Photo-driven valorization of polylactic acid into hydrogen fuel and pyruvate using a biotic-abiotic configuration

Plastics are among the most widely used materials in modern society. Polylactic acid (PLA) is a bioplastic polymer employed in numerous applications. Its demand is expected to markedly increase in the coming years, highlighting the need for sustainable degradation methods. Mechanical and chemical recycling methods can degrade PLA; however, these are often energy-intensive and form polluted side streams. Biocatalysis offers a greener approach to depolymerizing PLA into lactic acid. Proteinase-K facilitates the hydrolysis of the ester bonds in the PLA chains. Herein, we present a holistic approach for the photoconversion of PLA into H 2 fuel and pyruvate under mild conditions using CdS/NiS NPs as photocatalysts. The nickel sulfide co-catalyst significantly enhanced the hydrogen production by 100-fold, while pyruvate was the sole photooxidized product. Overall, the designed system presents a clean and promising strategy for sustainable plastic valorization under mild and environmentally friendly conditions. • A holistic approach for the conversion of PLA into H 2 fuel was developed. • Proteinase-K facilitates the hydrolysis of PLA to lactic acid. • Lactic acid is oxidized by visible light irradiated CdS/NiS NPs, yielding pyruvate. • The photogenerated electrons facilitate proton reduction to generate H 2 Fuel. • NiS photodeposition on the CdS NPs increases hydrogen production by 100-fold.