Liu Ping, Liang Teng, Li Yutong, Zhang Ziqing, Li Zhuo, Bian Ji, Jing Liqiang
Key Laboratory of Functional Inorganic Materials Chemistry (Ministry of Education), School of Chemistry and Materials Science, International Joint Research Center and Lab for Catalytic Technology, Heilongjiang University, Harbin, 150080, P. R. China.
Nat Commun. 2024 Oct 25;15(1):9224. doi: 10.1038/s41467-024-53482-0.
Graphitic carbon nitride (g-CN) has gained increasing attention in artificial photosynthesis of HO, yet its performance is hindered by sluggish oxygen reduction reaction (ORR) kinetics and short excited-state electron lifetimes. Here we show a B-doped g-CN (BCN) tailored with coordinatively unsaturated FeOOH and CoO clusters for HO photosynthesis from water and oxygen without sacrificial agents. The optimal material delivers a 30-fold activity enhancement compared with g-CN under visible light, with a solar-to-chemical conversion efficiency of 0.75%, ranking among the forefront of reported g-CN-based photocatalysts. Additionally, an electron transfer efficiency reaches 34.1% for the oxygen reduction reaction as revealed by in situ microsecond transient absorption spectroscopy. Experimental and theoretical results reveal that CoO initiates hole-water oxidation and prolongs the electron lifetime, whereas FeOOH accepts electrons and promotes oxygen activation. Intriguingly, the key to the direct one-step two-electron reaction pathway for HO production lies in coordinatively unsaturated FeOOH to adjust the Pauling-type adsorption configuration of O to stabilize peroxide species and restrain the formation of superoxide radicals.
石墨相氮化碳（g-CN）在光催化分解水制过氧化氢（H₂O₂）领域受到了越来越多的关注，但其性能受到缓慢的氧还原反应（ORR）动力学和较短的激发态电子寿命的限制。在此，我们展示了一种通过配位不饱和的FeOOH和CoO团簇修饰的硼掺杂g-CN（BCN），用于在无牺牲剂的情况下从水和氧气中光催化合成H₂O₂。与g-CN相比，这种优化后的材料在可见光下活性提高了30倍，太阳能到化学能的转换效率为0.75%，在已报道的基于g-CN的光催化剂中处于前沿水平。此外，原位微秒瞬态吸收光谱表明，该材料在氧还原反应中的电子转移效率达到34.1%。实验和理论结果表明，CoO引发空穴-水氧化并延长电子寿命，而FeOOH接受电子并促进氧的活化。有趣的是，直接一步两电子反应途径生成H₂O₂的关键在于配位不饱和的FeOOH调整O的鲍林型吸附构型以稳定过氧化物物种并抑制超氧自由基的形成。
