Amino-functionalized MIL-101(Cr) photodegradation enhancement by sulfur-enriched copper sulfide nanoparticles: An experimental and DFT study

• Published in: Journal of molecular liquids 2020-12, Vol.319, p.114341, Article 114341
• Main Authors: Abdpour, Soheil, Kowsari, Elaheh, Bazri, Behrouz, Moghaddam, Mohammad Reza Alavi, Tafreshi, Saeedeh Sarabadani, de Leeuw, Nora H., Simon, Ilka, Schmolke, Laura, Dietrich, Dennis, Ramakrishna, Seeram, Janiak, Christoph
• Format: Article
• Language: English
• Subjects: Copper sulfide nanoparticles; Density functional theory calculations; Direct Z-scheme mechanism; Metal-organic frameworks; Photocatalyst; Rhodamine B
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2020.114341

In the present work, a direct Z-scheme composite photocatalyst, NH2-MIL-101(Cr)@CuS, with high photodegradation efficiency of Rhodamine B (RhB) degradation in the visible light spectrum, is fabricated through a solvothermal method. It was found that the NH2-MIL-101(Cr)@CuS composite with an appropriate amount of NH2-MIL-101(Cr) exhibited high catalytic performance in the RhB photodegradation. The photocurrent density and results from the electrochemical impedance spectroscopy (EIS) analysis confirm the promoted photocatalytic activity of the NH2-MIL-101(Cr)@CuS composite compared to the pristine MIL-101(Cr) and CuS nanoparticles, which were supported by the electron lifetime (τn) calculations for the samples. The trapping experiments and Mott-Schottky analysis revealed that the superoxide radicals (O2−) played an essential role in the photodegradation of RhB and the promoted photocatalytic activity contributed to a direct Z-scheme mechanism between CuS and NH2-MIL-101(Cr). Stability study also shows acceptable results during photocatalytic reaction. Furthermore, Density Functional Theory (DFT) calculations were performed to gain a better understanding of the electronic properties of the NH2-MIL-101(Cr)@CuS nanocomposite. The calculated band structures showed that the nanocomposite has a higher photocatalytic efficiency in the visible region compared to the pristine MIL-101(Cr) and CuS. The calculated band gap of both the semiconductors and the hybrid nanocomposite confirms the experimental results. •Synthesis novel NH2-MIL-101(Cr)@CuS photocatalyst with direct Z-scheme mechanism•Electrochemical analysis revealed the role of CuS in activation of NH2-MIL-101(Cr).•Electron lifetime (τn) calculation confirmed efficiency of NH2-MIL-101(Cr)@CuS.•DFT calculations confirm the experimental study of band structures of samples.