scholarly journals Nanoscale Multidimensional Pd/TiO2/g-C3N4 Catalyst for Efficient Solar-Driven Photocatalytic Hydrogen Production

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 59
Author(s):  
Ting-Han Lin ◽  
Yin-Hsuan Chang ◽  
Kuo-Ping Chiang ◽  
Jer-Chyi Wang ◽  
Ming-Chung Wu
Keyword(s):  
Hydrogen Production ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Visible Region ◽  
Green Energy ◽  
Solar Irradiation ◽  
Xenon Lamp ◽  
Tio2 Nanofibers ◽  
Photocatalytic Hydrogen Production

Solar-to-fuel conversion is an innovative concept for green energy, attracting many researchers to explore them. Solar-driven photocatalysts have become an essential solution to provide valuable chemicals like hydrogen, hydrocarbon, and ammonia. For sustainable stability under solar irradiation, titanium dioxide is regarded as an acceptable candidate, further showing excellent photocatalytic activity. Incorporating the photo-sensitizers, including noble metal nanoparticles and polymeric carbon-based material, can improve its photoresponse and facilitate the electron transfer and collection. In this study, we synthesized the graphitic carbon nitride (g-C3N4) nanosheet incorporated with high crystalline TiO2 nanofibers (NF) as 1D/2D heterostructure catalyst for photocatalytic water splitting. The microstructure, optical absorption, crystal structure, charge carrier dynamics, and specific surface area were characterized systematically. The low bandgap of 2D g-C3N4 nanosheets (NS) as a sensitizer improves the specific surface area and photo-response in the visible region as the incorporated amount increases. Because of the band structure difference between TiO2 and g-C3N4, constructing the heterojunction formation, the superior separation of electron-hole is observed. The detection of reactive oxygen species and photo-assisted Kelvin probe microscopy are conducted to investigates the possible charge migration. The highest photocatalytic hydrogen production rate of Pd/TiO2/g-C3N4 achieves 11.62 mmol·h−1·g−1 under xenon lamp irradiation.

High Specific Surface Area TiO2 Nanospheres for Hydrogen Production and Photocatalytic Activity

2020 ◽  
Vol 20 (5) ◽  
pp. 3217-3224 ◽  
Author(s):  
Dong Huang ◽  
Haixia Liu ◽  
Junwei Bian ◽  
Tianduo Li ◽  
Baibiao Huang ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Production Efficiency ◽  
Carbon Chain ◽  
High Specific Surface Area ◽  
Energy Utilization ◽  
Capping Agent ◽  
Good Crystallinity

TiO2 nanospheres with high specific surface area and good crystallinity were prepared by a hydrothermal method using urea as the capping agent and isopropanol as the solvent. The capping agent effectively controlled the morphology of TiO2 nanospheres and led to improved crystallinity. Using a solvent with a long carbon chain, such as isopropanol, also promoted the formation of TiO2 nanospheres. TiO2 nanospheres with different morphologies were prepared by adjusting the amount of urea. It was found that when TiO2-0.6 was used as the photocatalyst, highest rates of degradation of both methylene blue and rhodamine B under ultraviolet-visible light were observed. Moreover TiO2-0.6 also had the largest hydrogen production efficiency among the different TiO2 samples tested. Thus, TiO2 nanospheres have great development potential and application prospects in environmental management and new modes of energy utilization.

scholarly journals Simultaneous deposition of Au nanoparticles during flame synthesis of TiO2 and SiO2

2003 ◽  
Vol 18 (1) ◽  
pp. 115-120 ◽  
Author(s):  
L. Mädler ◽  
W. J. Stark ◽  
S. E. Pratsinis
Keyword(s):  
Metal Oxide ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Au Nanoparticles ◽  
Visible Region ◽  
Gold Deposits ◽  
Absorption Bands ◽  
Oxide Support ◽  
Metal Oxide Support

Nanostructured gold/titania and gold/silica particles with up to 4 wt% Au were made by a single-step process in a spray flame reactor. Gold(III)-chloride hydrate and titania- or silica-based metalorganic precursors were mixed in a liquid fuel solution, keeping concentrations in the flame and overall combustion enthalpy constant. The powders were characterized by x-ray diffraction, transmission electron microscopy, Brunauer–Emmett–Teller, and ultraviolet–visible analysis. The titania or silica specific surface area and the crystalline structure of titania were not affected by the presence of gold in the flame. Furthermore the size of the gold deposits was independent of the metal oxide support (TiO2 or SiO2) and its specific surface area (100 and 320 m2/g, respectively). The gold nanoparticles were nonagglomerated, spherical, mostly single crystalline, and well dispersed on the metal oxide support. Depending on the Au weight fraction (1, 2, and 4 wt%) the Au nanoparticles' mass mean diameter was 3, 7, and 15 nm, respectively, on both titania and silica. The particles showed surface plasmon absorption bands in the ultraviolet–visible region, which is typical for nano-sized gold. This absorption band was red shifted in the case of the titania support, while no shift occurred with the silica support.

