N掺杂FeNi催化剂提升Fe2O3光阳极析氧活性

N-doped FeNi Cocatalysts for Enhancing the OER Activity in Fe2O3 Photoanodes

中文关键词:  太阳能  Fe₂O₃光阳极  N掺杂  FeNi催化剂  水氧化

英文关键词:solar energy  Fe₂O₃ photoanodes  N-doped  FeNi cocatalyst  water oxidation

中文摘要:

      光电催化分解水技术可将太阳能直接转化为清洁、可储存的氢能源, 然而目前光阳极普遍存在析氧动力学缓慢、光生载流子复合快等问题导致太阳能分解水转换效率较低. 我们在Fe₂O₃纳米棒光阳极表面修饰N掺杂FeNi催化剂(Fe₂O₃-FNNO), 在1.23 V时光电流密度达到2.5 mA·cm^-2(AM 1.5G, 100 mW·cm^-2), 相比未修饰Fe₂O₃光阳极性能提升2.5倍(1.0 mA·cm^-2). 进一步研究表明, FeNi催化剂与Fe₂O₃之间的N-O界面键合能够有效促进光生电子-空穴高效分离与转移, 光生空穴快速转移至FeNi催化剂表面活性位, 从而大幅度提高析氧催化活性与稳定性. 该研究工作为构筑高效稳定的Fe₂O₃光阳极提供了新的研究思路.

英文摘要:

      Photoelectrochemical (PEC) catalysis has been perceived as a promising approach in the water splitting, utilizing the drive of sunlight to yield evironmentally and storable hydrogen energy. However, the photoanodes were restricted in sluggish water oxidation kinetics and high charge recombination, resulting in low energy conversion. Herein, we demonstrated the N-doped FeNi cocatalysts over the surface of pristine Fe₂O₃ photoanodes (Fe₂O₃-FNNO), whose photocurrent density could reach to 2.5 mA·cm^-2 at 1.23 V vs. RHE (reversible hydrogen electrode, AM 1.5G). Further experimental and characterization studies reveal that the reduction properties of NH₃ and formation of N―O bond could enhance the ratio of Fe²⁺ and Ni³⁺ in FeNi cocatalysts to offer more active sites in the PEC water splitting. Thus, this work provides a potential and promising route to developing high-performance Fe₂O₃ photoanodes.