Details
| Original language | English |
|---|---|
| Pages (from-to) | 422-433 |
| Number of pages | 12 |
| Journal | Applied Catalysis B: Environmental |
| Volume | 238 |
| Early online date | 17 Jul 2018 |
| Publication status | Published - 15 Dec 2018 |
Abstract
An active TiO 2 for co-catalyst-free photocatalytic hydrogen evolution was successfully synthesized employing a simple Evaporation-Induced Self-Assembly (EISA) method that was developed and optimized with the help of Design of Experiment (DoE) coupled with Full Factorial Design (FFD) methodology. Coupling DoE with FFD provides a statistical tool for optimizing the synthesis process while carrying out the smallest number of experiments. This tool builds a statistical framework to determine the significance of the studied factors, i.e., titanium-precursor type, surfactant type and surfactant quantity, along with their potential interactions, as well as with their optimum levels. The choice of the titanium-precursor type is found to be the predominant factor affecting the efficiency of TiO 2 for hydrogen gas evolution. The interaction between precursor type and surfactant type is also statistically significant. The statistically optimized study identifies that combining F-108 amphiphilic block copolymers with titanium(III) chloride solution leads to TiO 2 exhibiting the highest photocatalytic efficiency for the generation of molecular hydrogen. The thus prepared TiO 2 shows relatively high photocatalytic hydrogen evolution rates (1.22 mmol h −1 g −1) compared to the commercially available TiO 2 photocatalysts which are not active for hydrogen generation in the absence of a co-catalyst. Significant photocatalytic reforming of ethanol is achieved over the synthesized bare TiO 2 with the formation of acetaldehyde as the main by-product in the gas phase. This unexpected photocatalytic performance is mainly attributed to the shift of flat band potential towards more negative potentials as revealed from the characterization results in addition to the high density of charge carriers exhibiting longer lifetime shown by laser transient reflectance measurements. The latter showed the presence of a high number of trapped states, which are beneficial for the photocatalytic properties.
Keywords
- Design of experiment, EISA, Molecular hydrogen evolution, Photocatalysis, TiO
ASJC Scopus subject areas
- Chemical Engineering(all)
- Catalysis
- Environmental Science(all)
- Chemical Engineering(all)
- Process Chemistry and Technology
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Applied Catalysis B: Environmental, Vol. 238, 15.12.2018, p. 422-433.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Co-catalyst-free photocatalytic hydrogen evolution on TiO2
T2 - Synthesis of optimized photocatalyst through statistical material science
AU - AlSalka, Yamen
AU - Hakki, Amer
AU - Schneider, Jenny
AU - Bahnemann, Detlef W.
N1 - Funding Information: The financial support from the Deutscher Akademischer Austauschdienst (DAAD) and the Federal Foreign Office is gratefully acknowledged. This Special Issue is dedicated to honor the retirement of Dr. John Kiwi at the Swiss Federal Institute of Technology (Lausanne), a key figure in the topic of photocatalytic materials for the degradation of contaminants of environmental concern.
PY - 2018/12/15
Y1 - 2018/12/15
N2 - An active TiO 2 for co-catalyst-free photocatalytic hydrogen evolution was successfully synthesized employing a simple Evaporation-Induced Self-Assembly (EISA) method that was developed and optimized with the help of Design of Experiment (DoE) coupled with Full Factorial Design (FFD) methodology. Coupling DoE with FFD provides a statistical tool for optimizing the synthesis process while carrying out the smallest number of experiments. This tool builds a statistical framework to determine the significance of the studied factors, i.e., titanium-precursor type, surfactant type and surfactant quantity, along with their potential interactions, as well as with their optimum levels. The choice of the titanium-precursor type is found to be the predominant factor affecting the efficiency of TiO 2 for hydrogen gas evolution. The interaction between precursor type and surfactant type is also statistically significant. The statistically optimized study identifies that combining F-108 amphiphilic block copolymers with titanium(III) chloride solution leads to TiO 2 exhibiting the highest photocatalytic efficiency for the generation of molecular hydrogen. The thus prepared TiO 2 shows relatively high photocatalytic hydrogen evolution rates (1.22 mmol h −1 g −1) compared to the commercially available TiO 2 photocatalysts which are not active for hydrogen generation in the absence of a co-catalyst. Significant photocatalytic reforming of ethanol is achieved over the synthesized bare TiO 2 with the formation of acetaldehyde as the main by-product in the gas phase. This unexpected photocatalytic performance is mainly attributed to the shift of flat band potential towards more negative potentials as revealed from the characterization results in addition to the high density of charge carriers exhibiting longer lifetime shown by laser transient reflectance measurements. The latter showed the presence of a high number of trapped states, which are beneficial for the photocatalytic properties.
AB - An active TiO 2 for co-catalyst-free photocatalytic hydrogen evolution was successfully synthesized employing a simple Evaporation-Induced Self-Assembly (EISA) method that was developed and optimized with the help of Design of Experiment (DoE) coupled with Full Factorial Design (FFD) methodology. Coupling DoE with FFD provides a statistical tool for optimizing the synthesis process while carrying out the smallest number of experiments. This tool builds a statistical framework to determine the significance of the studied factors, i.e., titanium-precursor type, surfactant type and surfactant quantity, along with their potential interactions, as well as with their optimum levels. The choice of the titanium-precursor type is found to be the predominant factor affecting the efficiency of TiO 2 for hydrogen gas evolution. The interaction between precursor type and surfactant type is also statistically significant. The statistically optimized study identifies that combining F-108 amphiphilic block copolymers with titanium(III) chloride solution leads to TiO 2 exhibiting the highest photocatalytic efficiency for the generation of molecular hydrogen. The thus prepared TiO 2 shows relatively high photocatalytic hydrogen evolution rates (1.22 mmol h −1 g −1) compared to the commercially available TiO 2 photocatalysts which are not active for hydrogen generation in the absence of a co-catalyst. Significant photocatalytic reforming of ethanol is achieved over the synthesized bare TiO 2 with the formation of acetaldehyde as the main by-product in the gas phase. This unexpected photocatalytic performance is mainly attributed to the shift of flat band potential towards more negative potentials as revealed from the characterization results in addition to the high density of charge carriers exhibiting longer lifetime shown by laser transient reflectance measurements. The latter showed the presence of a high number of trapped states, which are beneficial for the photocatalytic properties.
KW - Design of experiment
KW - EISA
KW - Molecular hydrogen evolution
KW - Photocatalysis
KW - TiO
UR - http://www.scopus.com/inward/record.url?scp=85050159425&partnerID=8YFLogxK
U2 - 10.1016/j.apcatb.2018.07.045
DO - 10.1016/j.apcatb.2018.07.045
M3 - Article
VL - 238
SP - 422
EP - 433
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
SN - 0926-3373
ER -