Experimental and theoretical revealing of piezo-photocatalyst Bi2O2CO3 for degradation of ciprofloxacin in water.

ABSTRACT

In this report, we have attempted to experimentally and theoretically reveal a new piezo-photocatalyst Bi2O2CO3 for efficient removal of ciprofloxacin (CIP) from water. Bi2O2CO3 nanoplates were synthesized to evaluate their photocatalytic (irradiation source simulated-sunlight), piezocatalytic (irradiation source ultrasonic) and piezo-photocatalytic (irradiation source simulated-sunlight and ultrasonic) performances for CIP elimination. Under the condition CCIP = 10 mg/L and Ccatalyst = 1 g/L, the piezo-photodegradation rate constant is obtained as kapp = 0.07811 min-1, which surpasses that of photocatalysis (kapp = 0.04686 min-1) and piezocatalysis (kapp = 0.01233 min-1); this phenomenon manifests an obvious piezo-enhanced photocatalytic behavior in terms of the "1 + 1 > 2" principle. The ultrasonic-induced piezoelectric behavior in Bi2O2CO3 nanoplates and involved piezo-photocatalytic mechanism were theoretically elucidated by density functional theory (DFT) and finite-element method (FEM) studies. Additionally, the effects of various factors on the CIP degradation, decomposition mechanism of CIP and toxicity of the decomposition intermediates were also analyzed.