Inception and Evolution of Nitrogen Sorption Hysteresis Loops by Thermally-Induced Nanopore Drilling in TiO Xerogel Microspheres: UV Photoreduction of Methyl Orange
Titanium dioxide (TiO 2 ) microspheres were prepared via a sol–gel route and the textural properties of these substrates developed through thermal treatment performed between 100 °C and 500 °C which led to the decomposition of organic groups and sintering between microparticles. The annealed TiO 2 m...
Saved in:
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
SAGE Publishing
2009-04-01
|
| Series: | Adsorption Science & Technology |
| Online Access: | https://doi.org/10.1260/026361709789868893 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1841564511472975872 |
|---|---|
| author | Celso Velásquez M. Luisa Ojeda Antonio Campero J. Javier Sánchez-Mondragón J. Marcos Esparza Fernando Rojas |
| author_facet | Celso Velásquez M. Luisa Ojeda Antonio Campero J. Javier Sánchez-Mondragón J. Marcos Esparza Fernando Rojas |
| author_sort | Celso Velásquez |
| collection | DOAJ |
| description | Titanium dioxide (TiO 2 ) microspheres were prepared via a sol–gel route and the textural properties of these substrates developed through thermal treatment performed between 100 °C and 500 °C which led to the decomposition of organic groups and sintering between microparticles. The annealed TiO 2 microglobules enclosed a nanopore network consisting of alternating bulges and throats. The nitrogen adsorption isotherms of the TiO 2 xerogels treated at 100 °C and 500 °C possessed very narrow hysteresis loops, whereas the corresponding adsorption isotherms of the TiO 2 microglobular samples annealed at 200–400 °C showed well-defined hysteresis cycles. The UV catalytic photoreduction of Methyl Orange solutions in the presence of porous TiO 2 microspheres occurred to a significant extent regardless of the annealing temperature employed; anatase was present between 200 °C and 500 °C while the appearance of rutile started from 350 °C onwards. Electron release took place from the external area of the microglobules rather than from the surface of the internal pores of the microspheres; as a consequence, significant photocatalytic activity was displayed by all the samples. Two concomitant effects influenced the properties of a given TiO 2 sample: (i) an increase in the annealing temperature led to a higher crystallinity; and (ii) the surface area and porosity decreased with temperature due to increased sintering. |
| format | Article |
| id | doaj-art-fdd93b673abd470cb822e41b11490cfd |
| institution | Kabale University |
| issn | 0263-6174 2048-4038 |
| language | English |
| publishDate | 2009-04-01 |
| publisher | SAGE Publishing |
| record_format | Article |
| series | Adsorption Science & Technology |
| spelling | doaj-art-fdd93b673abd470cb822e41b11490cfd2025-01-02T22:39:32ZengSAGE PublishingAdsorption Science & Technology0263-61742048-40382009-04-012710.1260/026361709789868893Inception and Evolution of Nitrogen Sorption Hysteresis Loops by Thermally-Induced Nanopore Drilling in TiO Xerogel Microspheres: UV Photoreduction of Methyl OrangeCelso Velásquez0M. Luisa Ojeda1Antonio Campero2J. Javier Sánchez-Mondragón3J. Marcos Esparza4Fernando Rojas5 Departamento de Ciencias Naturales y Exactas, Universidad de Guadalajara, Centro Universitario de los Valles, C.P. 46600, Ameca, Jalisco, Mexico Departamento de Ciencias Naturales y Exactas, Universidad de Guadalajara, Centro Universitario de los Valles, C.P. 46600, Ameca, Jalisco, Mexico Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, P.O. Box 55-534, Mexico, D.F. Mexico Laboratorio de Fotónica y Física Óptica, Instituto Nacional de Astrofísica, Óptica y Electrónica, Tonantzintla, Puebla 72000, Mexico Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, P.O. Box 55-534, Mexico, D.F. Mexico Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, P.O. Box 55-534, Mexico, D.F. MexicoTitanium