Liu Lingmei, Sun Wuzhu, Yang Weiyi, Li Qi, Shang Jian Ku
Environment Functional Materials Division, Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, P. R. China.
Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Sci Rep. 2016 Feb 16;6:20878. doi: 10.1038/srep20878.
Most photocatalysts only function under illumination, while many potential applications require continuous activities in dark. Thus, novel photocatalysts should be developed, which could store part of their photoactivity in "memory" under illumination and then be active from this "memory" after the illumination is turned off for an extended period of time. Here a novel composite photocatalyst of SnO2 nanoparticle-decorated Cu2O nanocubes is developed. Their large conduction band potential difference and the inner electrostatic field formed in the p-n heterojunction provide a strong driving force for photogenerated electrons to move from Cu2O to SnO2 under visible light illumination, which could then be released to react with O2 in dark to produce H2O2 for its post-illumination activity. This work demonstrates that the selection of decoration components for photocatalysts with the post-illumination photocatalytic "memory" could be largely expanded to semiconductors with conduction band potentials less positive than the two-electron reduction potential of O2.
大多数光催化剂仅在光照下发挥作用，而许多潜在应用需要在黑暗中持续保持活性。因此，应开发新型光催化剂，其能够在光照下将部分光活性存储在“记忆”中，然后在光照关闭较长时间后从该“记忆”中恢复活性。本文开发了一种新型的二氧化锡纳米颗粒修饰的氧化亚铜纳米立方复合光催化剂。它们的大导带电位差以及在p-n异质结中形成的内静电场为光生电子在可见光照射下从氧化亚铜迁移到二氧化锡提供了强大驱动力，这些电子随后可在黑暗中释放出来与氧气反应生成过氧化氢，以实现其光照后的活性。这项工作表明，具有光照后光催化“记忆”的光催化剂的修饰组分选择范围可大幅扩展至导带电位比氧气的双电子还原电位更正的半导体。
