Intercrossed Sheet-Like Ga-Doped ZnS Nanostructures with Superb Photocatalytic Actvitiy and Photoresponse

Abstract

Intercrossed ZnS nanostructures doped with Ga (ZnS:Ga nanowalls) have been synthesized in high yield from mixed powders in a vacuum furnace. ZnS:Ga nanowalls were grown vertically on the substrate with the size in the range of several micrometers and the thickness down to ∼15 nm and have very rough edges. Due to the high surface area and distinctive morphology of ZnS:Ga nanowalls, the photocatalytic activity and the photoresponse show superior properties compared to ZnS:Ga films. The increased conductivity of metal−semiconductor−metal (Ag−ZnS:Ga nanowalls−Ag) Schottky photodetectors under light illumination is attributed to the photogenerated electron−hole pairs, the desorption of oxygen molecules on the ZnS:Ga surface, and the lowering of the Schottky barrier height. The results indicate that ZnS:Ga nanowalls are promising candidate materials for photocatalysts and applicable as photodetectors, optical switches, and sensors in the visible light region.

Metal sulfide nanostructures: synthesis, properties and applications in energy conversion and storage

“…59,60 Doping of metal ions into wide band gap metal sulfide semiconductor nanomaterials has been used to prepare photocatalysts. 11 Fig. 6 shows excellent photocatalytic activity of ZnS: Ga nanowalls.…”

“…2, various zinc sulfide nanostructures, such as ZnS nanowire arrays, ZnO-ZnS heterojunction nanowire arrays, ZnS:Ga nanowalls and Co x Zn 1Àx S nanowires, have been synthesized by thermal evaporation in a vacuum tube furnace under controlled conditions. 11,34,35 One-dimensional single-crystalline DMS Co x Zn 1Àx S nanowires with different doping levels have been synthesized by the thermal evaporation method using different amounts of CoCl 2 $6H 2 O powders as dopant source via the vapor-liquid-solid (VLS) growth mechanism. 34 Axial heterostructured ZnO-ZnS NW arrays have been synthesized based on a one-step thermal evaporation with ZnS powders.…”

“…19,20 On the other hand, ZnS can also serve as an important semiconductor photocatalyst to remove toxic or organic water pollutants owing to the highly negative reduction potentials of excited electrons and the rapid generation of electron-hole pairs. 11 Copper sulfide (Cu 2 S) is an important p-type semiconductor and has great potential applications as cathode materials for lithiumion batteries, solar radiation absorbers and nonlinear optical materials. 7 It is appealing as an extremely thin absorber layer in solar cells due to its nearly ideal bandgap of 1.2 eV and low cost.…”

“…J is the Schottky barrier height at the metal/ ZnS interface. (b) The temperature dependent I-V characteristics of ZnS:Ga nanowall MSM photodetectors measured at temperatures between 300 and 448 K. The inset is the plot of ln (I/T 2 ) versus 1/T at V ¼ +1 and À1 V and the effective Schottky barrier heights are extracted to be 0.16 and 0.39 eV, respectively 11. …”

One-dimensional II–VI nanostructures: Synthesis, properties and optoelectronic applications

“…On the other hand, Cheng and Wang reported Eu 2+ -doped wurtzite ZnS NWs with long-lasting phosphorescence [50]. Lu et al synthesized Ga-doped ZnS nanowalls with better photo-catalytic and photoresponse properties than the film counterpart [51]. In spite of these progresses, doping in ZnS nanostructures with high controllability and reproducibility remains a challenge due to the complexity of the growth process.…”