Revealing Photocatalytic Performance of Zn_xCd_1–xS Nanoparticles Depending on the Irradiation Wavelength

Abstract

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 Cd1–x S 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 Zn x Cd1–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 Cd1–x S 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 Zn x Cd1–x S NPs was investigated using biomass-derived 2,5-hydroxymethylfurfural (HMF). We observed that the selective oxidation of HMF using Zn x Cd1–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 Zn2+ ions in the Zn x Cd1–x S NPs.

Sunlight-driven photocatalytic conversion of furfural and its derivatives

“…Pham et al synthesized Zn x Cd 1−- x S nanoparticle photocatalysts with different concentrations of Zn 2+ ions ( x = 0.0, 0.3, 0.5 or 0.7). 24 The approach was found to be effective for controlling the band gap and promoting e − –h + separation, thereby improving the photocatalytic efficiency. In addition, the previous ZnIn 2 S 4 -TU catalyst with more Zn vacancies also enabled FDCA formation by extending the reaction time.…”

“…As a result, the focus in the field has gradually shifted to developing a range of visible-light-responsive photocatalysts with a suitable band location, in order to address the above issues. [23][24][25][26][27] In addition, photogenic radical intermediates allow for novel and meaningful reaction paths (Fig. 1 and 2) that are unlikely to be achieved in conventional heterogeneous catalysis.…”

“…As a result, the focus in the field has gradually shifted to developing a range of visible-light-responsive photocatalysts with a suitable band location, in order to address the above issues. 23–27…”