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

Abstract

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 photocur-rent 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 ex-periments and Mott-Schottky analysis revealed that the superoxide radicals (•O − 2) 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.

Enhanced Photocatalytic Degradation of Ternary Dyes by Copper Sulfide Nanoparticles

“…Three different scavengers were used to investigate the photocatalytic degradation mechanism of the as-prepared CuS. Sodium sulfate (NaS, e − scavenger), sodium oxalate (NaOx h + scavenger), acrylamide (AC, • O 2 − scavenger), and isopropanol (IPA, • OH scavenger) [ 65 ]. Figure 8 shows the scavenging activity of the as-prepared CuS nanoparticles over each dye and mixed dyes.…”

“…In contrast, e − reacts with • O 2 − in the air to form (superoxide radical). The generated • OH and • O 2 − radical directly react with the dyes oxidizing them into smaller molecules [ 65 ].…”

Selectivity Enhancement for Uric Acid Detection via In Situ Preparation of Blue Emissive Carbon Dots Entrapped in Chromium Metal–Organic Frameworks

“…Synthesis of bCDs@Cr-MOFs. The bCDs@Cr-MOFs were synthesized via the hydrothermal method according to a previous procedure 39 with modifications. Typically, 0.8 g of Cr(NO 3 ) 3 •9H 2 O was added into 30 mL of distilled water containing 0.2 g of NaOH and sonicated for 30 min.…”

Integration of MIL-101-NH2 into Cellulosic Foams for Efficient Cr(VI) Reduction under Visible Light

“…MOFs display outstanding characteristics of desirable topology, high surface areas, along with a tunable band gap as compared to the traditional photocatalysts . As a subclass of MOFs, MILs (Matériaux de Institut Lavoisier) have been widely explored in photocatalytic applications. , In particular, Fe-based MILs have embarked extensive interest because of their high activity, abundant porosity, and good stability. For example, the tunable Fe-based metal–organic framework prepared by Li et al exhibited a toluene catalytic removal efficiency of 100% .…”