Shiraishi Yasuhiro, Kishimoto Takuya, Tanaka Shunsuke, Hirai Takayuki
Research Center for Solar Energy Chemistry and Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan.
Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University, Suita 565-0871, Japan.
Langmuir. 2022 Jun 14;38(23):7137-7145. doi: 10.1021/acs.langmuir.2c00336. Epub 2022 May 6.
Sunlight-driven photocatalytic dinitrogen (N) fixation with water at ambient conditions is of vital importance for a sustainable energy society. The efficiency of this reaction, however, is still low because of the difficulty in promoting both water oxidation and N reduction reactions. Herein, we report that a high-phosphorus-doped carbon nitride with surface nitrogen vacancies (PCN(V)) synthesized by thermal condensation under a hydrogen (H) atmosphere using phosphorus oxide (PO) as a phosphorus source efficiently promotes N fixation. The large numbers of the doped P atoms on the PCN(V)-PO catalysts enhance the oxidation of water, while the N vacancies reduce N, facilitating efficient ammonia (NH) generation with an apparent quantum yield at 420 nm of 3.4%. Simulated sunlight illumination of the catalyst in water under N bubbling produces NH with a solar-to-chemical conversion efficiency of 0.16%, which is the highest efficiency among the previously reported powder photocatalysts.
在环境条件下利用阳光驱动光催化将水和氮气（N₂）固定，对于可持续能源社会至关重要。然而，由于难以同时促进水氧化和氮还原反应，该反应的效率仍然很低。在此，我们报告了一种通过在氢气（H₂）气氛下以氧化磷（POₓ）作为磷源进行热缩合合成的具有表面氮空位的高磷掺杂氮化碳（PCN(V)），它能有效地促进氮固定。PCN(V)-PO催化剂上大量掺杂的P原子增强了水的氧化，而氮空位则促进了N₂的还原，从而以420 nm处3.4%的表观量子产率促进了氨（NH₃）的高效生成。在氮气鼓泡下，该催化剂在水中进行模拟阳光照射时，氨的太阳能到化学能的转换效率为0.16%，这是此前报道的粉末光催化剂中最高的效率。
