Plasmon-Enhanced Photoluminescence and Photocatalytic Activities of Visible-Light-Responsive ZnS-AgInS₂ Solid Solution Nanoparticles

Abstract

Semiconductor-metal nanocomposite materials composed of ZnS-AgInS2 solid solution (ZAIS) nanoparticles and SiO2-coated Au particles were prepared, the particle distance between ZAIS and Au being precisely adjusted in nanometer scale by changing the thickness of the SiO2 coating layer on Au core particles. The SiO2 layer also acted as an insulator layer to prevent direct electron transfer from photoexcited ZAIS to Au particles. The photoluminescent (PL) and photocatalytic properties of ZAIS particles were modulated by the locally intensified electric field produced by photoexcitation of the localized surface plasmon resonance (LSPR) peak of Au particles. The PL intensity was enhanced with an increase in the distance between ZAIS and Au particles (d ZAIS‑Au), up to about 21 nm, due to the enhancement of photoexcitation of ZAIS particles by the LSPR-induced electric field, but a further increase in d ZAIS‑Au inversely decreased the PL intensity. The photocatalytic H2 evolution rate with ZAIS particles immobilized at the appropriate distance from Au core particles was tunable by controlling the chemical composition of ZAIS. The plasmonic enhancement of photocatalytic activity was increased with an increase in the overlapping between the absorption properties of ZAIS and the LSPR peak of Au, the maximum enhancement factor obtained being about 2 for particles of AgInS2.

Plasmon enhanced fluorescence studies from aligned gold nanorod arrays modified with SiO2 spacer layers

“…Takahashi et al also observed the fluorescence intensity being predominantly quenched at low separations of dye and metal nanostructure. For 15 nm Au NPs they observed maximum SEF at a SiO2 thickness of d=21nm, and by using lifetime measurements it was confirmed that the enhancement was due to coupling to the electromagnetic field created by the excitation of the LSPR [31]. Ge et al used 30 nm Au NPs and observed maximum SEF at d=40nm.…”

Electronic structure and absolute band edge position of tetragonal AgInS2 photocatalyst: A hybrid density functional study

“…For example, Tadjarodi et al have discovered that energy conversion efficiency of AgInS 2 nanoparticles is 1.58% when fill factor is 30%, which revealed the capability of AgInS 2 nanoparticles to be used in solar cell devices [16]; Luo et al have synthesized water-soluble AgInS 2 (AIS) nanocrystals (NCs) and ZnS-AgInS 2 (ZAIS) NCs, and found that AIS and ZAIS NCs showed promising photocatalytic activities in the degradation of rhodamine B [17]. Takahashi et al have investigated the photocatalytic activity of ZnS-AgInS 2 solid solution nanoparticles for H 2 evolution [18].…”

Enhanced Photocatalytic Hydrogen‐Production Performance of Graphene–ZnxCd1−xS Composites by Using an Organic S Source

“…[28][29][30] It was also reported that the photocatalytic activity and photostability of graphene-based solid-solution sulfide composites are usually much higher than those of graphene-based monometal sulfide composites. [31,32] For example, Zhang et al prepared a graphene-Zn x Cd 1Àx S nanocomposite by a coprecipitation-hydrothermal method with Na 2 S as the inorganic S source, and the obtained graphene-Zn 0.8 Cd 0.2 S product exhibited significantly improved photocatalytic H 2 -production activity compared to pristine Zn 0.8 Cd 0.2 S, and even better activity than optimized Pt-Zn 0.8 Cd 0.2 S under the same reaction conditions. [32] However, the effects of different S sources on the formation of high-quality composites between graphene and Zn x Cd 1Àx S solid solutions remains unexplored.…”