Photocatalytic degradation of Rhodamine B dye using low‐cost pyrofabricated titanium dioxide quantum dots‐kaolinite nanocomposite

• Published in: Applied organometallic chemistry Vol. 37; no. 7
• Main Authors: Awad, Mahmoud E., Farrag, Amr M., El‐Bindary, Ashraf A., El‐Bindary, Mohamed A., Kiwaan, Hala A.
• Format: Journal Article
• Language: English
• Published: Chichester Wiley Subscription Services, Inc 01-07-2023
• Subjects: Aqueous solutions; Chemistry; Conduction bands; Differential thermal analysis; Dyes; Energy gap; Kaolinite; Nanocomposites; Photocatalysis; Photocatalysts; photocatalytic degradation; Photodegradation; Potential energy; pyrofabrication; Quantum dots; Rhodamine; scavenger; TiO2 quantum dots; Titanium; Titanium dioxide; X ray photoelectron spectroscopy
• ISSN: 0268-2605; 1099-0739
• DOI: 10.1002/aoc.7113

In this study, we report a simple technique for the pyrofabrication of a novel photocatalyst of titanium dioxide quantum dots‐kaolinite nanocomposite (TiO2‐QDs‐Kao) used for rhodamine B (RhB) dye degradation. The photocatalyst was characterized by using different analytical techniques, including XRD, XRF, XPS, FTIR, DTA/TGA, SEM–EDX, TEM, BET, BJH, ZP and UV–Vis DRS. The photocatalytic degradation of RhB was performed in aqueous solutions using the sustainable sunlight energy under atmospheric conditions and fixed neutral medium (pH = 7). The produced photocatalyst exhibited optical band gap energy of 2.85 eV, an improved large specific surface area of 107.724 m2/g with pore radius of 1.45 nm and total pore volume of 0.123 cm3/g. The study indicated a maximum 91% degradation efficiency of RhB after 120 min using the optimum dose 1,400 mg/l of the TiO2‐QDs‐Kao photocatalyst. The degradation of RhB dye fitted the Langmuir first‐order kinetics with rate constant 0.0151 min−1. The radical trapping experiments based on scavengers confirmed that the mechanism of photocatalytic degradation activity was potentially based on electron (e−) and hole (h+) conduction band. The potential energy of the valence and conduction bands EVB and ECB were calculated 2.73 and −0.12 eV, respectively. A triple reusability study confirmed a high stability of TiO2‐QDs‐Kao photocatalyst with detected degradation efficiencies of 91.0, 89.9, 88.8 and 87.5%, respectively.
A simple technique for the pyrofabrication of a novel photocatalyst of titanium dioxide quantum dots‐kaolinite nanocomposite (TiO2‐QDs‐Kao) used for rhodamine B (RhB) dye degradation as a model organic contaminant. The pyrofabricated TiO2‐QDs‐Kao nanocomposite product was characterized by using different spectroscopic techniques. The study indicated a maximum 91% degradation efficiency of RhB after 120 min using the optimum dose 1,400 mg/l of the TiO2‐QDs‐Kao nanocomposite photocatalyst. The degradation of RhB dye fitted the Langmuir first‐order kinetics with rate constant 0.0151 min−1. The radical trapping experiments based on scavengers confirmed that the mechanism of photocatalytic degradation activity was potentially based on electron (e−) and hole (h+) conduction band.