Book excerpt: Polyoxometalate-Based Hybrids and their Applications focuses on recent progress in polyoxometalate-based hybrids materials. Chapters present the structure, composition, classification and properties of POMs such as isopolyaions, heteropolyanions, giant and lacunary polyoxometalates and then cover polyoxometalate-based open-frameworks (POM-OFs), include a historical introduction to these compounds, and present their synthetic strategies. The structural diversity and relative applications of POM-OFs is also covered. Other sections delve into synthetic strategies, structural diversity and relative applications of porous polyoxometalate-based metal-organic frameworks. Polyoxometalate-based coordination polymers (POMCPs) and polyoxometalate-based host-guest framework materials are highlighted in final sections. This book is an essential reference for inorganic chemists, biochemists, and material scientists working in academia and industry. - Discusses polyoxometalate-based host-guest framework materials - Includes coverage of polyoxometalates and their environmental applications - Reviews transition metal substituted lacunary polyoxometalates