Porous single-crystalline SrTaO₂N, combining structural homogeneity and high porosity, afford a great promise as an active photocatalyst. The lack of grain boundaries in SrTaO₂N porous single crystals (PSCs) enables fast photocarrier migration from bulk to the surface whilst the high porosity offers adequate accessible surface to perform photocatalytic reactions. In this work, we demonstrate a facile synthesis of SrTaO₂N PSCs via a topotactic conversion route. These SrTaO₂N PSCs deliver exceptional activity and stability for photocatalytic O₂ production from water with a record-breaking apparent quantum efficiency as high as 17.9% at 420 ± 20 nm. Overall water splitting with H₂/O₂ equals 2 has also been attained in a Z-scheme system employing SrTaO₂N PSCs as the O₂-evolution moiety. These results signify a paradigm to improve photocatalytic performance based on PSCs, which extends the toolbox to achieve efficient solar water splitting over conventional photocatalysts.

多孔单晶 SrTaO ₂ N 结合了结构均匀性和高孔隙率，有望作为活性光催化剂。SrTaO ₂ N 多孔单晶 (PSC) 中缺乏晶界，使得光载流子从本体快速迁移到表面，同时高孔隙率提供了足够的可接近表面来进行光催化反应。在这项工作中，我们展示了通过拓扑转化路线轻松合成 SrTaO ₂ N PSC。这些 SrTaO ₂ N PSC 为从水中光催化 O ₂生产提供了卓越的活性和稳定性，在 420 ± 20 nm 处具有高达 17.9% 的创纪录的表观量子效率。H ₂ /O整体水分解在采用 SrTaO ₂ N PSC 作为 O ₂释放部分的 Z 方案系统中也已实现₂等于 2 。这些结果标志着基于 PSC 提高光催化性能的范例，它扩展了工具箱以实现比传统光催化剂更有效的太阳能水分解。