Efficient photodechlorination of chlorophenols on polarized MZnB5O10 (M = Na and K) nonlinear optical materials

摘要

Charge separation is crucial for increasing the activity of semiconductor-based photocatalysts. In this work, a series of non-centric structure materials: K3ZnB5O10 (KZBO), K2NaZnB5O10 (KNZBO) and Na3ZnB5O10 (NZBO), called nonlinear optical materials, show high activity in the chlorophenols dechlorination under UV-vis light irradiation (lambda >254 nm). The obtained dechlorination efficiency is one order of magnitude higher than that of commercial P25 TiO2 catalyst under same reaction conditions. Such materials possess a spontaneous polarization arising from the displacement of the center of the positive and negative charges, providing a driving force for the separation of photogenerated electrons and holes and thereby mitigating the effect of charge recombination as confirmed by Kelvin probe force microscopy. The present work implies that the nonlinear optical materials hold promise in degradation of organic chlorinated pollutants. (C) 2015 Elsevier B.V. All rights reserved.