Mechanothermal synthesis of Ag/TiO2 for photocatalytic methyl orange degradation and hydrogen production

Photocatalysis offers a promising route to address the challenges of future energy production and anthropogenic environmental pollution. Here we demonstrated the synthesis of a high activity Ag/TiO2 photocatalyst through a two-step, sol-gel and mechanothermal decomposition method employing a silver acetate precursor. Bulk and surface characterization revealed the formation of dispersed metallic silver nanoparticles (∼9 nm diameter) decorating anatase crystallites (∼14 nm) which stabilized a significant concentration of Ti3+ surface species. Synergy between silver and titania enhanced the photophysical properties, narrowing the band gap and suppressing charge-carrier recombination. Ag/TiO2 exhibited good visible light activity and excellent stability over 3 cycles for the aqueous phase photocatalytic degradation of methyl orange dye (38 μmol/h/gcat), and excellent hydrogen production from water splitting (910 μmol/h/gcat).