Photocatalytic hydrogen evolution over mechanochemically synthesized Bi2Te3/TiO2 heterojunctions

Mechanochemically prepared Bi 2 Te 3 /TiO 2 heterojunctions were evaluated as photocatalysts for hydrogen evolution via photoreforming of alcohol and alkanolamine solutions. The morphology and optical properties of the materials, synthesized via ball milling, were characterized and hydrogen evolution was evaluated as a function of Bi 2 Te 3 loading and sacrificial agent concentration under UV and visible light irradiation. The hydrogen evolution rate increased with Bi 2 Te 3 loading and peaked at 10 wt%, (1.02 mmol h −1 g −1 ) using TEOA. The composites exhibited excellent stability over repeated use, maintaining consistent H 2 evolution across four consecutive reaction cycles. The adsorption of the sacrificial agents on the catalyst was quantified using DFT and a kinetic model was developed and fitted to mass transport-free hydrogen evolution data. TEOA consistently outperformed methanol and reached constant hydrogen evolution rates at low concentration ( ∼ 0.1 M). The model successfully reproduced the observed trends providing physically interpretable rate coefficients that link catalyst structure, surface chemistry, and performance.