Space-confined growth of halide perovskite nanocrystals for enhanced photocatalytic hydrogen evolution

Abstract

Halide perovskites, as emerging semiconductor materials, exhibit great potential in photocatalytic hydrogen evolution. However, perovskite powders prepared through the conventional co-precipitation method typically form large-sized particles with diameters of several tens of micrometers, resulting in low specific surface area and limited active sites, which seriously compromise their catalytic efficiency. Herein, a spatially confined growth method is developed to grow small-sized mixed halide perovskite FAPbBr_3-xI_x (FA = CH(NH₂)₂⁺) nanocrystals within MCM-41 molecular sieve for photocatalytic hydroiodic acid splitting. This developed method significantly increases the specific surface area, provides more reaction sites, and promotes the separation of carriers for the perovskite nanocrystal. When loading with Pt as the cocatalyst, 40 % MCM-41@FAPbBr_3-xI_x composite demonstrates excellent photocatalytic H₂ evolution activity of 2260 μmol h⁻¹. This work presents an inspiring advancement in confined growth tactics for perovskite nanocrystals to achieve efficient photocatalytic hydrogen evolution.