Liquid elementary metals and alloys: Synthesis, characterization, properties, and applications

Liquid elementary metals and alloys at room or low temperatures have recently been attracting great attention due to their combined feature of metallic as well as the liquid state in nature, which can be particularly important in future electronics, catalysts, and sensors. In addition, their surface skin is highly sensitive to the ambient environment, providing highly flexible platforms for accommodating surface modification and chemical reactions to extend their implementation. In this review, the synthesis routes and characterization techniques of liquid elementary metals and alloys in both forms of bulk and micro/nano-scale droplets are critically discussed. The corresponding electrical, chemical, electrochemical, mechanical, and thermal properties of either the bulk or surface states are summarized. Furthermore, their implementations in electronics, catalysis, energy storage, cooling, radio frequency (RF) and biomedical devices are categorized and reviewed. Finally, the current challenges and prospects of liquid metal research are provided.