Published May 2021 | Version v1
Journal article Metadata-only

Photocatalytic and thermolytic "Attenuation – Degradation" mechanisms of perfluoroalkylsilane self assembled on TiO2 nanoparticles

Creators

  • 1. Nanosciences and Technology, Karunya Institute of Technology and Sciences, Coimbatore 641114, Tamil Nadu (India)
  • 2. InCUBE-EngSciRes R&D, Alpha Academy Tech(R), Udumalpet, Coimbatore, Tamil Nadu 642126 (India)
  • 3. Department of Mechanical Engineering, Applied Research Lab, School of Mechanical Engineering, Vellore Institute of Technology, Chennai 600127, Tamil Nadu (India)

Description

Highlights: • FOTS SAM increases bandgap of TiO2-NPs and attenuates UV induced electron-hole pair. • FOTS SAM suppresses ROS species and attenuate photocatalytic properties of TiO2-NPs. • FOTS SAM coating converts hydrophilic TiO2-NPs into super hydrophobic. • FOTS SAM-TiO2-NPs become hydrophilic under long exposure to UV and high temperature. • FOTS-SAM acts as photocatalytic and thermolytic attenuation layer. • FOTS SAM-TiO2-NPs filled PLLA shows enhanced mechanical properties and stability. In this work, we studied photocatalytic and thermolytic "attenuation-degradation" mechanisms of 1H, 1H, 2H, 2H - perfluorooctyltrichlorosilane (FOTS-SAM) coated titanium dioxide nanoparticles (TiO2-NPs). During thermolytic analysis, FOTS-SAM on TiO2-NPs was very stable up to 300 °C and further increase of temperature to 450 °C caused conformational disorders and the disorders increased up to 550 °C and complete degradation and desorption of FOTS-SAM from TiO2-NPs occurred above 550 °C. During photocatalytic analysis, FOTS-SAM on TiO2-NPs was stable up to 3 hrs and further UV exposure caused increase of conformational disorders up to 12 hrs and after 15 hrs complete degradation and desorption of FOTS-SAM from the TiO2-NPs. It is observed that FOTS-SAM surface modification (i) passivates TiO2-NPs (ii) increases band gap from 3.2 eV to 5.7 eV and (iii) attenuates UV induced electron-hole pair (e−, h+) generation. Further observed that the FOTS-SAM-TiO2-NPs were superhydrophobic but under long UV exposure and high temperature they became hydrophilic. PLLA-nanocomposites filled with FOTS-SAM-TiO2-NPs show excellent mechanical properties and stability compared to PLLA-nanocomposites filled with uncoated TiO2-NPs. Experimental investigations confirm that FOTS-SAM on TiO2-NPs acts as photocatalytic and thermolytic attenuation layer, super hydrophobic layer and enhances stability and mechanical properties of nanocomposites.

Availability note (English)

Available from http://dx.doi.org/10.1016/j.apsusc.2021.149278

Additional details

Identifiers

DOI
10.1016/j.apsusc.2021.149278;
PII
S0169433221003548;

Publishing Information

Journal Title
Applied Surface Science
Journal Volume
549
Journal Page Range
vp.
ISSN
0169-4332
CODEN
ASUSEE

INIS

Country of Publication
Netherlands
Country of Input or Organization
International Atomic Energy Agency (IAEA)
INIS RN
54080742
Subject category
S75: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY;
Descriptors DEI
ATTENUATION; FLUORINE COMPOUNDS; HYDROGEN IONS 1 PLUS; LAYERS; MECHANICAL PROPERTIES; NANOPARTICLES; PHOTOCATALYSIS; TITANIUM OXIDES
Descriptors DEC
CATALYSIS; CATIONS; CHALCOGENIDES; CHARGED PARTICLES; HALOGEN COMPOUNDS; HYDROGEN IONS; IONS; OXIDES; OXYGEN COMPOUNDS; PARTICLES; TITANIUM COMPOUNDS; TRANSITION ELEMENT COMPOUNDS

Optional Information

Copyright
Copyright (c) 2021 Elsevier B.V. All rights reserved.