Design of 3D WO3/h-BN nanocomposites for efficient visible-light-driven photocatalysis

Abstract

3D WO3 nanoparticle/h-BN nanosheet composites (WO3/BN) have been designed and fabricated by a simple in situ one-step calcination method. By homogeneous dispersing WO3 on graphene-like BN nanosheets, the as-fabricated WO3/BN nanocomposites provided large surface area with more active sites, and a significant red shift of absorption edge from 310 nm to 800 nm containing the full visible optical spectrum absorption was realized, which was favorable for enhancing the absorption of the visible light area and taking full advantages of visible light utilization. Subsequently, the as-fabricated nanocomposites were employed for photocatalytic study under visible light illumination, and the 20% WO3/BN sample exhibited the highest photocatalytic activity for Rhodamine B (RhB) degradation with the degradation efficiency of ∼92%. Additionally, the WO3/BN nanocomposites have the excellent degradation efficiency toward Ciprofloxacin (CIP) that was hard to be degradation under visible light illumination, which could be ascribed to the homodisperse WO3 with more effective active sites for the target pollutants and a synergistic effect between the WO3 and graphene-like BN. ESR and the radical trapping experiments were further conducted to study the degradation mechanism, and a possible reaction mechanism was proposed, which revealed that the greatly improved photocatalytic activity was mainly ascribed to the high electron-hole separation and transfer efficiency. Our exploration of graphene-like BN modified with WO3 open a window for the use of other graphene-like BN based composition photocatalysis field.