Titania Nanopores as Photoelectrocatalysts for Coupling Hydrogen Production with Plastic Reformation

Abstract Photoelectrochemical (PEC) water splitting offers a sustainable pathway for solar‐to‐chemical energy conversion, yet its efficiency is often limited by sluggish water oxidation and the generation of low‐value oxygen. Here, the use of engineered titania nanopore (TNP) films is reported, fabricated via anodization and thermal annealing, as co‐catalyst‐free photoanodes for coupling hydrogen evolution reaction (HER) with polyethylene terephthalate (PET) reformation into high‐value formate. By tuning the crystallographic phase of TiO ₂ from amorphous to anatase and rutile, the optimized anatase‐phase electrode exhibits excellent PEC performance in a two‐electrode configuration, achieving a high steady‐state photocurrent density of [2.34 ± 0.67] mA cm ⁻² , a hydrogen evolution output of 1771 ± 30 µL cm ⁻² , a formate yield of 1.68 ± 0.05 mmol L ⁻¹ , and a Faradaic efficiency of 85 ± 9.0%. Notably, despite the absence of noble metals or complex heterostructures, the PEC performance of the TNP films is comparable to, or even surpasses, that of reported systems employing additional co‐catalysts. This study establishes a simple and scalable PEC platform for simultaneous green hydrogen production and plastic waste valorization, offering new opportunities for sustainable energy and environmental technologies.