Sustainable Engineering and Applications of Metal–Organic Frameworks (MOFs) and Their Derivatives from Waste PET Bottles as a Potent Resource of Acid Linkers

The exponential rise of non-biodegradable plastic and its derived waste materials poses a serious threat to ecosystems worldwide, demanding urgent action. A key approach that emphasizes sustainability and environmental safety entails recycling these waste materials into value-added products that can be used to address a wide range of environmental issues such as water pollution, polyethylene terephthalate (PET), energy shortages, and greenhouse gas emissions. PET, a chemically stable polyester with numerous applications, has witnessed an enormous spike in production and consumption in recent decades. The expansion has resulted in a corresponding agglomeration of waste PET at alarming rates, exacerbating health and environmental issues. Current waste management protocols, including land-filling and burning, along with traditional recycling procedures generating low-value products, have culminated in a poor PET recycling rate of less than 30%, necessitating innovative solutions. One captivating avenue lies in the transformation of waste PET bottles into highly valuable metal–organic frameworks (MOFs). Among several value-added products generated from waste, MOFs hold immense potential in diverse applications such as battery engineering, sustainable catalysis, sensor applications, gas adsorption and separation. This chapter delineates the fabrication of MOF organic linkers sourced from recycled PET waste. Moreover, it explores the multiple utilities of engineered MOFs in resolving environmental challenges such as H2 and CO2 capture, H2 storage, catalysis, sensing, adsorptive removal of dyes and medicinal wastes from aqueous environments, and energy applications. Each application is analyzed with a discerning eye, showcasing both the challenges and advantages inherent in their implementation while also enlightening the enormous opportunities for future breakthroughs in this flourishing field of research.