Tuning the band gap of manganese telluride quantum dots (MnTe QDs) for photocatalysis

Chowde Gowda, C and Chandravanshi, D and Tromer, RM and Malya, A and Chattopadhyay, K and Galvão, DS and Tiwary, CS (2024) Tuning the band gap of manganese telluride quantum dots (MnTe QDs) for photocatalysis. In: Applied Physics A: Materials Science and Processing, 130 (5).

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Abstract

Laser ablation synthesis in solution (LASiS) was used to synthesize quantum dots (QDs) of manganese telluride (MnTe). Size-tuneable QDs exhibit physicochemical property variation in the bandgap, optical, electrical, and magnetic properties. The size of QDs was fine-tuned with varying power and time duration of laser ablation. The characteristics of MnTe QDs were investigated using basic structural and morphological characterizations. The observed bandgap opening in the material is due to the quantum confinement effect, which led to increased energy band separation, as predicted from DFT simulations. The magnetic property of the synthesized MnTe QD catalysts influences the degradation process, with the process following pseudo-first-order kinetics. The photocatalytic dye degradation was studied using UV�visible spectroscopy. MnTe QDs were able to photodegrade methylene blue reagent up to 93.4 in 60 min under an external magnetic field. The magnetic field-induced MnTe QDs showed enhanced photocatalytic degradation efficiency with increased apparent rate kinetics up to ten times (0.0453 min�1) compared to just sunlight exposure (0.00456 min�1). Graphical Abstract: (a) HAADF-STEM of the synthesized MnTe QD dispersed, (b) SEM image of the same, (c) relative concentration of the samples with and without magnetic fields, inset: photo degraded samples on exposure of magnetic fields and (d) schematic representation of the photocatalytic dye-degradation. (Figure presented.) © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.

Item Type:	Journal Article
Publication:	Applied Physics A: Materials Science and Processing
Publisher:	Springer Science and Business Media Deutschland GmbH
Additional Information:	The copyright for this article belongs to Springer Science and Business Media Deutschland GmbH.
Keywords:	Aromatic compounds; Degradation; Energy gap; Magnetic fields; Magnetic properties; Manganese compounds; Nanocrystals; Photocatalytic activity; Physicochemical properties; Semiconductor quantum dots, Field-induced; Induced degradation; Laser ablation in solution; Lasers ablations; Magnetic field induced degradation; Magnetic-field; Manganese telluride; Photocatalytic dye degradations; Quantum dot; Synthesised, Laser ablation
Department/Centre:	Division of Interdisciplinary Sciences > Interdisciplinary Centre for Energy Research Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy) Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering
Date Deposited:	10 Jul 2024 06:13
Last Modified:	10 Jul 2024 06:13
URI:	http://eprints.iisc.ac.in/id/eprint/84770

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