Mistry Elan D R, Lubert-Perquel Daphné, Nevjestic Irena, Mallia Giuseppe, Ferrer Pilar, Roy Kanak, Held Georg, Tian Tian, Harrison Nicholas M, Heutz Sandrine, Petit Camille
Institute of Molecular Sciences and Engineering, Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, 82 Wood Lane, London W12 0BZ, United Kingdom.
London Centre for Nanotechnology and Department of Materials, Imperial College London, South Kensington Campus, Prince's Consort Road, London SW7 2BP, United Kingdom.
Chem Mater. 2023 Feb 25;35(5):1858-1867. doi: 10.1021/acs.chemmater.2c01646. eCollection 2023 Mar 14.
A family of boron nitride (BN)-based photocatalysts for solar fuel syntheses have recently emerged. Studies have shown that oxygen doping, leading to boron oxynitride (BNO), can extend light absorption to the visible range. However, the fundamental question surrounding the origin of enhanced light harvesting and the role of specific chemical states of oxygen in BNO photochemistry remains unanswered. Here, using an integrated experimental and first-principles-based computational approach, we demonstrate that paramagnetic isolated OB states are paramount to inducing prominent red-shifted light absorption. Conversely, we highlight the diamagnetic nature of O-B-O states, which are shown to cause undesired larger band gaps and impaired photochemistry. This study elucidates the importance of paramagnetism in BNO semiconductors and provides fundamental insight into its photophysics. The work herein paves the way for tailoring of its optoelectronic and photochemical properties for solar fuel synthesis.
最近出现了一族用于太阳能燃料合成的氮化硼（BN）基光催化剂。研究表明，氧掺杂会生成氮氧化硼（BNO），从而将光吸收扩展到可见光范围。然而，围绕增强光捕获的起源以及BNO光化学中特定氧化学态的作用这一基本问题仍未得到解答。在此，我们采用综合实验和基于第一性原理的计算方法，证明顺磁性孤立的OB态对于诱导显著的红移光吸收至关重要。相反，我们强调了O - B - O态的抗磁性，它会导致不期望的更大带隙和光化学受损。这项研究阐明了顺磁性在BNO半导体中的重要性，并为其光物理提供了基本见解。本文的工作为调整其用于太阳能燃料合成的光电和光化学性质铺平了道路。
