Characterizing metal carbide structures: Insights from photoelectron spectroscopy and density functional theory

Abstract

Metal carbides are highly intriguing to researchers due to their diverse properties, including electrical, thermal, magnetic, and mechanical characteristics. They are prized for their high specific surface areas, exceptional biocompatibility, and versatile applications across various fields such as chemical synthesis, catalysis, mechanical components, coatings, electronics, and aerospace materials. Through techniques like photoelectron spectroscopy (PES) and density functional theory (DFT), scientists have extensively studied the geometries, microstructure, stability, charge distribution, electronic properties, and electromagnetic characteristics of metal carbide clusters. These studies have paved the way for the development of new metal−carbon materials at both atomic and macro scales, finding applications in industrial catalysis, high−temperature ceramics, electrode materials, supercapacitors, and even astrochemistry. This review delves into the compositions, methods for structure determination, bonding patterns, and geometric arrangements observed in a wide range of metal-carbide clusters. These clusters, composed of metal atoms bonded to carbon atoms in different ratios and configurations, have been thoroughly investigated to unravel their fundamental properties and potential applications. The goal of this review is to offer a comprehensive overview of our current understanding of the structural characteristics and chemical bonding within metal-carbide clusters, emphasizing their importance in materials science and catalysis. These insights are instrumental in designing novel nano−scale metal−carbide clusters that find utility in creating nanowires, nanotubes, and 2D sheets for various applications like photovoltaic cells, electrodes, batteries, catalysts, and electronic devices.