SnO2/ZnS nanocomposites of SnO2 quantum dots (QDs)-deposited ZnS nanobelts having highly enhanced photocatalytic activity and photostability have been fabricated via a facile two-step hydrazine-assisted hydrothermal process without involving any surface treatments. The photocatalytic activity of SnO2/ZnS nanocomposites with a Sn-to-Zn molar ratio (RSn/Zn) of 0.1 is 3 times higher than that of pristine ZnS nanobelts and 17 times higher than that of commercial ZnS. The incorporation of SnO2 QDs increases the photocatalytic efficiency of ZnS nanobelts due to the following reasons: photogenerated charge carriers are readily separated owing to type II band configuration and direct contact at interfaces without having any linker molecules; active surface sites are increased to adsorb more dye molecules; the light absorption range is extended to the visible region, generating more charge carriers on the surfaces of heterojunction structures. The decay time, as well as the intensity, of the band-edge emission of SnO2/ZnS nanocomposites at 325 nm decreases progressively and rapidly with the increase of RSn/Zn, indicating that fast electron transfer takes place from photoexcited ZnS nanobelts to SnO2 QDs. Thus, the higher photocatalytic degradation efficiencies of SnO2/ZnS nanocomposites are considered to result mainly from the increased separation rates of photogenerated charges. The photostability of SnO2/ZnS nanocomposites is also improved due to the protection and charge-separation effects of decorating SnO2 QDs.

Efficient photocatalytic activity of SnO2-deposited ZnS nanobelts

253rd National Meeting (2017)

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