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, Zn x Cd 1– x S nanoparticle (NP) photocatalysts with different concentrations of Zn 2+ ions ( x = 0.0, 0.3, 0.5, or 0.7) were successfully synthesized. The photocatalytic activities of Zn x Cd 1– x S 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 Zn x Cd 1– x S NPs. In addition, in situ X-ray photoelectron spectroscopy was performed to investigate the effect of the concentration of Zn 2+ ions on the irradiation wavelength for photocatalytic activity. Furthermore, wavelength-dependent photocatalytic degradation (PCD) activity of the Zn x Cd 1– x S NPs was investigated using biomass-derived 2,5-hydroxymethylfurfural (HMF). We observed that the selective oxidation of HMF using Zn x Cd 1– x S NPs resulted in the formation of 2,5-furandicarboxylic acid via 5-hydroxymethyl-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 Zn 2+ ions in the Zn x Cd 1– x S NPs.