Nghiên cứu tổng hợp vật liệu CuInS2 ứng dụng làm xúc tác quang để xử lý Cr (VI) trong môi trường nước

Chromium(VI) pollution in water represents a significant environmental threat due to its high toxicity and widespread industrial discharge. Photocatalysis emerges as a highly promising and environmentally friendly strategy for the efficient degradation of such pollutants. Copper Indium Sulfide (CuInS2) materials are particularly attractive for this application, possessing favorable optical properties like a high absorption coefficient and a suitable band gap of 1.09 eV. However, inherent limitations such as low specific surface area and rapid electron-hole recombination often hinder their practical efficiency. This research addresses these challenges by synthesizing CuInS2 materials through a controlled hydrothermal method and rigorously evaluating their photocatalytic performance for the effective treatment of Cr(VI) in aqueous environments, with a focus on enhancing its activity through improved charge separation.

Researchers in materials science, environmental chemistry, chemical engineering, and students interested in photocatalysis and water treatment technologies.

This study details the successful synthesis of Copper Indium Sulfide (CuInS2) materials using a straightforward hydrothermal method, aiming to develop an effective photocatalyst for chromium(VI) remediation. The synthesized CuInS2 materials were thoroughly characterized using various analytical techniques. X-ray diffraction (XRD) confirmed the chalcopyrite structure with characteristic peaks, while scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed uniformly distributed, plate-like and flower-like nanoparticles approximately 1 µm in size. Photoelectrochemical analyses, including UV-Vis DRS, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS), demonstrated the material's strong visible light absorption, suitable band gap of 1.09 eV, and efficient charge separation and transfer capabilities, all critical for high photocatalytic activity. The photocatalytic performance of CuInS2 was rigorously evaluated for the degradation of Cr(VI) in aqueous solutions under visible light irradiation. Experimental results showed that the photocatalytic activity was significantly influenced by initial Cr(VI) concentration and catalyst loading. Under optimized conditions – specifically, a 30 ppm Cr(VI) solution with 30 mg of CuInS2 catalyst – an impressive removal efficiency of 96% was achieved within 120 minutes. Higher catalyst loadings were found to decrease efficiency due to light shielding effects, highlighting the importance of optimal material usage. This research successfully demonstrates that hydrothermally synthesized CuInS2 is a highly effective and promising photocatalyst for environmental remediation, particularly for reducing toxic Cr(VI) to less harmful forms, offering a viable solution for water purification.