Highly Efficient Photodegradation of MO Dye by TiO2 Nanoparticles

2014 ◽  
Vol 989-994 ◽  
pp. 527-530
Author(s):  
Xin Zuo Fang ◽  
Li Sheng Gao
Keyword(s):  
Crystal Structure ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Small Diameter ◽  
Solar Irradiation ◽  
Solar Light ◽  
Thermal Method ◽  
Highly Efficient ◽  
Good Dispersion

use the sol-thermal method to synthesis nanoparticle TiO2 which is well developed, small diameter and good dispersion. XRD and BET methods were used to analyze the crystal structure and specific surface area. Under nature solar light, the photodegradation activity of TiO2is tested. The results show that the TiO2sample displayed better photodegradation activity than P25 under solar irradiation.

scholarly journals Hierarchical amorphous nanofibers for transparent inherently super-hydrophilic coatings

2014 ◽  
Vol 2 (37) ◽  
pp. 15575-15581 ◽  
Author(s):  
William S. Y. Wong ◽  
Noushin Nasiri ◽  
Alexandra L. Rodriguez ◽  
David R. Nisbet ◽  
Antonio Tricoli
Keyword(s):  
Specific Surface ◽  
Surface Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
Tio2 Nanofibers ◽  
Amorphous Tio2 ◽  
Hydrophilic Coatings

Inherent super-hydrophilic coatings, not requiring UV-activation, were synthesized by optimal electrospinning of amorphous TiO2 nanofibers with ultra-high specific surface area. Their mesoporous surface structure led to enhanced wettability and excellent anti-fogging properties that were preserved even up to three days of storage in darkness.

scholarly journals Structural, photocatalytic and surface analysis of Nb/Ag codoped TiO2 mesoporous nanoparticles

2020 ◽  
Vol 96 (3) ◽  
pp. 728-741
Author(s):  
Mahtab Gorgani ◽  
Behzad Koozegar Kaleji
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Band Gap Energy ◽  
Xenon Lamp ◽  
X Ray ◽  
Mesoporous Nanoparticles

Abstract In this study, several TiO2 mesoporous nanoparticles with different mol% of niobium and silver were synthesized using the sol–gel method. The crystalline phase, chemical state, photocatalytic and optical properties, specific surface area, and morphology of mesoporous nanoparticles were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–Vis reflective spectroscopy (UV–Vis), Brunauer–Emmett–Teller-specific surface area (BET) and field emission scanning electron microscopy (FESEM). With increasing calcination temperature, the photocatalytic activity of the samples gradually increased due to the improvement of crystallization of the anatase and rutile phases. Nb/Ag codoping sample calcined at 550 °C has reduced the band gap energy (3.17 eV to 3.06 eV) and improved the photocatalytic properties of samples under visible light (xenon lamp, 200 W for 1 h and 2 h). Doped TiO2 mesoporous nanoparticles were shown to have the highest photocatalytic activity as compared with the pure TiO2 nanoparticles. The best photocatalytic efficiency of codoped TiO2 mesoporous nanoparticles was observed for the TNA3 sample calcined under 550 °C, containing molar contents of Nb (0.5 mol%) and Ag (1 mol%) dopant ions with 95.60% efficiency.

scholarly journals Characterization and photocatalytic activity of ZnO nanoflowers synthesized using Bridelia retusa leaf extract

2021 ◽  
Author(s):  
Ramesh Vinayagam ◽  
Shraddha Pai ◽  
Thivaharan Varadavenkatesan ◽  
Arivalagan Pugazhendhi ◽  
Raja Selvaraj
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Leaf Extract ◽  
Solar Irradiation ◽  
Bandgap Energy ◽  
Absorption Bands ◽  
First Order Kinetics ◽  
Bet Analysis ◽  
Bridelia Retusa

