Plastic waste should not be viewed as a uniform refuse stream, but as a heterogeneous carbon reservoir whose recycling pathway is dictated by polymer composition, contamination level and degradation history. Here, we outline a graded recycling framework that prioritizes carbon retention rather than technology-driven conversion. Clean and separable plastic streams should first undergo physical recycling to preserve polymer backbones and avoid unnecessary bond cleavage. Mixed, aged or contaminated fractions are better suited to selective chemical routes, including solvolysis, hydrogenolysis, catalytic depolymerization, electrified pyrolysis and gasification, which can reconstruct carbon into monomers, hydrocarbons, syngas or platform chemicals. Biological recycling is most effective for oxygenated intermediates generated through pretreatment. Integrating sorting, safety control and life-cycle assessment, this physical–chemical–biological hierarchy matches each plastic carbon stream with its most valuable and sustainable conversion pathway.

This review summarizes recent progress in microwave-driven catalytic conversion of waste plastics. It covers the synergy between microwave dielectric heating and catalysis, depolymerization pathways of various plastics, catalyst design and structure-activity relationships, and effects of reaction parameters on product distribution. Key challenges are discussed, including unclear mechanisms, catalyst deactivation, and scale-up difficulties. Future directions are proposed, such as multi-scale mechanistic studies, development of stable catalysts, and continuous-flow reactor design.

Halogenated organic compounds (HOCs) are widely used in industrial and consumer products, but some are highly persistent and difficult to analyze and manage. In a new study, researchers have developed an innovative approach for carbon isotope ratio analysis of these compounds, which has been previously difficult. This approach will help track the source and environmental pathways of such pollutants, contributing to the development of effective management strategies.

Physicists at the University of Graz (Austria), in collaboration with colleagues from Marburg University and Forschungszentrum Jülich (Germany), have achieved a scientific breakthrough. For the first time, the generation of electrical energy from light has been filmed and described theoretically. This work is of far-reaching significance, not least for optimising sustainable energy production from photovoltaics. This is because it provides fundamental building blocks for understanding the physical processes that take place, for example, in organic solar cells. The paper was published in the journal Physical Review X, one of the world’s most prestigious physics journals.

Oxyfluoride crystals are promising electrolyte candidates for safer solid-state lithium-ion (Li-ion) batteries. Two years ago, a new oxyfluoride was reported to have an unusually large lithium-ion conductivity. Now, researchers from Nagoya University in Japan have uncovered why it works so well and attained a record-high conductivity at room temperature among oxide-related solid electrolytes.