Revealing Photocatalytic Performance of ZnXCd1-XS Nanoparticles Depending on the Irradiation Wavelength

Photocatalysts are useful for various applications, including the conservation and storage of energy, wastewater treatment, air purification, semiconductors, and production of high-value-added products. Herein, ZnxCd1-xS nanoparticle (NP) photocatalysts with different concentrations of Zn2+ ions (x = 0.0, 0.3, 0.5, or 0.7) were successfully synthesized. The photocatalytic activities of ZnxCd1-xS NPs varied with the irradiation wavelength. X-ray diffraction, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, and ultraviolet-visible spectroscopy were used to characterize the surface morphology and electronic properties of the ZnxCd1-xS NPs. In addition, in situ X-ray photoelectron spectroscopy was performed to investigate the effect of the concentration of Zn2+ ions on the irradiation wavelength for photocatalytic activity. Furthermore, wavelength dependent photocatalytic degradation (PCD) activity of the ZnxCd1-xS NPs was investigated using biomass-derived 2,5-hydroxymethylfurfural (HMF). We observed that the selective oxidation of HMF using ZnxCd1-xS NPs resulted in the formation of 2,5-furandicarboxylic acid via 5hydroxymethyl-2-furancarboxylic acid or 2,5-diformylfuran. The selective oxidation of HMF was dependent on the irradiation wavelength for PCD. Moreover, the irradiation wavelength for the PCD depended on the concentration of Zn2+ ions in the ZnxCd1-xS NPs.