A top-down strategy for amorphization of hydroxyl compounds for electrocatalytic oxygen evolution

Shangheng Liu,Yong Xu,Ling Li,Qi Shao,Jyh-Fu Lee,Bolong Huang,Zhiwei Hu,Ying Zhang,Shize Geng,Yu-Hong Lai,Ying-Hao Chu,Guomian Ren,Xiaoqing Huang

doi:10.1038/s41467-022-28888-3

Abstract

Amorphous materials have attracted increasing attention in diverse fields due to their unique properties, yet their controllable fabrications still remain great challenges. Here, we demonstrate a top-down strategy for the fabrications of amorphous oxides through the amorphization of hydroxides. The versatility of this strategy has been validated by the amorphizations of unitary, binary and ternary hydroxides. Detailed characterizations indicate that the amorphization process is realized by the variation of coordination environment during thermal treatment, where the M–OH octahedral structure in hydroxides evolves to M–O tetrahedral structure in amorphous oxides with the disappearance of the M–M coordination. The optimal amorphous oxide (FeCoSn(OH)6-300) exhibits superior oxygen evolution reaction (OER) activity in alkaline media, where the turnover frequency (TOF) value is 39.4 times higher than that of FeCoSn(OH)6. Moreover, the enhanced OER performance and the amorphization process are investigated with density functional theory (DFT) and molecule dynamics (MD) simulations. The reported top-down fabrication strategy for fabricating amorphous oxides, may further promote fundamental research into and practical applications of amorphous materials for catalysis.

Highlights

Amorphous materials have attracted increasing attention in diverse fields due to their unique properties, yet their controllable fabrications still remain great challenges
Despite these unique properties of amorphous materials, the wide-scale applications of amorphous materials still remain great challenges due to the following reasons: (1) it is still lack of facile protocols for fabricating amorphous materials; (2) High temperature and pressure may further result in recrystallization of amorphous materials, and the stability of amorphous materials is strongly limited by the working conditions[15,16]
The characteristic peaks in the X-ray diffraction (XRD) pattern are ascribed to CoSn(OH)[6] perovskite hydroxide (PDF: 13–0356) (Fig. 1c)

Summary

Introduction

Amorphous materials have attracted increasing attention in diverse fields due to their unique properties, yet their controllable fabrications still remain great challenges. Amorphous materials have attracted great attention due to their disordered atomic arrangement and unsaturated coordination environment[1,2], which have been widely used in diverse fields including mechanical engineering, catalysis, and magnetic applications[3–5] Compared to their crystalline analogues, amorphous materials consist of continuous random networks instead of periodic structures, and usually display some unique properties[6–8]. Detailed characterizations reveal that the amorphization process experiences the transformation of M–OH octahedron in CoSn(OH)[6] into M–O tetrahedron in amorphous oxide Such strategy can be extended to the fabrications of other binary amorphous oxides (e.g., MgSnOx, CaSnOx, MnSnOx, FeSnOx, ZnSnOx, and CdSnOx) and ternary oxides (e.g., MgCoSnOx, CaCoSnOx, MnCoSnOx, FeCoSnOx, NiCoSnOx, CuCoSnOx, CdCoSnOx, and ZnCoSnOx), being a versatile strategy for the formation of amorphous materials. This work provides a versatile top-down strategy for fabricating amorphous oxides, which may further promote the fundamental researches and practical applications of amorphous materials for catalysis

Methods

Results

Conclusion