Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance work on Wednesday 21st October 2020 from 07:00 AM to 07:00 PM (BST).

During this time our website performance may be temporarily affected. We apologise for any inconvenience this might cause and thank you for your patience.


Issue 109, 2016, Issue in Progress
Previous Article Next Article

Irreversible phase transition in BiVO4 nanostructures synthesized by a polyol method and enhancement in photo degradation of methylene blue

Author affiliations

Abstract

Structure and bonding in metal oxides has been studied extensively using Raman vibrational spectroscopy and is found to provide complementary information to the crystallographic observations. In this study, BiVO4 nanostructures with pure and stable crystal phases were synthesized selectively by reaction between Bi(NO3)3·5H2O and NH4VO3 in ethylene glycol at temperatures between 80 °C to 140 °C. A high temperature tetragonal scheelite (t-s) phase was obtained directly at synthesis temperature, whereas calcination at 600 °C resulted in phase transformation to a monoclinic scheelite (m-s) crystal structure. Distortion of the VO43− tetrahedron, being the reason for the phase transition that results in two sets of V–O bonds, was confirmed by bond length and bond strength calculations with the help of Raman spectroscopy. Irreversibility of the phase transition was observed through Differential Scanning Calorimetric (DSC) analysis and X-Ray Diffraction (XRD). The band gap was found to vary between 1.97 to 2.33 eV with respect to synthesis temperature as well as calcination temperature. Nanostructures synthesized at 110 °C and calcined at 600 °C for 3 h had a band gap of 2.25 eV and were found to bring about the highest photocatalytic degradation of MB under visible light irradiation. Increase in the distortion of the VO43− tetrahedron in terms of increase in the difference between bond lengths of two sets of V–O bonds was found to be the reason for the enhancement in the photodegradation of MB over BiVO4 catalysts with a monoclinic scheelite crystal structure.

Graphical abstract: Irreversible phase transition in BiVO4 nanostructures synthesized by a polyol method and enhancement in photo degradation of methylene blue

Back to tab navigation

Supplementary files

Article information


Submitted
06 Jun 2016
Accepted
04 Nov 2016
First published
10 Nov 2016

RSC Adv., 2016,6, 107463-107474
Article type
Paper

Irreversible phase transition in BiVO4 nanostructures synthesized by a polyol method and enhancement in photo degradation of methylene blue

S. Nikam and S. Joshi, RSC Adv., 2016, 6, 107463
DOI: 10.1039/C6RA14700C

Social activity

Search articles by author

Spotlight

Advertisements