Recent Progress of Amorphous Nanomaterials

Abstract

Amorphous materials are metastable solids with only short-range order at the atomic scale, which results from local intermolecular chemical bonding. The lack of long-range order typical of crystals endows amorphous nanomaterials with unconventional and intriguing structural features, such as isotropic atomic environments, abundant surface dangling bonds, highly unsaturated coordination, etc. Because of these features and the ensuing modulation in electronic properties, amorphous nanomaterials display potential for practical applications in different areas. Motivated by these elements, here we provide an overview of the unique structural features, the general synthetic methods, and the potential for applications covered by contemporary research in amorphous nanomaterials. Furthermore, we discussed the possible theoretical mechanism for amorphous nanomaterials, examining how the unique structural properties and electronic configurations contribute to their exceptional performance. In particular, the structural benefits of amorphous nanomaterials as well as their enhanced electrocatalytic, optical, and mechanical properties, thereby clarifying the structure−function relationships, are highlighted. Finally, a perspective on the preparation and utilization of amorphous nanomaterials to establish mature systems with a superior hierarchy for various applications is introduced, and an outlook for future challenges and opportunities at the frontiers of this rapidly advancing field is proposed.

A critical review on amorphous–crystalline heterostructured electrocatalysts for efficient water splitting

“…This is particularly useful for creating amorphous–crystalline materials that require specific inorganic phases incorporated into the structure. 67 In summary, the hydrothermal method's ability to provide controlled synthesis conditions, uniform particle sizes, enhanced reactivity, and potential for phase transformations make it a valuable technique for developing amorphous–crystalline materials with tailored properties.…”

How Amorphous Nanomaterials Enhanced Electrocatalytic, SERS, and Mechanical Properties

“…In addition to the direct synthesis of amorphous nanomaterials to promote the existing electrocatalytic activity of crystalline counterparts, the in situ self-reconstruction of amorphous species produced from the crystal during catalysis has been found to be a key to electrocatalysis . It is widely believed that, even for a crystal catalyst, the reconstructed amorphous structure is considered to be the real active phase that is advantageous to the catalytic process. − Thus, amorphization could also bring new properties to inactive traditional crystal materials. For example, unlike the layered hydroxides, which are well-known to be excellent active materials for the OER, some lamellar materials show poor intrinsic activity and electronic conductivity, resulting in inferior catalytic performance.…”

Interface Engineering for the Enhanced Antipoisoning Property of Oxygen Reduction Reaction

“…Interface engineering of electrocatalysts can effectively balance the adsorption and desorption of reactants/reaction intermediates on the catalyst surface, as well as enhance the transportation of intermediates and electrons/adsorbents, which would significantly be promoting the electrochemical activity and selectivity. − It follows the fact that constructing heterostructures with abundant interfaces is one of the effective approaches to achieving excellent intrinsic electrocatalytic performance. Notably, compared to crystalline materials, amorphous counterparts with a disordered atomic arrangement possess abundant defects and unsaturated coordination sites, which could provide abundant active sites and significantly enhance the electrocatalytic activity. − Nevertheless, amorphous materials usually have limited electrical conductivity, resulting in additional energy barriers and decreased performance . Therefore, constructing a crystalline–amorphous interface can enhance the electrical conductivity while ensuring the abundance of defect sites, which is an efficient approach to boosting the catalytic performance.…”