Efficient photoreforming of plastic waste using a high-entropy oxide catalyst

[Display omitted] •A high-entropy oxide (HEO) is used for photoreforming of polyethylene terephthalate (PET).•Hydrogen and, glycolic acid, formic acid, and acetic acid are produced by photoreforming.•The HEO shows higher catalytic activity than that of P25 TiO2 for photoreforming.•The high activity of HEO is discussed based on active sites and charge carrier lifetime. Simultaneous catalytic hydrogen (H2) production and plastic waste degradation under light, known as photoreforming, is a novel approach to green fuel production and efficient waste management. Here, we use a high-entropy oxide (HEO), a new family of catalysts with five or more principal cations in their structure, for plastic degradation and simultaneous H2 production. The HEO shows higher activity than that of P25 TiO2, a benchmark photocatalyst, for the degradation of polyethylene terephthalate (PET) plastics in water. Several valuable products are produced by photoreforming of PET bottles and microplastics including H2, terephthalate, ethylene glycol and formic acid. The high activity is attributed to the diverse existence of several cations in the HEO lattice, lattice defects, and appropriate charge carrier lifetime. These findings suggest that HEOs possess high potential as new catalysts for concurrent plastic waste conversion and clean H2 production.