From polyvinyl chloride waste to activated carbons: the role of occurring additives on porosity development and gas adsorption properties

Electrophotocatalysis for Reductive Defluorination of PTFE and PFASs

Polytetrafluoroethylene (PTFE) is among the most inert poly- and perfluoroalkyl substances (PFASs) and its degradation under mild conditions remains underdeveloped. We report a supercapacitor-assisted electrophotocatalysis, incorporating the strength of both electrochemical and photochemical energy, for the efficient defluorination of PTFE and other PFASs at low temperatures. CBZ6 worked as a photoreductant for injecting electrons into the inert carbon-fluorine bond, whereas the supercapacitor enabled the generation of the catalytically active species via an electrophotochemical process. Furthermore, the utilization of sunlight as the light source and supercapacitor as the electrical energy source makes the reaction portable and enables its outdoor applications.

Catalytic Upgrading of Plastic Wastes into High-Value Carbon Nanomaterials: Synthesis and Applications

The surge in waste plastics has placed a serious burden on the global ecosystem. Traditional recycling methods are insufficient to handle the growing volume of plastic waste, highlighting the urgent demand for innovative recycling technologies. Transforming plastics into high-value carbon nanomaterials is a simple and efficient resource recovery strategy, especially effective for handling mixed or hard-to-separate plastic waste. This method not only simplifies the sorting of discarded plastics but also offers significant advantages in recovery efficiency and processing convenience. This review systematically summarized various technologies for converting plastics into carbon nanomaterials, focusing on the catalytic mechanisms of different conversion methods. We also analyzed how various catalysts, catalytic temperatures, and metal-support interactions affect the yield and quality of carbon nanomaterials. Additionally, the potential applications of carbon nanomaterials in environmental remediation, energy storage, and catalysis are also evaluated. The ongoing challenges and future research directions in this field are critically discussed, which will ultimately facilitate more effective resource recovery from plastics and contribute to the realization of a circular economy. We believe that this review will inspire more creativity in designing such win-win reaction systems to realize a "waste treat waste" concept.

Polymer Waste Valorization into Advanced Carbon Nanomaterials for Potential Energy and Environment Applications

The rise in universal population and accompanying demands have directed toward an exponential surge in the generation of polymeric waste. The estimate predicts that world-wide plastic production will rise to ≈590 million metric tons by 2050, whereas 5000 million more tires will be routinely abandoned by 2030. Handling this waste and its detrimental consequences on the Earth's ecosystem and human health presents a significant challenge. Converting the wastes into carbon-based functional materials viz. activated carbon, graphene, and nanotubes is considered the most scientific and adaptable method. Herein, this world provides an overview of the various sources of polymeric wastes, modes of build-up, impact on the environment, and management approaches. Update on advances and novel modifications made in methodologies for converting diverse types of polymeric wastes into carbon nanomaterials over the last 5 years are given. A remarkable focus is made to comprehend the applications of polymeric waste-derived carbon nanomaterials (PWDCNMs) in the CO2 capture, removal of heavy metal ions, supercapacitor-based energy storage and water splitting with an emphasis on the correlation between PWDCNMs' properties and their performances. This review offers insights into emerging developments in the upcycling of polymeric wastes and their applications in environment and energy.

On the use of plastic precursors for preparation of activated carbons and their evaluation in CO2 capture for biogas upgrading: a review

In circular economy, useful plastic materials are kept in circulation as opposed to being landfilled, incinerated, or leaked into the natural environment. Pyrolysis is a chemical recycling technique useful for unrecyclable plastic wastes that produce gas, liquid (oil), and solid (char) products. Although the pyrolysis technique has been extensively studied and there are several installations applying it on the industrial scale, no commercial applications for the solid product have been found yet. In this scenario, the use of plastic-based char for the biogas upgrading may be a sustainable way to transform the solid product of pyrolysis into a particularly beneficial material. This paper reviews the preparation and main parameters of the processes affecting the final textural properties of the plastic-based activated carbons. Moreover, the application of those materials for the CO₂ capture in the processes of biogas upgrading is largely discussed.

Review of polymer technologies for improving the recycling and upcycling efficiency of plastic waste

Human society has become increasingly reliant on plastic because it allows for convenient and sanitary living. However, recycling rates are currently low, which means that the majority of plastic waste ends up in landfills or the ocean. Increasing recycling and upcycling rates is a critical strategy for addressing the issues caused by plastic pollution, but there are several technical limitations to overcome. This article reviews advancements in polymer technology that aim to improve the efficiency of recycling and upcycling plastic waste. In food packaging, natural polymers with excellent gas barrier properties and self-cleaning abilities have been introduced as environmentally friendly alternatives to existing materials and to reduce food-derived contamination. Upcycling and valorization approaches have emerged to transform plastic waste into high-value-added products. Recent advancements in the development of recyclable high-performance plastics include the design of super engineering thermoplastics and engineering chemical bonds of thermosets to make them recyclable and biodegradable. Further research is needed to develop more cost-effective and scalable technologies to address the plastic pollution problem through sustainable recycling and upcycling.