Thermal evolution of structure and photocatalytic activity in polymer microsphere templated TiO2 microbowls

Abstract

a b s t r a c tPolystyrene cross-linked divinyl benzene (PS-co-DVB) microspheres were used as an organic template in order to synthesize photocatalytic TiO 2 microspheres and microbowls. Photocatalytic activity of the microbowl surfaces were demonstrated both in the gas phase via photocatalytic NO(g) oxidation by O 2 (g) as well as in the liquid phase via Rhodamine B degradation. Thermal degradation mechanism of the polymer template and its direct influence on the TiO 2 crystal structure, surface morphology, composition, specific surface area and the gas/liquid phase photocatalytic activity data were discussed in detail. With increasing calcination temperatures, spherical polymer template first undergoes a glass transition, covering the TiO 2 film, followed by the complete decomposition of the organic template to yield TiO 2 exposed microbowl structures. TiO 2 microbowl systems calcined at 600 • C yielded the highest per-site basis photocatalytic activity. Crystallographic and electronic properties of the TiO 2 microsphere surfaces as well as their surface area play a crucial role in their ultimate photocatalytic activity. It was demonstrated that the polymer microsphere templated TiO 2 photocatalysts presented in the current work offer a promising and a versatile synthetic platform for photocatalytic DeNO x applications for air purification technologies.

Photocatalytic Activity of Mesoporous Graphitic Carbon Nitride (mpg-C3N4) Towards Organic Chromophores Under UV and VIS Light Illumination

“…In a typical photocatalytic degradation experiment [3,4], a suspension of mpg-C 3 N 4 powder in deionized water was prepared. After sonication of the prepared aqueous suspension for 20 min, an appropriate amount of dye (RhB, MO, BCP or MB) from its 60 mg L -1 stock solution was added to the mixture in order to have a final dye concentration of 10 mg L -1 .…”

“…Functional materials synthesized by utilizing novel preparation strategies can be promising photocatalytic platforms that harvest renewable solar energy in order to eliminate hazardous industrial contaminants through energy-efficient pathways. Such economic and technological opportunities led to a rapid growth in the research focusing on photocatalytic materials in the recent decades [1][2][3][4][5]. Among such photocatalytic architectures, graphitic carbon nitride (g-C 3 N 4 ) that is the most stable allotrope of carbon nitride at ambient atmosphere stands out as one of the strong contenders in the photocatalytic air and water purification processes owing to its advantageous properties such as being cost-efficient, abundant, non-toxic, metal-free, and stable nature under ambient conditions with a low electronic band gap falling in the visible (VIS) range of the solar spectrum.…”

Influence of the sol–gel preparation method on the photocatalytic NO oxidation performance of TiO2/Al2O3 binary oxides

“…A custom-design photocatalytic flow reactor system was used in the photocatalytic activity measurements [33,37]. The flow reactor system consisted of a gas manifold system, mass flow controllers (MKS 1479A), a capacitance pressure gauge (MKS Baratron 622B), a custom-made photocatalytic reactor and a chemiluminescence NO x analyzer (Horiba APNA 370).…”

Hierarchical synthesis of corrugated photocatalytic TiO2 microsphere architectures on natural pollen surfaces

“…One of the most abundant renewable energy sources that can be exploited in heterogeneous catalysis applications in an environmentally friendly and economical manner is the solar energy. Thus, there exists an immense demand to develop novel photocatalytic materials using innovative synthetic methodologies [6][7][8][9][10][11].…”