Size-Controlled Electron Transfer and Photocatalytic Activity of ZnO–Au Nanoparticle Composites

Abstract

This Letter describes size-controlled photocatalytic activity of ZnO nanoparticles coated with glutathione-protected gold nanoparticles with diameters of 1.1, 1.6, and 2.8 nm. The photocatalytic activity of the ZnO–Au composites was found to increase with increasing gold size for both oxidative and reductive catalytic reactions. Photoluminescence decay dynamics of the composites showed that the electron-transfer rate from the photoexcited ZnO to gold nanoparticle also increased as the gold size increased. These results demonstrate that the photogenerated electron transfer and the resulting catalytic activity of the composites can be controlled by the size of the mediating gold capacitors.

Au/PtO nanoparticle-modified g-C 3 N 4 for plasmon-enhanced photocatalytic hydrogen evolution under visible light

“…The results show that the fast component (s 1 and A 1 , corresponding to the decay time and relative magnitude, respectively) is dominant, which is due to the decay from free exciton states. And the minority-slow component (s 2 and A 2 ) originates from the bound exciton states [46,47]. It can be seen that the fluorescence lifetimes are much shortened after the introduction of Au and PtO species, indicating a nonradiative pathway due to the electron transfer process from g-C 3 N 4 to the cocatalysts.…”

“…The fluorescence lifetime s is defined as the time when the fluorescence intensity (I t ) decays to 1/e of I 0 . Here the emission decay data are fitted by a biexponential model [45,46]. The results show that the fast component (s 1 and A 1 , corresponding to the decay time and relative magnitude, respectively) is dominant, which is due to the decay from free exciton states.…”

Hierarchical nanostructures of Au@ZnO: antibacterial and antibiofilm agent

“…In this regard, the occurrence of metal nanoparticles on the surface of semiconductor nanostructures is expected to change the optical and electronic properties of noble metal/metal oxide hybrid nanostructures by increasing the efficiency of charge carrier separation and extending light absorption and facilitating creation of electron/hole pairs induced by the surface plasmon resonance (SPR) effect (especially for Au and Ag) (Lee et al 2011;Mubeen et al 2013).…”

Simultaneous Waste Water Purification via Photocatalysis and Seed Germination

“…Materials thoroughly studied for photocatalytic use are TiO 2 and ZnO [9][10][11][12]. Several other materials like Bi 2 MoO 6 , Bi 2 WO 6 , BiVO 4 , CdS, WO 3 , KTiNbO 5 etc.…”