Insights into Crystal Facets of Perovskite SrSnO₃ as High‐Performance Photocatalysts toward Environmental Remediation

To gain in‐depth insights into the relevant exposed crystal planes for the photocatalytic performance of perovskite‐structured oxides, SrSnO 3 nanocrystals with different microstructures were synthesized and their photocatalytic activity for the degradation of simulated dye was investigated. The as‐obtained orthorhombic SrSnO 3 nanorods with exposed {001} crystal planes showed higher photocatalytic activity for decomposing methylene blue than that of SrSnO 3 nanoribbons with exposed {111} crystal planes. The surface atomic configurations revealed that the quantity of SnO 2 overlayer on the {001} crystal facets is slightly greater than that on {111} crystal planes, which results in exposed {001} crystal facets of the SrSnO 3 nanorods that can exhibit better activity in the photocatalytic process, due to fewer lattice defects, which act as traps for photogenerated charge carriers to decrease the recombination of photoexcited electrons and holes. This originated from narrowing of the crystal face distance and slight variation of the unit cell parameters; the crystallographic axis became shorter and the value of lattice strain became smaller. As a result, SrSnO 3 nanocrystals exhibited different surface behavior under post‐treatment conditions and exhibited variation in the photocatalytic properties. The findings reported herein highlight the importance of probing the properties of surface facets in the evaluation of the photocatalytic performance of ternary metal oxides.