Bismuth silicate photocatalysts with enhanced light harvesting efficiency by photonic crystal

Bismuth silicate (Bi2SiO5 and Bi12SiO20, BSO) films were aimed to grow uniformly on SiO2 photonic crystal (SPC) via spin-coating. The as-prepared BSO-SPC exhibited better photocatalytic decomposition of Rhodamine B (RhB) than that of the ordinary BSO film under ultraviolet (UV) irradiation. The improvement of photocatalytic activity of BSO can be attributed to the enhancement of light harvesting efficiency by SPC. The results show that the photon localization of SPC plays an important role in enhancing the light absorption of BSO. The influences of the particle diameter of SiO2, the thickness of both SPC and BSO layer on the photon localization of SPC were investigated. This work provides a simple method to improve the light harvesting efficiency of photocatalyst and extends the application of photonic crystal. In addition, the recovery and reuse of immobilized BSO-SPC photocatalyst make it more suitable for practical application. •Photonic crystals can improve the light absorption efficiency of photocatalysts.•Photonic band gap plays an important role in improving photocatalytic performance.•The immobilized photocatalyst can be recycled without secondary pollution.