The growing demand for plastic products in our daily lives generates massive amounts of wastes each year. Further enhanced by the COVID-19 pandemic, the use of single-use medical plastic materials (such as masks and gloves) for health protection has resulted in a significant increase in (micro)plastic post-consumer wastes. The current disposal routes are mainly thermal utilization (incineration) and landfill, which is environmentally unfriendly. More efficient and sustainable recycling methods are desperately needed to turn the waste plastics into value-added chemicals or materials. Chemical recycling approaches like pyrolysis provide a potential cyclic economy route to manage the plastic wastes. The plastic wastes can be directly transformed into chemical products including H₂-rich gases, hydrocarbon fuels, and carbon nanomaterials.

In this work, waste medical masks collected from daily life usage were pyrolyzed and catalytically decomposed with perovskite-type La_0.6Ca_0.4Co_1–xFe_xO_3−δ pre-catalysts for co-production of H₂ and carbon composite materials. The influences of catalysis reaction temperature and Co/Fe ratio in the investigated pre-catalysts on the yields and selectivity of the gaseous products and carbon deposition were systematically studied. The physicochemical characteristics of the produced carbon nanomaterials were comprehensively characterized by the state-of-the-art techniques. La_0.6Ca_0.4Co_0.2Fe_0.8O_3–δ possessed the highest hydrogen and carbon nanomaterials yields at 850 °C among all the investigated pre-catalysts. Especially, this pre-catalyst showed an excellent performance during 10 cycles of successive deconstruction of plastic wastes with the highest hydrogen yield at the 7^th cycle. More importantly, the generated carbon nanotubes generated high graphitic characteristics and few disorder. The presented results demonstrated that the developed perovskite pre-catalyst is a promising candidate for co-producing hydrogen and carbon nanotube composites for energy storage applications from medical waste plastics.