Functionalized Silicate Sol-Gel-Supported TiO2-Au Core-Shell Nanomaterials and Their Photoelectrocatalytic Activity

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.