Comprehensive Insights into Photoreforming of Waste Plastics for Hydrogen Production

The global plastic crisis, characterized by over 400 million metric tons of annual production and low recycling rates, has evolved into a pressing environmental and energy challenge. Photocatalytic plastic photoreforming presents a dual-benefit strategy that transforms non-recyclable waste plastics into hydrogen fuel and valuable organic byproducts using solar energy under mild conditions. This review critically examines recent advances in photocatalyst design, including semiconductors, metal-organic frameworks-derived composites, and co-catalyst systems, alongside emerging insights into polymer degradation pathways and reactor configurations. Key operational parameters such as pH, light intensity, flow dynamics, and substrate properties are analyzed for their influence on hydrogen yields and byproduct selectivity. Life-cycle assessment and techno-economic analysis reveal that while current photoreforming systems face hurdles related to quantum efficiency, scalability, and cost competitiveness, innovations in material synthesis, light management, and integrated system design offer promising solutions. The potential to upcycle complex plastic waste into hydrogen aligns photoreforming with circular economy principles, particularly if combined with policy incentives and advanced separation strategies to mitigate environmental risks. With the convergence of environmental remediation and renewable energy production, plastic photoreforming emerges as a viable contributor to sustainable hydrogen economies.