Functionalized silicate sol-gel-supported TiO₂-Au core-shell nanomaterials and their photoelectrocatalytic activity

Abstract

The N-[3-(trimethoxysilyl)propyl]ethylenediamine (EDAS) derived silicate matrix supported core-shell TiO₂-Au nanoparticles (EDAS/(TiO₂-Au)_nps) were prepared by NaBH₄ reduction of HAuCl₄ precursor on preformed TiO₂ nanoparticles in the presence of EDAS monomer. The core-shell (TiO₂-Au)_nps nanoparticles were stabilized by the amine functional group of the EDAS silicate sol-gel network. The potential application of this EDAS/(TiO₂-Au)_nps modified electrode toward the photoelectrochemical oxidation of methanol was explored. The EDAS/(TiO₂-Au)_nps modified electrode showed a 12-fold enhancement in the catalytic activity toward photoelectrooxidation of methanol when compared to TiO₂ dispersed in EDAS silicate sol-gel matrix. This improved photoelectrochemical performance is explained on the basis of beneficial promotion of interfacial charge transfer processes of the EDAS/(TiO₂-Au)_nps nanocomposite. A methanol oxidation peak current density of 12.3 mA cm^-2 was achieved at an optimum loading of Au_nps on TiO₂ particles. This novel amine functionalized EDAS silicate sol-gel stabilized core-shell (TiO₂-Au)_nps nanomaterial could be an excellent candidate for the photocatalytic and photoelectrochemical applications.