Fabrication and high photocatalytic performance of noble metal nanoparticles supported on 3DOM InVO4–BiVO4 for the visible-light-driven degradation of rhodamine B and methylene blue

Three-dimensionally ordered macroporous (3DOM) InVO4–BiVO4 (InBi-3D) and its supported noble metal M nanoparticles (xM/InBi-3D; x = 0.08–0.13 wt%; M = Au, Ag, Pd, Pt) were prepared using the polymethyl methacrylate-templating and polyvinyl alcohol- or polyvinyl pyrrolidone-assisted reduction methods, respectively. Physical properties of the materials were characterized by a number of analytical techniques. Photocatalytic activities of the xM/InBi-3D samples were evaluated for the degradation of rhodamine B (RhB), methylene blue (MB), and their mixture. It is found that the as-fabricated samples possessed a surface area of 17–30 m2/g, a M particle size of 2.5–3.8 nm, and a bandgap energy of 2.50–2.56 eV. The xM/InBi-3D photocatalysts showed high activities for the degradation of RhB, MB, and RhB + MB in the presence of a small amount of H2O2 under visible-light irradiation, among which complete degradation of RhB, MB, and RhB + MB was achieved within 50, 90, and 120 min over 0.08 wt% Au/InBi-3D, respectively. The degradation of MB and RhB fellow the zero- and first-order reaction mechanisms with respect to dye concentration, respectively. It is concluded that the high photocatalytic efficiency of the Au-loaded sample in the removal of organic dyes was associated with its high surface area, high-quality 3DOM hierarchical architecture, InVO4–BiVO4 composite, and high dispersion of gold nanoparticles.