Perovskite‐type LaNbON₂ has the longest wavelength onset of visible light absorption—up to approximately 740 nm—among (oxy)nitrides based on transition metals Ti, Ta, and Nb. Water oxidation using visible‐light‐responsive LaNbON₂ is challenging because the synthesis of the oxynitride has rarely been studied. Herein, we report the synthesis of small LaNbON₂ particles and their size effect on photocatalytic water oxidation under visible light illumination. The small scheelite‐type LaNbO₄, prepared by a polymerized complex method, was transformed into less‐defective LaNbON₂ during nitridation as compared with that nitrided from LaNbO₄ via a solid‐state reaction method. The small LaNbON₂ particles, capable of absorbing intense visible light 700 nm above, improved the O₂ evolution during 5 h of water oxidation under 300 W Xe light irradiation (λ > 420 nm). This enhancement was attributed to the size reduction of LaNbON₂ particles, leading to increased surface area and encouragement of mild nitridation.

中文翻译：

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LaNbON2颗粒在可见光照射下增强光催化水氧化的尺寸控制

钙钛矿型LaNbON ₂在基于过渡金属Ti，Ta和Nb的（氧）氮化物中，可见光吸收的波长开始最长，可达约740 nm。使用可见光响应的LaNbON _2进行水氧化具有挑战性，因为很少研究氧氮化物的合成。在这里，我们报告了小的LaNbON ₂颗粒的合成及其尺寸对可见光照射下光催化水氧化的影响。与通过固相反应法从LaNbO ₄中氮化的氮化硅相比，通过聚合络合方法制备的小型白钨矿型LaNbO _4可以在氮化过程中转化为缺陷较少的LaNbON ₂。小兰伯_2个能够吸收700 nm以上高强度可见光的颗粒改善了在300 W Xe光照射（λ> 420 nm）下水氧化5 h期间O _2的释放。这种增强归因于LaNbON ₂颗粒的尺寸减小，从而导致表面积增加和促进了轻度的氮化。