Enhanced Charge Separation and Transfer Capacity of Heterojunctions by Constructing Homojunctions for Visible Light Photocatalytic Degradation of Toluene

This work presents a new strategy to improve the charge separation and transfer capability for the photocatalytic toluene mineralization by the synergistic effect of homophase junction and type-II heterojunction. The homophase junction is constructed by the slight difference of energy structure between anatase titanium dioxide with different particle sizes around 16 (denotes as A1) and 26 (denotes as A2) nm, showing a significant enhancement in the charge separation and transfer of heterojunction. The physicochemical and photoelectrochemical properties of the as-synthesized materials are investigated by several technologies such as X-ray diffractometer (XRD), electron microscopies and X-ray photoelectron spectroscopy (XPS). The improved photocatalytic activity of 60-AMCr (z-AMCr, z is the amount of A2 loaded on the compounds of A1 and MCr) compared to 40-AMCr and 80-AMCr is assigned to the balance of contact area at the homophase junction interface and light-harvesting capacity of the material. In comparison to heterophase junction, homophase junction displays significant enhancement in the presence of built-in electric field. Additionally, the degradation pathway in the degradation toluene is investigated via in situ infrared method in detail.

Automated summary

This work presents a new strategy to improve the charge separation and transfer capability for the photocatalytic toluene mineralization by the synergistic effect of homophase junction and type-II heterojunction. The homophase junction is constructed by the slight difference of energy structure between anatase titanium dioxide with different particle sizes around 16 (denotes as A1) and 26 (denotes as A2) nm, showing a significant enhancement in the charge separation and transfer of heterojunction. The physicochemical and photoelectrochemical properties of the as-synthesized materials are investigated by several technologies. Additionally, the degradation pathway in the degradation toluene is investigated via in situ infrared method in detail.