Surface Na_2CO_3 etching induced activity enhancement of 2D BiOI photocatalyst working under visible light

【摘要】：The visible light photocatalytic activity of two-dimensional(2D) BiOI microplates was intensively enhanced through simply dipping in Na_2CO_3 solutions at room temperature. The X-ray powder diffraction(XRD) and scanning electron microscopy(SEM) investigations suggest that little amount of(BiO)_2CO_3phase was formed on the surface of 2D BiOI via the in situ chemical conversion. The concentration of Na_2CO_3 solutions affected the structure, morphology, light absorption and surface element component of 2D BiOI. The surface loaded(BiO)_2CO_3mainly trapped the photoinduced electrons of BiOI, improved the separation efficiency of photocharges and finally raised the photocatalytic activity of BiOI under visible light(k 420 nm). Furthermore, the product of the as-prepared(BiO)_2CO_3/BiOI displayed excellent stability in the repeated experiment. This study provides a facile way to improve the photocatalytic activity of BiOX(X = Cl, Br, I) by means of surface treatment with Na_2CO_3 solutions.