Engineering Polarization in the Ferroelectric Electrocatalysts to Boost Water Electrolysis. (28th November 2022)

• Record Type: Journal Article
• Authors: Li, Xiaoning; Du, Yumeng; Ge, Liangbing; Hao, Chongyan; Bai, Ying; Fu, Zhengping; Lu, Yalin; Cheng, Zhenxiang
• Is Part Of: Advanced functional materials. Volume 33:Number 6(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-11-28
• Subjects: band structures -- ferroelectricity -- metallic states -- polarization -- tetragonal tungsten bronze -- water electrolysis; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202210194
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Water splitting is the most important process for making green hydrogen. The positive effects of ferroelectric polarization in various kinds of water splitting are well recognized, but the study of electrocatalytic water splitting is still in its infancy. Herein, a family of intrinsic ferroelectrics with a flexible tetragonal tungsten bronze structure is chosen to accommodate oxygen evolution reaction (OER) active sites together with its freedom for tuning the ferroelectric polarization. It is found that the OER performance is positively correlated with the ferroelectric polarization, with a significant reduction in the overpotential of ≈40 mV at 10 mA cm −2, coming from two trade‐off effects, i.e., enhancement of the surface adsorption and band tilting for fast electron transfer. This study not only fills the gap between electrocatalytic water splitting and the band structure but also proposes ferroelectric polarization as a powerful tool to enhance water splitting for clean hydrogen in several ways. Abstract : The oxygen evolution reaction (OER) activity is enhanced by increasing the ferroelectric polarization. It is realized by filling K in the unfilled Tungsten bronze structured Sr0.5 Ba0.5 Nb1.7 Co0.3 O6‐δ . Density functional theory (DFT) calculations and experimental evidences indicate the underlying physics is that the ferroelectric polarization has two trader‐off effects on OER: enhancing the surface adsorption and the band‐tilting for fast electron transfer.