High-quality Cu2ZnSnS4 and Cu2ZnSnSe4 nanocrystals hybrid with ZnO and NaYF4: Yb, Tm as efficient photocatalytic sensitizers

A chloroform-assistant Se dissolution in oleylamine without trioctylphosphine and alkylthiol as the green precursor was used for facile and robust synthesis of quaternary selenide nanocrystals. The S 2− modified hydrophilic Cu 2 ZnSnS 4 and Cu 2 ZnSnSe 4 nanocrystals were first prepared by a one-pot thermal decomposition route, followed by a bi-phase hydrophilic treatment process. As a proof of concept, the as-obtained hydrophilic nanocrystals were hybridized with ZnO microspheres as photosensitizers to achieve visible light-driven photocatalytic application; on the other hand, hybridized with NaYF 4 : Yb, Tm microplates to achieve near-infrared light-driven photocatalytic application. These photosensitized hybrids as photocatalysts expanded the light absorption from ultraviolet to visible even near-infrared region, which showed excellent photocatalytic Rhodamine B degradation under visible and near-infrared irradiation compared to pure ZnO and NaYF 4 : Yb, Tm, respectively. Therefore, these hydrophilic Cu 2 ZnSnS 4 and Cu 2 ZnSnSe 4 nanocrystals are proved as efficient photocatalytic sensitizers due to the efficient utilization of the visible light and emissions upconverted from near-infrared light.