Key Laboratory of Energy Materials Chemistry, Ministry of Education, Key Laboratory of Advanced Functional Materials, Autonomous Region, Institute of Applied Chemistry, Xinjiang University, Urumqi, Xinjiang, 830046, P.R. China.
Chemistry. 2018 Sep 20;24(53):14111-14118. doi: 10.1002/chem.201803244. Epub 2018 Sep 7.
To gain in-depth insights into the relevant exposed crystal planes for the photocatalytic performance of perovskite-structured oxides, SrSnO nanocrystals with different microstructures were synthesized and their photocatalytic activity for the degradation of simulated dye was investigated. The as-obtained orthorhombic SrSnO nanorods with exposed {001} crystal planes showed higher photocatalytic activity for decomposing methylene blue than that of SrSnO nanoribbons with exposed {111} crystal planes. The surface atomic configurations revealed that the quantity of SnO 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 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 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.
为了深入了解钙钛矿结构氧化物光催化性能的相关暴露晶面，我们合成了具有不同微观结构的 SrSnO 纳米晶体，并研究了它们对模拟染料降解的光催化活性。所获得的具有暴露的{001}晶面的正交 SrSnO 纳米棒比具有暴露的{111}晶面的 SrSnO 纳米带具有更高的光催化分解亚甲基蓝活性。表面原子构型表明，{001}晶面的 SnO 覆盖层的数量略大于{111}晶面的数量，这导致 SrSnO 纳米棒的暴露{001}晶面在光催化过程中表现出更好的活性，因为更少的晶格缺陷作为光生载流子的陷阱，可以减少光激发电子和空穴的复合。这源于晶面距离的缩小和晶胞参数的微小变化；晶轴变短，晶格应变值变小。结果，SrSnO 纳米晶体在后处理条件下表现出不同的表面行为，并表现出光催化性能的变化。本研究结果强调了在评估三元金属氧化物的光催化性能时，探测表面晶面性质的重要性。
