A novel macro-meso-micro intimate heterogeneous structure constructed 3DOM TiO2/rGO/TiN composite for efficiently solar photocatalysis degradation of organic dye pollutants

The new three-dimensionally ordered macroporous titanium dioxide/reduced graphene oxide/titanium nitride (3DOM TiO2/rGO/TiN) ternary nanocomposites are designed based on the pore structure of 3DOM for efficient photocatalytic dye degradation. A series of structural, optical, and photoelectrochemical characterizations demonstrate that the remarkably improved photocatalytic performance is attributed to the combined effects of macro-meso-micro architecture, abundant reactive sites, improved light response range, and efficient photogenerated charges-holes pair separation and transport. By optimizing the loading amounts of rGO and TiN, 3DOM TiO2/10%rGO/5%TiN nanocomposite exhibits the highest photocatalytic degradation activity, which is 7.4 times higher than 3DOM TiO2. Additionally, the 3DOM TiO2/rGO/TiN ternary photocatalyst shows excellent acid-base resistance and reusability. The mechanism by which 3DOM structure, 2D rGO, and TiN synergy enhance the TiO2 photocatalytic performance was fully revealed comprehensively. This work provides an effective strategy for designing TiO2-base macro-meso-micro intimate heterogeneous structure for photocatalysis degradation of dyes.