Zhang Qiong, Li Qin, Li Heng, Shi Xiangli, Zhou Yimeng, Ye Qianjin, Yang Ran, Li Di, Jiang Deli
Institute for Energy Research, Jiangsu University, Zhenjiang 212013, China.
School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, China.
Inorg Chem. 2023 Jul 31;62(30):12138-12147. doi: 10.1021/acs.inorgchem.3c01741. Epub 2023 Jul 17.
The photocatalytic fixation of N is a promising technology for sustainable production of ammonia, while the unsatisfactory efficiency resulting from the low electron-transfer rate, narrow light absorption range, and limited active sites of the photocatalyst seriously hinder its application. Herein, we designed a noble metal-free Schottky junction photocatalyst constructed by g-CN nanosheets with N vacancies (V-CN) and metallic NiB nanoparticles (NiB/V-CN) for N reduction to ammonia. The ammonia yield rate over the optimized NiB/V-CN is 7.68 mM g h, which is 6.7 times higher than that of pristine CN (1.15 mM g h). The superior photocatalytic N fixation performance of NiB/V-CN can be attributed not only to the formation of Schottky junctions between NiB and V-CN, which facilitates the migration and separation of photogenerated electrons, but also to the incorporation of V into g-CN, which enhances visible light absorption and improves electrical conductivity. More importantly, NiB nanoparticles can act as the cocatalyst, which provide more active sites for the adsorption and activation of N, thereby improving the N reduction activity. This work provides an effective strategy of designing noble metal-free-based cocatalyst photocatalyst for sustainable and economic N fixation.
光催化固氮是一种很有前景的可持续生产氨的技术，然而，由于光催化剂的电子转移速率低、光吸收范围窄以及活性位点有限导致的效率不尽人意，严重阻碍了其应用。在此，我们设计了一种无贵金属的肖特基结光催化剂，该催化剂由具有氮空位的g-CN纳米片（V-CN）和金属NiB纳米颗粒（NiB/V-CN）构成，用于将氮还原为氨。优化后的NiB/V-CN的氨产率为7.68 mM g h，比原始CN（1.15 mM g h）高6.7倍。NiB/V-CN优异的光催化固氮性能不仅归因于NiB和V-CN之间形成的肖特基结，这有利于光生电子的迁移和分离，还归因于V掺入g-CN中，这增强了可见光吸收并提高了电导率。更重要的是，NiB纳米颗粒可以作为助催化剂，为氮的吸附和活化提供更多活性位点，从而提高氮还原活性。这项工作为设计用于可持续和经济固氮的无贵金属基助催化剂光催化剂提供了一种有效策略。
