Cheng Miao, Si Yitao, Li Naixu, Guan Jie
School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, PRC.
Key Laboratory of Quantum Materials and Devices of Ministry of Education, School of Physics, Southeast University, Nanjing 211189, PRC.
J Am Chem Soc. 2024 Sep 25;146(38):26567-26573. doi: 10.1021/jacs.4c10760. Epub 2024 Sep 6.
Two-dimensional (2D) ferroelectric (FE) materials have exhibited significant prospects for applications in photocatalysis due to their unique properties. However, studies of 2D FE catalysts have been mostly focused on the electric potential difference between different surfaces of out-of-plane-polarized FE materials. Herein, based on ab initio density functional calculations, we investigate the effects of in-plane (IP) polarizations on the photocatalytic water splitting process by considering the existence of charged domain walls (DWs) in the 2D FEs. Our results show that the metallic states at the DWs significantly expand the optical absorption range and improve the absorbance in the visible-light region. The built-in electric field spreading over the FE domains promotes the separation of photogenerated charges by driving the electrons/holes to the positively/negatively charged DWs. The charged DWs can also affect the active sites on the surface and effectively lower the energy barrier during pathways of both hydrogen reduction and water oxidation half reactions. With all of these effects, the charged DWs are shown to play the synergistic role of cocatalysts and effectively enhance the performance of GeS in the photocatalytic water splitting reaction. Our study provides not only a new insight into the applications of 2D FEs but also an effective way for regulating the photocatalytic performance of 2D IP FE materials.
二维（2D）铁电（FE）材料因其独特性能在光催化应用中展现出显著前景。然而，二维铁电催化剂的研究大多集中在面外极化铁电材料不同表面之间的电势差上。在此，基于从头算密度泛函计算，我们通过考虑二维铁电体中带电畴壁（DWs）的存在，研究面内（IP）极化对光催化水分解过程的影响。我们的结果表明，畴壁处的金属态显著拓宽了光吸收范围并提高了可见光区域的吸光度。遍布铁电畴的内建电场通过将电子/空穴驱动至带正电/负电的畴壁来促进光生电荷的分离。带电畴壁还会影响表面的活性位点，并有效降低析氢和水氧化半反应路径中的能垒。综合所有这些效应，带电畴壁在光催化水分解反应中发挥着助催化剂的协同作用，并有效提升了GeS的性能。我们的研究不仅为二维铁电体的应用提供了新的见解，还为调控二维面内极化铁电材料的光催化性能提供了有效途径。
