reflectance spectroscopy analysis illustrated the promotion of the absorption edge of Ag/Bi2Sn2O7-C3N4 (at about 521 nm) following with the decrement of band gap (2.38 eV). The photocatalytic activity of Ag/Bi2Sn2O7-C3N4 was obtained higher than other samples (89.1%) due to Bi2Sn2O7-C3N4 type-II heterojunction, porous structure with the high specific surface area (66 m2/g) owing to the usage of ultrasonic energy and the surface plasmon resonance created using the Ag particle. Moreover, experiments were carried out to investigate the effect of various parameters such as the photocatalyst dosage, initial concentration and pH of TC solution in removing the contaminate molecule from aqueous solution under the light illumination, which was simulated as sunlight . Moreover, the possible elimination mechanism was proposed for pollutant removal.