Enhanced photocatalytic hydrogen evolution via ball-milled PtO2/TiO2 heterojunction photocatalyst: An alternative approach for efficient energy production

• Maximum hydrogen evolution rate: 54 mmol∙h −1 ∙g −1 under UV–visible light. • Kinetic modeling predicts hydrogen production across experimental conditions. • Apparent quantum efficiency reaches 38 % in the UVA range. • Light-to-chemical energy efficiency achieves 15.6 %. A novel PtO 2 /TiO 2 heterojunction photocatalyst was synthesized via ball milling and investigated for its potential in photocatalytic hydrogen production. The effects of PtO 2 loading, catalyst concentration, and sacrificial agent concentration on the hydrogen evolution rate (HER) were systematically evaluated. The results indicate that increasing the PtO 2 concentration in the catalyst significantly enhances the hydrogen production rate, reaching a maximum value of approximately 54 mmol∙h −1 ∙g −1 at a PtO 2 concentration of 20 wt%. The effect of the sacrificial agent concentration on the hydrogen production exhibited a Langmuir-Hinshelwood behavior with constant hydrogen production rates at sacrificial agent concentrations greater than 2.5 M. The experimental results were described by a kinetic model to shed light on the reforming mechanism. Finally, the stability of the photocatalyst was confirmed through four consecutive cycle tests. This synergistic integration of experimental and modelling analyses provides a robust platform for uncovering mechanistic details of photocatalytic hydrogen generation using a photocatalyst synthesized through a facile preparation method.