Upgrading Polyolefin Plastics Into Ethanol Using an Integrated Hydrothermal-Photoelectrocatalytic Strategy

Polyolefin plastics, such as polyethylene (PE), possess chemically inert and nonpolar C–C backbones, making them difficult to recycle and causing persistent environmental pollution. The lack of green and highly selective upcycling methods has led to severe environmental concerns and resource waste. Photoelectrocatalysis utilizes high-energy photogenerated charge carriers to directionally upgrade plastic-derived small molecules into value-added chemicals. However, current photoelectrocatalytic technologies still face challenges in processing structurally inert bulk polymer plastics. In this study, we report a hydrothermal-photoelectrocatalytic tandem strategy to realize the upcycling of PE and other polyolefin plastics. The acetic acid product obtained from hydrothermal treatment are further converted into ethanol over an Au nanoparticle‑decorated GaN/Si (Au/GaN/Si) photocathode, achieving an optimal performance of a Faradaic efficiency of 57.6%. This tandem strategy also demonstrates excellent generality in the conversion of polypropylene (PP) and polyvinyl chloride (PVC), providing a green route for the upcycling of polyolefin plastics. Graphical Hydrothermal-photoelectrocatalytic tandem upcycling enables the conversion of chemically inert polyolefin plastics into value-added ethanol. The Au/GaN/Si photocathode achieves a Faradaic efficiency of 57.6% for ethanol production, while demonstrating broad applicability to PE, PP, and PVC plastics.