Hollow Multishell-Structured TiO 2 /MAPbI 3 Composite Improves Charge Utilization for Visible-Light Photocatalytic Hydrogen Evolution.

Interfacial photogenerated charge separation and transport have demonstrated great influence on photocatalytic performance. Herein, the composite photocatalysts of methylammonium lead iodide perovskite (MAPbI 3 ) in TiO 2 with a hollow multishell structure (HoMS) are designed and synthesized. The results indicate that the heterogeneous interface within the MAPbI 3 /Pt/TiO 2 -HoMS can help enhance the separation of photogenerated charges. HoMSs assembled with multiple shells can not only support large surfaces available for building a heterogeneous interface and photocatalytic reactions but also improve the light absorption capability of photocatalysts. Besides, the thin shell structure can also reduce the transmission distance of carriers so as to hinder charge recombination and improve charge utilization. As a result, samples of MAPbI 3 /Pt/triple-shelled TiO 2 hollow structure displayed a H 2 yield of 6856.2 μmol h -1 g -1 under visible light, which is greatly better than that of bare MAPbI 3 (268.6 μmol h -1 g -1 ).