Book excerpt: Innovation through specific and rational design and functionalization has led to the development of a wide range of mesoporous materials with varying morphologies (hexagonal, cubic, rod-like), structures (silicates, carbons, metal oxides), and unique functionalities (doping, acid functionalization) that currently makes this field one of the most exciting in materials science and energy applications. This book focuses primarily on the rapid progress in their application in energy conversion and storage technologies, including supercapacitor, Li-ion battery, fuel cells, solar cells, and photocatalysis (water splitting) and will serve as a valuable reference for researchers in the field