Chapter 10 - Tailoring defects in 2D materials for electrocatalysis

Abstract

Two-dimensional (2D) materials with unique electronic structures, tunable band-gap states and highly exposed surface areas have provided researchers a fertile ground for electrocatalysis. However, the spatial anisotropy and inert basal planes severely hinder charge transport and catalytic conversion efficiency. At this time, three major issues need to be addressed: (i) tuning surface electronic states to optimize the reaction energy barriers; (ii) incorporation of sufficient active sites to improve the surface electrochemical reactivity and (iii) enhancing the electrical conductivity to accelerate electron transport among the reaction interfaces. Defect engineering is an effective strategy to address the above issues by modulating local electronic configurations, and thus triggering catalytic activity of the inert components. In this chapter, we summarize the state-of-the-art advances in defect engineering of 2D materials for electrocatalytic applications, involving hydrogen evolution reaction (HER), oxygen evolution reaction (OER), carbon dioxide reduction reaction (CO2RR), and nitrogen reduction reaction (NRR). Moreover, the electrocatalytic mechanisms on the defective centers are also discussed in depth. Finally, the challenges and opportunities of defect engineering for 2D electrocatalysts are proposed.