Surface/Interfacial Engineering of Inorganic Low-Dimensional Electrode Materials for Electrocatalysis

Exploitation of highly active and cost-effective electrode materials for the design of new types of renewable energy storage and conversion systems has been tremendously stimulated by the higher attention being paid to global energy security and invention of alternative clean sustainable energy technologies. Low-dimensional solid materials with special atomic and electronic structures are deemed desirable platforms for establishing clear relationships between surface/interface structure characteristics and electrocatalytic activity, representing enormous potential in the pursuit of high-performance electrocatalysts. Recent achievements revealed that surface and interfacial atomic engineering is capable of achieving novel physical and chemical properties as well as superior synergistic effects in inorganic low-dimensional nanomaterials for electrocatalysis. Compared to bulk counterparts, the electronic structure in the surface of inorganic low-dimensional nanomaterials is more sensitive to and can thus be regulated more easily by surface and interfacial modification strategies, resulting in greatly optimized electrocatalytic performance. In this Account, we focus on recent progress in surface and interfacial modification strategies to efficaciously engineer the electrocatalytic performance of inorganic low-dimensional electrode materials. We summarize several important regulation strategies of dimensional confinement, incorporation, surface reconstruction, interface modulation, and defect engineering, which immensely optimize the spin configuration, electrical conductivity, catalytic active site exposure, and reaction energy barrier of inorganic electrode material. At dimensionally confined atomic-scale thickness, more surface-facet atoms are exposed as active sites, which provide an ideal platform for applying surface incorporation and defect engineering, subsequently producing more catalytic active sites and better adsorption free energy for the improvement of catalytic activity. Moreover, regulation of the interfacial character of electrode materials, such as the surface strain, contact area, and bridged bonds, can optimize the electron transfer capacity and reaction kinetics process. On the other hand, once exposed to a strong alkaline solution under oxidizing potentials, the real active layer of electrode materials (such as transition-metal sulfides, nitrides, and phosphides) could be activated by a surface reconstruction strategy, realizing a unique core-shell structure with a highly conductive electron transfer channel inside and highly active catalytic sites outside for electrocatalysis. Based on these points of view, focusing on inorganic low-dimensional electrode materials, the proper choice of surface and interfacial modification strategies would effectively modulate their electrocatalytic activity, realizing unlimited potential applications in promising areas of electrocatalytic water splitting, rechargeable metal batteries, and fuel cells. Overall, we anticipate that surface and interfacial regulation approaches can provide a new understanding of the design of inorganic electrode materials, facilitating the rapid promotion of electrocatalytic performance in electrode materials for electrocatalysis.