Recent progress in two-dimensional Nb2C MXene for applications in energy storage and conversion

•Characteristic structural, optical, and electronic properties of Nb2C MXenes are described.•Recent progresses in the use of 2D Nb2C for various energy storage devices are summarized.•Design, properties, and prospects of Nb2C-based composite catalyst for hydrogen evolution reaction are explored.•The current state of synthesis methods for Nb2C MXenes are presented.