One-Step Hydrothermal Synthesis of Cu2ZnSnS4 Nanoparticles as an Efficient Visible Light Photocatalyst for the Degradation of Congo Red Azo Dye

Abstract

A hydrothermal method was successfully employed to synthesize kesterite Cu2ZnSnS4 (CZTS) nanoparticles. X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and optical ultraviolet-visible (UV-vis) spectroscopy were used for characterization of structural, chemical, morphological, and optical properties. XRD results confirmed that a nanocrystalline CZTS phase corresponding to the kesterite structure was formed. Raman analysis confirmed the existence of single pure phase CZTS. XPS results revealed the oxidation states as Cu+, Zn2+, Sn4+, and S2−. FESEM and TEM micrograph images revealed the presence of nanoparticles with average sizes between 7 nm to 60 nm. The synthesized CZTS nanoparticles bandgap was found to be 1.5 eV which is optimal for solar photocatalytic degradation applications. The properties as a semiconductor material were evaluated through the Mott–Schottky analysis. The photocatalytic activity of CZTS has been investigated through photodegradation of Congo red azo dye solution under solar simulation light irradiation, proving to be an excellent photo-catalyst for CR where 90.2% degradation could be achieved in just 60 min. Furthermore, the prepared CZTS was reusable and can be repeatedly used to remove Congo red dye from aqueous solutions.

Exploring the Bifunctionality of Co3S4/NiS2/Cu2S Heterojunction Nanocomposites for Hybrid Supercapacitors and Double Z-Scheme-Driven Dye Degradation

“…The rate constants were calculated to be 0.0233, 0.0156, 0.0113, and 0.0081 min –1 for the CR initial concentrations of 20, 40, 60, and 100 mg L –1 , respectively. The time-dependent absorption spectra (Figure d) show a characteristic peak at 510 nm due to the n-π* transition of the azo group . The progressive decrease of the absorption peak with illumination time confirms the visible light-facilitated degradation of CR, which could be seen from the inset image of Figure d displaying the decolorization of CR with time.…”

“…Figure S4 (Supporting Information) shows the excellent stability of CNCS-0.15 for five successive cycles with less than a 5% decrease from its initial activity. For a comparative analysis, Table S3 compiles the degradation ability of CR using other binary/ternary catalysts which signifies the potential of CNCS-0.15 for real-time remediation of dyes and other pollutants. ,,− …”

Solvothermal Synthesis of Cu2ZnSnSe4 Nanoparticles and Their Visible-Light-Driven Photocatalytic Activity

“…CZTSe-NPs were characterized by different techniques that provided information about their structural and chemical composition and morphological, optical, and optoelectronic properties. These characterizations were performed as previously reported by our group [33] (see also Supplementary Material SI).…”

“…To establish the photodegradation of dye and the regeneration of the CZTSe-NP photocatalyst, studies were carried out employing a 50 mL solution of 0.04 mM Congo red azo dye, to which 35 mg of Cu 2 ZnSnSe 4 nanoparticles were added. The studies were performed as previously reported by our group [33] (see also Supplementary Material SI).…”

“…Due to their adequate nature and outstanding optoelectronic properties (as has been said and described above), researchers are encouraged to work on kesterite semiconductor materials as a suitable candidate in the field of semiconductor photocatalysis [12,23,24]. In fact, in recent years, the CZTS semiconducting photocatalyst compound has been well documented and intensively studied in water remediation of organic pollutants and industrial wastes [13,[25][26][27][28][29][30][31][32][33][34]. However, until now, there have been few works reporting the employment of the CZTSe compound as a semiconducting photocatalytic material.…”