Photoreforming of Waste Polymers for Sustainable Hydrogen Fuel and Chemicals Feedstock: Waste to Energy

Energy from renewable resources is central to environmental sustainability. Among the renewables, sunlight-driven fuel synthesis is a sustainable and economical approach to produce vectors such as hydrogen through water splitting. The photocatalytic water splitting is limited by the water oxidation half-reaction, which is kinetically and energetically demanding and entails designer photocatalysts. Such challenges can be addressed by employing alternative oxidation half-reactions. Photoreforming can drive the breakdown of waste plastics and biomass into valuable organic products for the production of H2. We provide an overview of photoreforming and its underlying mechanisms that convert waste polymers into H2 fuels and fine chemicals. This is of paramount importance from two complementary perspectives: (i) green energy harvesting and (ii) environmental sustainability by decomposing waste polymers into valuables. Competitive results for the generation of H2 fuel without environmental hazards through photoreforming are being generated. The photoreforming process, mechanisms, and critical assessment of the field are scarce. We address such points by focusing on (i) the concept of photoreforming and up-to-date knowledge with key milestones achieved, (ii) uncovering the concepts and challenges in photoreforming, and (iii) the design of photocatalysts with underlying mechanisms and pathways through the use of different polymer wastes as substrates.

Automated summary

Renewable energy is crucial for environmental sustainability, and sunlight-driven fuel synthesis through water splitting is a sustainable and economical method. However, the water oxidation half-reaction in photocatalytic water splitting is challenging and requires designer photocatalysts. Photoreforming can address these challenges and convert waste plastics and biomass into valuable organic products for H2 production. This article provides an overview of photoreforming, including its mechanisms and the use of different polymer wastes as substrates for photocatalysts.