AbstractIn the current work, the leaf extract of Bridelia retusa was used for the first time to synthesize zinc oxide nanoparticles (ZnONPs). A zinc nanoparticle-specific 364-nm peak was discerned via UV–Vis studies with a typical bandgap energy of 3.41 eV. FE-SEM micrographs revealed flower-shaped structure of the ZnONPs. EDS analysis corroborated the presence of zinc and oxygen. XRD spectrum established the wurtzite structure, sized at 11.06 nm. The mesoporous texture (4.89 nm) of the nanoparticles was deduced from BET analysis, proving a higher specific surface area than commercial ZnONPs. FTIR spectroscopy resulted in absorption bands typical for ZnONPs. Within a span of 165 min, under solar irradiation, the ZnONPs facilitated the photocatalytic degradation of Rhodamine B dye upto 94.74%. Exhibiting pseudo-first-order kinetics, the process had a degradation constant of 0.0109 min−1. It was concluded that numerous factors led to the high degradation efficiency. High values of bandgap energy and specific surface area, along with the mesoporous and crystalline nature of the ZnONPs led to the observed effect. The ZnONPs were also stabilized by the phytochemicals in the B. retusa leaves. The study is thus able to successfully demonstrate the huge potential in the field of environmental nanoremediation. The viability of using ZnONPs as solar photocatalysts for treating dye-laden industrial wastewater was thus attested.

scholarly journals Synthesis and Characterization of Mn–C–CodopedTiO2Nanoparticles and Photocatalytic Degradation of Methyl Orange Dye under Sunlight Irradiation

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Wei Xin ◽  
Duanwei Zhu ◽  
Guanglong Liu ◽  
Yumei Hua ◽  
Wenbing Zhou
Keyword(s):  
Particle Size ◽  
Methyl Orange ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Visible Region ◽  
High Specific Surface Area ◽  
Size Analysis ◽  
Manganese Acetate ◽  
Sunlight Irradiation

Novel visible-light-active Mn–C–TiO2nanoparticles were synthesized by modified sol-gel method based on the self-assembly technique using polyoxyethylenes orbitan monooleate (Tween 80) as template and carbon precursor and manganese acetate as manganese precursor. The samples were characterized by XRD, FTIR, UV-vis diffuse reflectance, XPS, and laser particle size analysis. The XRD results showed that Mn–C–TiO2sample exhibited anatase phase and no other crystal phase was identified. High specific surface area, small crystallite size, and small particle size distribution could be obtained by manganese and carbon codoped and Mn–C–TiO2exhibited greater red shift in absorption edge of samples in visible region than that of C–TiO2and pure TiO2. The photocatalytic activity of synthesized catalyst was evaluated by photocatalytic oxidation of methyl orange (MO) solution under the sunlight irradiation. The results showed that Mn–C–TiO2nanoparticles have higher activity than other samples under sunlight, which could be attributed to the high specific surface area, smaller particle size, and lower band gap energy.

scholarly journals Fe-Doped g-C3N4: High-Performance Photocatalysts in Rhodamine B Decomposition

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1963
Author(s):  
Minh Nguyen Van ◽  
Oanh Mai ◽  
Chung Pham Do ◽  
Hang Lam Thi ◽  
Cuong Pham Manh ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Recombination Rate ◽  
High Performance ◽  
Area Measurement ◽  
Bet Surface Area ◽  
Xenon Lamp ◽  
Electron Hole ◽  
X Ray

Herein, Fe-doped C3N4 high-performance photocatalysts, synthesized by a facile and cost effective heat stirring method, were investigated systematically using powder X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) surface area measurement, X-ray photoelectron (XPS), UV–Vis diffusion reflectance (DRS) and photoluminescence (PL) spectroscopy. The results showed that Fe ions incorporated into a g-C3N4 nanosheet in both +3 and +2 oxidation states and in interstitial configuration. Absorption edge shifted slightly toward the red light along with an increase of absorbance in the wavelength range of 430–570 nm. Specific surface area increased with the incorporation of Fe into g-C3N4 lattice, reaching the highest value at the sample doped with 7 mol% Fe (FeCN7). A sharp decrease in PL intensity with increasing Fe content is an indirect evidence showing that electron-hole pair recombination rate decreased. Interestingly, Fe-doped g-C3N4 nanosheets present a superior photocatalytic activity compared to pure g-C3N4 in decomposing RhB solution. FeCN7 sample exhibits the highest photocatalytic efficiency, decomposing almost completely RhB 10 ppm solution after 30 min of xenon lamp illumination with a reaction rate approximately ten times greater than that of pure g-C3N4 nanosheet. This is in an agreement with the BET measurement and photoluminescence result which shows that FeCN7 possesses the largest specific surface area and low electron-hole recombination rate. The mechanism of photocatalytic enhancement is mainly explained through the charge transfer processes related to Fe2+/Fe3+ impurity in g-C3N4 crystal lattice.

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