TY - JOUR
T1 - New approach of modifying the anatase to rutile transition temperature in TiO2 photocatalysts
AU - Byrne, Ciara
AU - Fagan, Rachel
AU - Hinder, Steven
AU - McCormack, Declan E.
AU - Pillai, Suresh C.
N1 - Publisher Copyright:
© 2016 The Royal Society of Chemistry.
PY - 2016
Y1 - 2016
N2 - In pure synthetic titanium dioxide, the anatase to rutile phase transition usually occurs between the temperatures of 600 °C and 700 °C. The phase transition temperature can be altered by various methods, including modifying the precursor or by adding dopant or modifier to the TiO2 sample. In an attempt to investigate the phase transition using aromatic carboxylic acids, the current study examines the impact of increasing concentrations of benzoic acid (1:0, 1:1, 1:4 and 1:8 molar ratio TiO2:benzoic acid) on anatase to rutile transition. The samples were characterised using Raman spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) studies. At 500 °C, all samples contained only anatase. At 600 °C, the 1:1, 1:4 and 1:8 samples contain only anatase and the control (which contains no modifier) was a mixture of 27% anatase and 73% rutile. At 700 °C, the 1:1 molar ratio sample contained 50% anatase/rutile, 1:4 and 1:8 molar ratio samples were observed to have a majority of anatase, 76% and 71% respectively. When the temperature was increased to 800 °C, the sample with the 1:4 molar ratio contained 10% anatase and at the same temperature the 1:8 ratio sample contained 7% anatase; the remaining samples (1:0 and 1:1) at this temperature contained only rutile. These results show that there is a significant % anatase still present when the doped samples were calcined to 700 °C when compared with the control (100% rutile). There are small amounts of the anatase phase in the 1:4 and 1:8 samples at 800 °C. Therefore, benzoic acid has induced a delay in the rutile formation.
AB - In pure synthetic titanium dioxide, the anatase to rutile phase transition usually occurs between the temperatures of 600 °C and 700 °C. The phase transition temperature can be altered by various methods, including modifying the precursor or by adding dopant or modifier to the TiO2 sample. In an attempt to investigate the phase transition using aromatic carboxylic acids, the current study examines the impact of increasing concentrations of benzoic acid (1:0, 1:1, 1:4 and 1:8 molar ratio TiO2:benzoic acid) on anatase to rutile transition. The samples were characterised using Raman spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) studies. At 500 °C, all samples contained only anatase. At 600 °C, the 1:1, 1:4 and 1:8 samples contain only anatase and the control (which contains no modifier) was a mixture of 27% anatase and 73% rutile. At 700 °C, the 1:1 molar ratio sample contained 50% anatase/rutile, 1:4 and 1:8 molar ratio samples were observed to have a majority of anatase, 76% and 71% respectively. When the temperature was increased to 800 °C, the sample with the 1:4 molar ratio contained 10% anatase and at the same temperature the 1:8 ratio sample contained 7% anatase; the remaining samples (1:0 and 1:1) at this temperature contained only rutile. These results show that there is a significant % anatase still present when the doped samples were calcined to 700 °C when compared with the control (100% rutile). There are small amounts of the anatase phase in the 1:4 and 1:8 samples at 800 °C. Therefore, benzoic acid has induced a delay in the rutile formation.
UR - http://www.scopus.com/inward/record.url?scp=84991278558&partnerID=8YFLogxK
U2 - 10.1039/c6ra19759k
DO - 10.1039/c6ra19759k
M3 - Article
AN - SCOPUS:84991278558
SN - 2046-2069
VL - 6
SP - 95232
EP - 95238
JO - RSC Advances
JF - RSC Advances
IS - 97
ER -