Modulation of Pore Sizes of Titanium Dioxide Photocatalysts by a Facile Template Free Hydrothermal Synthesis Method: Implications for Photocatalytic Degradation of Rhodamine B

Abstract

Mesoporous TiO2 photocatalysts were prepared in ethanol media by using relatively green, template free sol-gel technique. A mild hydrothermal treatment procedure was employed to tune the pore sizes of the materials. Comprehensive techniques that include powder X-ray diffraction, diffuse reflectance spectroscopy, specific surface area analysis, electron microscopy, FT-IR, TGA, and ζ-potential measurements were used to characterize the titania materials. Porosity (pore size and pore volume) of the materials were found to be key factors for the variation in the rate of photocatalytic degradation of rhodamine B; in addition to specific surface area, and surface hydroxyl groups. An increase in porosity permits effective transport of the dye molecules resulting in an increase in the rate of the degradation in materials having larger pores. A detailed electrospray ionization-mass spectrometric (ESI-MS) study was carried out for selected materials to identify photodegraded intermediates and products formed during the degradation of rhodamine B. In addition, experiments were also carried out to understand the role of reactive oxygen species (ROS). In summary, this work provides a simple way to tune pore sizes without the use of any template and an insight into the influence of pore size for the photocatalytic degradation of rhodamine B.

One dimensional CdS nanowire@TiO2 nanoparticles core-shell as high performance photocatalyst for fast degradation of dye pollutants under visible and sunlight irradiation

“…So, with increasing of organic dyes usage, the elimination of dyes from wastewaters has become a necessity. Among various organic dyes, methyl orange (MO), methylene blue (MB) and rhodamine B (Rh B) are the largest group of colorants used in color printing, foodstuffs, textile dyeing, leather industries, pharmaceutical and research laboratories [2][3][4][5][6]. So, wastewaters containing MO, MB and Rh B have become one of the most pressing of environmental problems, because presence of organic dyes exerts adverse effects on people's lives and upon the ecosystem [2][3][4][5][6][7][8][9][10][11].…”

“…Among various organic dyes, methyl orange (MO), methylene blue (MB) and rhodamine B (Rh B) are the largest group of colorants used in color printing, foodstuffs, textile dyeing, leather industries, pharmaceutical and research laboratories [2][3][4][5][6]. So, wastewaters containing MO, MB and Rh B have become one of the most pressing of environmental problems, because presence of organic dyes exerts adverse effects on people's lives and upon the ecosystem [2][3][4][5][6][7][8][9][10][11]. Furthermore, MO, MB and Rh B dyes are mutagenic and carcinogenic and they can cause the death of lung tissues, fast heart rate and vomiting [2][3][4][5][6][7][8][9][10][11].…”

Effect of Erbium on the Photocatalytic Activity of TiO2/Ag Nanocomposites under Visible Light Irradiation

“…The rate of photodegradation of dye catalyzed by titania composites depends on the concentration of Rhodamine B and follows a pseudo‐first‐order reaction given in Equations (2) and (3):44 …”

Metal recovery based magnetite near-infrared photocatalyst with broadband spectrum utilization property

“…The NIR energy is mainly absorbed by the sensitizers of Yb 3+ ions, and then the absorbed energy transfers from Yb 3+ to Er 3+ and Tm 3+ to emit the red (656 nm), green (541 and 523 As shown in Table S2, the difference between the BET surface areas of CZ and ETY-FCZ is not obvious, whereas the average pore size of ETY-FCZ is larger than that of CZ, meaning the higher amounts of MO or SA molecules can be accommodated in ETY-FCZ. The higher pore volume of ETY-FCZ can also result in the more efficient transport pathways compared to CZ for the molecular trafficking [38]. These textural properties of ETY-FCZ are favorable for the improvement of the photocatalytic activities.…”