The effect of phase structures on the near-infrared photocatalytic activity of NaYF4:Yb3+, Tm3+/ZnO nanocomposites

• α/β-­NaYF4:Yb3+, Tm3+/ZnO NCs, a near-infrared (NIR) light photocatalyst, were successfully fabricated by a high temperature decomposition reaction method.
• The photocatalytic activities of as-prepared α/β-NYT/ZnO NCs were studied upon NIR irradiation.
• The α-NYT/ZnO NCs exhibited higher photocatalytic activity than that of β-NYT/ZnO NCs for the degradation of RhB under NIR irradiation.

In this work, the effects of NaYF4:Yb3+, Tm3+ (NYT) structure on the near-infrared light (NIR) photocatalysis performance of ZnO were investigated. α-NYT/ZnO nanocomposites (NCs) and β-NYT/ZnO NCs were fabricated by a high temperature decomposition reaction method. The prepared NCs were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–vis spectroscopy, Raman spectroscopy, and photoluminescence spectra (PL). The NIR photocatalytic activities of the synthesized α- and β-NYT/ZnO NCs were studied by the degradation of Rhodamine B. The differential photocatalytic activities between of α- and β-NYT/ZnO NCs are believed to be correlated to the effects of α- and β-NYT on the oxygen vacancies and exposed crystal face of ZnO.