Influence of Morphology-Controlled Cu2ZnSnSe4 Nanoparticles for Environmental Remediation Process under Visible Light

Cu2ZnSnSe4 (CZTSe) nanoparticles (NPs) are successfully synthesized via cost-effective hot-injection process and morphologically modified by biphasic ligand exchange method. X-ray diffraction (XRD) results indicate kesterite phase for the as-prepared CZTSe NPs. Scherrer equation is used to evaluate the average crystallite size (approximate to 30 nm). Scanning electron microscopy (SEM) images reveal that the interconnected nanoflakes structure combines to produce hierarchical CZTSe nanoflower. Fourier-transform infrared spectroscopy (FTIR) results confirm the replacement of native long-chain ligand over the surface of NPs with inorganic salts. The optical studies reveal that the CZTSe NPs have a large absorbance over the visible region with optimum bandgap value of 1.23 eV. The photocatalytic studies confirm the high efficiency of CZTSe NPs in degrading the methylene blue (MB) dye within 120 min under visible light irradiation. The intermediate products formed during the degradation of MB have been analyzed by electrospray ionization mass spectrometry (ESI-MS). The photocatalytic degradation mechanism is discussed.