Hierarchical BiOCl microflowers with improved visible-light-driven photocatalytic activity by Fe(III) modification

Abstract

Hierarchical BiOCl microflowers have been synthesized by one-step solvothermal method, which are constructed from many thin nanosheets by exposing the highly active highly active {001} facets. Considering the wide band gap of BiOCl microflowers (3.4eV), the amorphous Fe(III) clusters were grafted on the surfaces through a simple impregnation method to extend the photocatalytic activity to the visible light region. The obtained products were characterized by X-ray diffraction, scanning electron and transmission microscopy, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance spectroscopy, nitrogen adsorption–desorption, and electrochemical measurements. It is found that the Fe(III) clusters are just deposited on the surfaces rather than doped in the lattices of BiOCl. The morphologies and crystal structures of BiOCl microflowers thus remain unchanged after modification of Fe(III) clusters. The photocatalytic activity for the decomposition gaseous acetaldehyde can be significantly improved by the modification of Fe(III) clusters under visible light irradiation. The surface Fe(III) clusters play an important role in the interfacial charge transfer for the visible light absorption. Furthermore, together with the strong oxidative holes in the valence band of BiOCl, the Fe(III) clusters can serves as the redox reaction centers for the multi-electron reduction of oxygen molecules, resulting in the full decomposition of acetaldehyde into CO2.