Cobalt based nanoparticles supported on two-dimensional materials and their catalytic applications

Abstract

Hybridizing catalysts with supporting materials have been a general strategy to prevent the aggregation of catalysts during catalytic operation. Two-dimensional materials, which meet the requirements for the catalyst supports such as high surface area, abundant functional groups and excellent electrical and mechanical properties, are one of the most promising candidates for the next-generation catalyst supports. In particular, graphene oxide and MXene, which show high conductive behavior, have shown potential for electrochemical applications. However, restacking behavior of two-dimensional materials as a catalyst supports hinders its applications for catalysis. Due to the restacking of the supports during hybridization, non-uniform formation of catalysts can be occurred. In addition, restacking of two-dimensional materials can occur difficulties in infiltration of electrolyte. To overcome the restacking issue of two-dimensional materials catalyst supports, various methods have been introduced. Simple freeze drying method leads to highly dispersed cobalt based nanoparticles on rGO surfaces. rGO structure with high coverage of cobalt based nanoparticles decorated rGO hybrid composites demonstrates excellent catalytic activity and stability toward hydrogen evolution reaction. Also, I have fabricated cobalt phosphide nanoparticle embedded porous MXene film via hybridization with ZIF-67 as a sacrificial spacer. Size controllable ZIF-67 as a cobalt precursor enables hybrid porous film structures with additional functionalities. Freestanding cobalt phosphide / MXene porous hybrid film demonstrates excellent catalytic activity and stability toward hydrogen evolution reaction. My straightforward hybridization method shows compatibility to various applications that requires ideally structured hybrids of metal based nanoparticles supported on two-dimensional catalyst supports.