Schottky Junctions with Bi Cocatalyst for Taming Aqueous Phase N2 Reduction toward Enhanced Solar Ammonia Production

• Published in: Advanced science Vol. 8; no. 6; pp. 2003626 - n/a
• Main Authors: Huang, Yewei, Zhu, Yisong, Chen, Shuijiao, Xie, Xiuqiang, Wu, Zhenjun, Zhang, Nan
• Format: Journal Article
• Language: English
• Published: Weinheim John Wiley & Sons, Inc 01-03-2021; John Wiley and Sons Inc; Wiley
• Subjects: Efficiency; Investigations; N2 activation; N2 adsorption; Nanoparticles; Photocatalysis; Scanning electron microscopy; Schottky junctions; solar ammonia production; Spectrum analysis; Transmission electron microscopy
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202003626

Solar‐powered N2 reduction in aqueous solution is becoming a research hotspot for ammonia production. Schottky junctions at the metal/semiconductor interface have been effective to build up a one‐way channel for the delivery of photogenerated electrons toward photoredox reactions. However, their applications for enhancing the aqueous phase reduction of N2 to ammonia have been bottlenecked by the difficulty of N2 activation and the competing H2 evolution reaction (HER) at the metal surface. Herein, the application of Bi with low HER activity as a robust cocatalyst for constructing Schottky‐junction photocatalysts toward N2 reduction to ammonia is reported. The introduction of Bi not only boosts the interfacial electron transfer from excited photocatalysts due to the built‐in Schottky‐junction effect at the Bi/semiconductor interface but also synchronously facilitates the on‐site N2 adsorption and activation toward solar ammonia production. The unidirectional charge transfer to the active site of Bi significantly promotes the photocatalytic N2‐to‐ammonia conversion efficiency by 65 times for BiOBr. In addition, utilizing Bi to enhance the photocatalytic ammonia production can be extended to other semiconductor systems. This work is expected to unlock the promise of engineering Schottky junctions toward high‐efficiency solar N2‐to‐ammonia conversion in aqueous phase.
Bi nanoparticles with low HER activity as the cocatalyst for constructing Schottky junctions toward enhancing photocatalytic N2‐to‐ammonia conversion have been reported, which can promote the photocatalytic N2‐to‐ammonia conversion efficiency by 65 times for BiOBr. The viability of Bi for boosting the photocatalytic N2‐to‐ammonia conversion in aqueous phase has also been confirmed in the TiO2 system.