Enhanced visible–NIR-driven photocatalytic activities over NaYF4:Yb3+, Er3+/Ag2CrO4 composite

Wide spectral responsive photocatalysts are of great importance for making full use of solar energy and broad application in highly efficient photocatalytic wastewater treatment, production of H2O2, etc. Thereinto, it is significative to open an appropriate way to extend the absorption to the NIR region, in which it accounts for ~ 49% in the solar spectrum. In this work, we synthesized successfully the new-style NaYF4:Yb3+, Er3+/Ag2CrO4 photocatalyst via the hydrothermal and followed precipitation method, and it exhibited the more excellent photocatalytic performances than Ag2CrO4 for the photocatalytic H2O2 production and disposals of pollutants, such as methyl orange (MO), methylene blue (MB), rhodamine B (RhB) and tetracycline (TCs). The morphological, structural and optical behavior were investigated by XRD, SEM, N2 adsorption/desorption, TEM, XPS, UV–Vis DRS, UC luminescence and photoelectrochemical experiments. It revealed that NaYF4:Yb3+, Er3+/Ag2CrO4 photocatalyst presented stronger absorptive capacity in the visible–NIR region by the benign fluorescence resonance energy transfer (NaYF4:Yb3+, Er3+ can convert near-infrared light to visible light via upconversion process), and showed more efficient charge transfer and separation than that of pure Ag2CrO4. The primary reactive species of ·O2− and h+ by the trapping experiments played a considerable important role in the photocatalytic process. A promising potent system was suggested for the highly efficient utilization of sunlight in the enhancement of photocatalytic activities.