Microwave‐Assisted Synthesis of Ag‐Decorated TiO ₂ Nanotubes for Photocatalytic Hydrogen Evolution

Abstract Microwave (MW)‐assisted aqueous synthesis of nanostructures offers an environmentally friendly alternative that aligns with green chemistry principles. In this study, we report the synthesis of silver nanoparticles (AgNPs) using a standard commercial MW oven and an aqueous extract of fresh cassava root, which served simultaneously as solvent and reducing/stabilizing agent. TiO 2 nanotubes (NTs), synthesized via a MW digestion system, were impregnated with the as‐prepared AgNPs, and their photocatalytic activity was evaluated for hydrogen generation. The physicochemical properties of the synthesized AgNPs were characterized using various techniques, including FTIR, HAADF‐STEM, UV–visible (vis)DRS, RBS, and XPS. The average diameter of the AgNPs impregnated on TiO 2 NTs, as measured by HAADF‐STEM, was (1.7 ± 0.2) nm. Increasing the AgNO 3 concentration led to the formation of larger particles with a broader size distribution. Incorporation of very small AgNPs into TiO 2 NTs resulted in a significant enhancement of the hydrogen evolution rate during methanol photoreforming at room temperature, increasing from 2.45 µmol g −1 h −1 for pristine TiO 2 NTs to 4.1 µmol g −1 h −1 . Reports on the use of green AgNPs prepared by MW‐assisted irradiation in hydrogen photogeneration experiments remain scarce in the literature, suggesting promising opportunities for advancing sustainable energy applications.