Core-shell Bi-containing spheres and TiO2 nanoparticles co-loaded on kaolinite as an efficient photocatalyst for methyl orange degradation

Improving the efficiency/cost ratio is the key to the practical application of photocatalysts. Using cheap minerals as carriers is an effective means to improve the efficiency/cost ratio of photocatalysts. Here, kaolinite was used to co-load TiO 2 nanoparticles and Bi containing core-shell spheres forming the composites with excellent photocatalytic performance. The rate constant per unit mass of TiO 2 in the optimal sample reached 18 times that of TiO 2 . Kaolinite plays important roles in promoting photocatalytic activity by improving the dispersion of TiO 2 and the adsorption of O 2 molecules and MO anions, besides the type-II energy band alignment of TiO 2 and Bi x O y .