dioxide (TiO 2 ) microspheres were prepared via a sol–gel route and the textural properties of these substrates developed through thermal treatment performed between 100 °C and 500 °C which led to the decomposition of organic groups and sintering between microparticles. The annealed TiO 2 microglobules enclosed a nanopore network consisting of alternating bulges and throats. The nitrogen adsorption isotherms of the TiO 2 xerogels treated at 100 °C and 500 °C possessed very narrow hysteresis loops, whereas the corresponding adsorption isotherms of the TiO 2 microglobular samples annealed at 200–400 °C showed well-defined hysteresis cycles. The UV catalytic photoreduction of Methyl Orange solutions in the presence of porous TiO 2 microspheres occurred to a significant extent regardless of the annealing temperature employed; anatase was present between 200 °C and 500 °C while the appearance of rutile started from 350 °C onwards. Electron release took place from the external area of the microglobules rather than from the surface of the internal pores of the microspheres; as a consequence, significant photocatalytic activity was displayed by all the samples. Two concomitant effects influenced the properties of a given TiO 2 sample: (i) an increase in the annealing temperature led to a higher crystallinity; and (ii) the surface area and porosity decreased with temperature due to increased sintering.https://doi.org/10.1260/026361709789868893 |
| spellingShingle | Celso Velásquez M. Luisa Ojeda Antonio Campero J. Javier Sánchez-Mondragón J. Marcos Esparza Fernando Rojas Inception and Evolution of Nitrogen Sorption Hysteresis Loops by Thermally-Induced Nanopore Drilling in TiO Xerogel Microspheres: UV Photoreduction of Methyl Orange Adsorption Science & Technology |
| title | Inception and Evolution of Nitrogen Sorption Hysteresis Loops by Thermally-Induced Nanopore Drilling in TiO Xerogel Microspheres: UV Photoreduction of Methyl Orange |
| title_full | Inception and Evolution of Nitrogen Sorption Hysteresis Loops by Thermally-Induced Nanopore Drilling in TiO Xerogel Microspheres: UV Photoreduction of Methyl Orange |
| title_fullStr | Inception and Evolution of Nitrogen Sorption Hysteresis Loops by Thermally-Induced Nanopore Drilling in TiO Xerogel Microspheres: UV Photoreduction of Methyl Orange |
| title_full_unstemmed | Inception and Evolution of Nitrogen Sorption Hysteresis Loops by Thermally-Induced Nanopore Drilling in TiO Xerogel Microspheres: UV Photoreduction of Methyl Orange |
| title_short | Inception and Evolution of Nitrogen Sorption Hysteresis Loops by Thermally-Induced Nanopore Drilling in TiO Xerogel Microspheres: UV Photoreduction of Methyl Orange |
| title_sort | inception and evolution of nitrogen sorption hysteresis loops by thermally induced nanopore drilling in tio xerogel microspheres uv photoreduction of methyl orange |
| url | https://doi.org/10.1260/026361709789868893 |
| work_keys_str_mv | AT celsovelasquez inceptionandevolutionofnitrogensorptionhysteresisloopsbythermallyinducednanoporedrillingintioxerogelmicrospheresuvphotoreductionofmethylorange AT mluisaojeda inceptionandevolutionofnitrogensorptionhysteresisloopsbythermallyinducednanoporedrillingintioxerogelmicrospheresuvphotoreductionofmethylorange AT antoniocampero inceptionandevolutionofnitrogensorptionhysteresisloopsbythermallyinducednanoporedrillingintioxerogelmicrospheresuvphotoreductionofmethylorange AT jjaviersanchezmondragon inceptionandevolutionofnitrogensorptionhysteresisloopsbythermallyinducednanoporedrillingintioxerogelmicrospheresuvphotoreductionofmethylorange AT jmarcosesparza inceptionandevolutionofnitrogensorptionhysteresisloopsbythermallyinducednanoporedrillingintioxerogelmicrospheresuvphotoreductionofmethylorange AT fernandorojas inceptionandevolutionofnitrogensorptionhysteresisloopsbythermallyinducednanoporedrillingintioxerogelmicrospheresuvphotoreductionofmethylorange |