Globally, over eight billion tons of plastic waste have accumulated, with less than 10% being recycled. This not only poses an environmental issue, with much ending up in landfills and oceans but also represents an underutilized opportunity for valorization into fuels and chemicals. Several methods, such as chemical, biological, and pyrolytic, have been investigated for plastic valorization.Photocatalytic plastic upcyclingis particularly promising for fuel production, as it is solar-driven and energy-neutral. This project targetsusing plastic waste, especially polyethylene terephthalate (PET), for hydrogen production, given the favourable thermodynamics/kinetics of oxidizing organic substrates like ethylene glycol (a PET monomer) compared to water-splitting. Yet, plastic-to-hydrogen photoconversion remains nascent (Technology Readiness Level: 1-3), with several challenges and research gaps: 1. Harsh chemical pre-treatments to depolymerize plastics. 2. Poor hydrogen yields due to inefficient/incomplete depolymerization and ineffective charge transport in photocatalysts. 3. Lack of integration between chemical, biocatalytic, and photocatalytic approaches. This project aims to derive clean hydrogen from PET plastic waste using a semi-biological approach. We propose designing and evaluating hybrids of promiscuouspolyester hydrolases(mainly,PHL7,PET44, andLCC) for PET depolymerization, coupled withS-scheme heterojunction photocatalyststo drive ethylene glycol oxidation and hydrogen evolution reactions. Although S-schemes are known to boost hydrogen evolution in solar water splitting through enhanced charge separation/transfer, their potential in solar plastic-to-hydrogen conversion remains underexplored. For photocatalytic hydrogen generation from PET, its effective depolymerization is crucial. This is typically done by alkaline hydrolysis. The biocatalytic depolymerization proposed here is environmentally benign with milder reaction conditions, compared to alkaline hydrolysis. However, there are challenges, namely (1) non-reusability of enzymes (especially considering the cost of isolating/purifying enzymes), (2) limited stability. Herein, we propose a biohybrid design wherehydrolase enzymes are immobilized in Metal-Organic Frameworks (MOF). As opposed to enzyme-hybrids with 3D-MOFs (where plastic-enzyme interactions are severely restricted by the MOF pore size), employing2D-MOFs can sustain enzyme activity, while promoting enzyme reusability and thermostability. While the enzyme-hybrid is vital for PET depolymerisation, the hydrogen yield hinges on the photocatalytic processes. We will therefore extensively study the photocatalyst design to evaluate and enhance the charge separation and transfer. Several heterojunction designs will be investigated, namelySingle S-Scheme(with direct or indirect recombination) anddouble S-Scheme designs(with dual-oxidation or dual-reduction sites). Finally, for practical demonstration, we will explore two reactor designs: a suspension photocatalytic reactor (including sequential and concurrent variants) and a photoelectrochemical reactor for enhanced H2yield.