NaYF4:Yb,Er/MnIn2S4/g-C3N4 with visible near infrared light response for efficient photocatalytic degradation

Abstract

In the treatment of wastewater, the use of semiconductor photocatalysis is known to be environmentally friendly. Composites of MnIn2S4 for visible and near-infrared photocatalysis are less well studied. In this article, we have fabricated a ternary composite material, NaYF4:Yb,Er/MnIn2S4/g-C3N4, through a simple synthesis method for visible and near infrared photocatalysis. MnIn2S4 and g-C3N4 form the heterogeneous junction. The spectral response can be extended to the NIR range by integrating NaYF4:Yb,Er nanocrystals (NCs) with MnIn2S4/g-C3N4. Comparing MnIn2S4/g-C3N4 to single-component samples, photocatalytic performances under visible light irradiation showed that it had higher photocatalytic activities. When NaYF4:Yb,Er NCs are coated onto the petal-like spherical structure of MnIn2S4/g-C3N4 and integrated with it, the heterostructure and upconversion effect enhance the photocatalytic activity of the composites under Vis and NIR light. The photocatalytic mechanism of the nanocomposites has been postulated and its detailed characterization has been done. Based on the results of UHPLC-MS, the degradation process and rational pathways for degradation of CIP were proposed. The environmental toxicity of CIP degradation products was evaluated using ECOSAR software, the results showed that the toxicity of the reaction solution was diminished after 60 min of photodegradation. The current study not only avoids the generation of toxic by-products in the photocatalytic degradation process but also MnIn2S4-based composites may open up new possibilities for the design and production of composite photocatalysts that may effectively use Vis/NIR light for environmental remediation.