Advancements in sustainable phase change materials: Valorizing waste for eco-friendly applications

In recent years, the topics of energy storage and transformation have sparked tremendous interest and popularity, owing to a growing worldwide awareness of the importance of sustainable development. Phase change materials (PCMs) are one of those appealing materials for efficiently harvesting thermal energy from renewable energy sources. To address the challenge of economic viability which hinders the widespread utilization of PCMs, there is an urgent need to investigate waste valorization for developing efficient and eco-friendly PCMs for diverse applications. This paper provides an overview of the most recent advancements over the past five years in the creative utilization of waste materials as sustainable raw materials for the synthesis of PCMs. Diverse waste materials sources, such as bio-based materials, plastics, industrial by-products, and construction site waste, are explored as potential materials for incorporation into PCM composites. We demonstrate the effectiveness of converting these waste materials into high-value PCMs, contributing to a circular economy and promoting sustainability. For each type of PCMs studied, we provide critical performance metrics, such as thermal properties, durability, and environmental impact. Specifically, the potential application of waste/PCM composites in building materials are also highlighted. [Display omitted] •Valorized wastes can be used to develop eco-friendly phase change materials.•A diverse range of waste materials sources are explored for utilization.•Waste materials can serve as robust supporting materials within the PCM structure.