Preparation and visible-light photocatalytic properties of the floating hollow glass microspheres – TiO2/Ag3PO4 composites

摘要

A novel floating visible-light photocatalyst (HGMs–TiO _(2) /Ag _(3) PO _(4) ) composite was prepared using amino modified low-density hollow glass microspheres (HGMs) as carriers to disperse and support TiO _(2) and Ag _(3) PO _(4) photocatalysts. The surface morphology, crystal structure and optical properties of the HGMs–TiO _(2) /Ag _(3) PO _(4) composites were characterized and the Ag _(3) PO _(4) content on the surface of the microspheres was determined by atomic absorption spectrometry (AAS). Methylene blue (MB) was chose as the organic pollutant to investigate the visible-light catalytic properties of the HGMs–TiO _(2) /Ag _(3) PO _(4) composites. For HGM composite photocatalysts, when the theoretical mass ratio of TiO _(2) to Ag _(3) PO _(4) on the surface of HGMs is 1?:?1.5, the visible-light catalytic activity of the composite is superior to pure Ag _(3) PO _(4) and a TiO _(2) /Ag _(3) PO _(4) photocatalyst with a mass ratio of 1?:?1.5 under the same conditions, due to the increased light-contact area and the photocatalytic active sites, since the TiO _(2) and Ag _(3) PO _(4) particles can be well dispersed on the surface of the floating HGMs. Furthermore, the deposits of TiO _(2) and Ag _(3) PO _(4) on the HGM surface form a heterostructure, facilitating the separation of electron–hole (e ~(?) – h ~(+) ) in the energy band, and elevating the photocatalytic activity and cycle stability of Ag _(3) PO _(4) . This work indicates that floating HGMs–TiO _(2) /Ag _(3) PO _(4) composites could become a promising photocatalyst for organic dye removal due to the low cost and high visible-light responsiveness.