Abstract
Silver nanoparticles successfully incorporated in titanate nanosheets and synthesized hydrothermally via employing cetyltrimethylammonium bromide (CTAB) and triblock copolymer (pluronic F127) assisted templates were thoroughly characterized using transmission electron microscopy-selected area electron diffraction (TEM-SAED), X-ray diffraction, diffuse reflectance UV/visible absorption spectroscopy, N-2 sorptiometry, FTIR and Raman spectroscopy. The dispersed Ag nanoparticles of uniform size (2-3 nm) were found to contact intimately with titanate(F127) nanosheets to show superior crystallinity, wider layer distances and higher surface area and pore volume (S-BET = 51.1 m(2) g(-1), V-P = 0.081 cm(3)g(-1)) than Ag/titanate(CTAB) (7.2 m(2) g(-1), 0.02 cm(3) g(-1)). This constructed Ag/titanate(F127) exhibits markedly improved electrocatalytic (1.4-fold) and photoelectrocatalytic (4.0-fold) activities and stabilities towards methanol oxidation than that of Ag/titanate(CTAB); as determined using cyclic voltammetry, linear sweep voltammetry and chronoamperometry. The enhanced activity of Ag/titanate(F127) was also attributed to electron transfer across the interface potential of the composite Ag-titanate(F127) as well as the delay of charge recombination that has been substantiated not only via exposed Ag but also through the non-decomposed carbon template. This enhanced electron transfer and electronic conductivity was established by impedance spectroscopy, and exhibits the maximum obtained photocurrent density (2.0 mA cm(-2)) under visible light illumination (lambda > 420 nm, 88 W). The results revealed that the template F127 had a significant effect not only on enhancing the titanate crystallinity and exhibiting a surface plasmon resonance band; unlike Ag/titanate(CTAB), but also in acquiring a high pore volume value and widened layers, which all work towards improving the Ag-titanate(F127) durability for methanol oxidation.