Embedding Pt/TiO ₂ in a Flexible Nafion Film for Enhanced Photocatalytic Hydrogen Evolution in Seawater

The photocatalytic hydrogen evolution reaction (HER) in seawater has emerged as one of the most promising technologies for the production of clean energy, yet the photocatalysts still suffer from severe salt-induced corrosion and limited mass transfer, limiting their practical applications. In addition, compared with conventional suspension-based photocatalytic systems, membrane/film-based photocatalytic systems could help to disperse catalytic nanoparticles well, realizing high photocatalytic efficiency and stability. However, the mass transportation of water molecules may be inhibited in many membrane- or film-based photocatalytic systems. Herein, we embed and immobilize Pt/TiO 2 particles in a perfluorosulfonic acid resin (Nafion) film coated on glass fiber paper for enhanced activity and stability of the photocatalytic HER in simulated seawater. The flexible Nafion film embedded with Pt/TiO 2, referred to as Nafion-Pt/TiO 2, demonstrated outstanding photocatalytic hydrogen evolution in simulated seawater. A remarkable hydrogen production rate of 7.689 mmol·g –1 ·h –1 was realized, representing a 5.37-fold enhancement compared with that of bare Pt/TiO 2 . This enhancement can be attributed to the Nafion-induced improvements in charge separation and a localized photothermal effect enabled by thermal confinement. Furthermore, the Nafion-Pt/TiO 2 system showed a superior stability, and 99.3% of its initial catalytic activity was retained after five consecutive photocatalytic cycles. This study provides valuable insights into enhancing both the activity and the stability of photocatalytic hydrogen production in seawater.