scholarly journals Fabrication of ILs-Assisted AgTaO3 Nanoparticles for the Water Splitting Reaction: The Effect of ILs on Morphology and Photoactivity

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4055
Author(s):  
Julia Zwara ◽  
Anna Pancielejko ◽  
Marta Paszkiewicz-Gawron ◽  
Justyna Łuczak ◽  
Magdalena Miodyńska ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Ionic Liquids ◽  
Solid State ◽  
Water Splitting ◽  
Hydrogen Generation ◽  
Sol Gel ◽  
Pt Nanoparticles ◽  
H2 Production ◽  
Solid State Reactions ◽  
Platinum Particles

The design of an active, stable and efficient photocatalyst that is able to be used for hydrogen production is of great interest nowadays. Therefore, four methods of AgTaO3 perovskite synthesis, such as hydrothermal, solvothermal, sol-gel and solid state reactions, were proposed in this study to identify the one with the highest hydrogen generation efficiency by the water splitting reaction. The comprehensive results clearly show that the solid state reaction (SSR) led to the obtainment of a sample with an almost seven times higher photocatalytic activity than the other methods. Furthermore, four ionic liquids, all possessing nitrogen in the form of organic cations (two imidazoliums with different anions, ammonium and tetrazolium), were used for the first time to prepare composites consisting of AgTaO3 modified with IL and Pt, simultaneously. The effect of the ionic liquids (ILs) and Pt nanoparticles’ presence on the structure, morphology, optical properties, elemental composition and the effectiveness of the hydrogen generation was investigated and discussed. The morphology investigation revealed that the AgTaO3 photocatalysts with the application of [OMIM]-cation based ILs created smaller granules (<500 nm), whereas [TBA] [Cl] and [TPTZ] [Cl] ILs caused the formation of larger particles (up to 2 μm). We found that various ILs used for the synthesis did not improve the photocatalytic activity of the obtained samples in comparison with pristine AgTaO3. It was detected that the compound with the highest ability for hydrogen generation under UV-Vis irradiation was the AgTaO3_0.2% Pt (248.5 μmol∙g−1), having an almost 13 times higher efficiency in comparison with the non-modified pristine sample. It is evidenced that the enhanced photocatalytic activity of modified composites originated mainly from the presence of the platinum particles. The mechanism of photocatalytic H2 production under UV-Vis light irradiation in the presence of an AgTaO3_IL_Pt composite in the water splitting reaction was also proposed.

The use of high-resolution FESEM to study solid-state phase transformations and reactions

1994 ◽  
Vol 52 ◽  
pp. 1028-1029
Author(s):  
P. G. Kotula ◽  
D. D. Erickson ◽  
C. B. Carter
Keyword(s):  
Solid State ◽  
High Resolution ◽  
Phase Transformations ◽  
High Efficiency ◽  
Sol Gel ◽  
Quantitative Information ◽  
Solid State Reactions ◽  
Critical Dimensions ◽  
Backscattered Electrons ◽  
Backscattered Electron

High-resolution field-emission-gun scanning electron microscopy (FESEM) has recently emerged as an extremely powerful method for characterizing the micro- or nanostructure of materials. The development of high efficiency backscattered-electron detectors has increased the resolution attainable with backscattered-electrons to almost that attainable with secondary-electrons. This increased resolution allows backscattered-electron imaging to be utilized to study materials once possible only by TEM. In addition to providing quantitative information, such as critical dimensions, SEM is more statistically representative. That is, the amount of material that can be sampled with SEM for a given measurement is many orders of magnitude greater than that with TEM.In the present work, a Hitachi S-900 FESEM (operating at 5kV) equipped with a high-resolution backscattered electron detector, has been used to study the α-Fe2O3 enhanced or seeded solid-state phase transformations of sol-gel alumina and solid-state reactions in the NiO/α-Al2O3 system. In both cases, a thin-film cross-section approach has been developed to facilitate the investigation. Specifically, the FESEM allows transformed- or reaction-layer thicknesses along interfaces that are millimeters in length to be measured with a resolution of better than 10nm.

Photocatalytic Water Splitting and Photocatalytic Degradation in Aqueous GdVO4 Suspensions under Simulated Solar Irradiation

2013 ◽  
Vol 873 ◽  
pp. 571-574 ◽  
Author(s):  
Yan Bai ◽  
Ya Ming Ding ◽  
Zhi Min Li
Keyword(s):  
Photocatalytic Activity ◽  
High Temperature ◽  
Solid State ◽  
Water Splitting ◽  
Rhodamine B ◽  
Pure Water ◽  
Xrd Analysis ◽  
Solar Irradiation ◽  
Tetragonal Type ◽  
Simulated Solar Irradiation

GdVO4 was synthesized by solid state reaction at high temperature and characterized by XRD, UVvisible DRS, BET and SEM. XRD analysis of GdVO4 showed its structure was of tetragonal type. When GdVO4 was loaded with 0.3 wt% Pt, it showed the better photocatalytic activity for water splitting under simulated solar irradiation, and the amounts of the produced hydrogen in pure water were about 9.33 μmol under the irradiation of simulated solar for 6 h. Furthermore, photodegradation of Rhodamine B (Rh B ) on the samples were investigated under simulated solar irradiation.

Photocatalytic activity of CaTiO3 synthesized by solid state, sol–gel and hydrothermal methods

2016 ◽  
Vol 81 (3) ◽  
pp. 806-813 ◽  
Author(s):  
Chong Han ◽  
Jingjing Liu ◽  
Wangjin Yang ◽  
Qianqian Wu ◽  
He Yang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Solid State ◽  
Sol Gel ◽  
Hydrothermal Methods

scholarly journals Vapor-Phase Photocatalytic Overall Water Splitting Using Hybrid Methylammonium Copper and Lead Perovskites

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 960 ◽  
Author(s):  
Teresa García ◽  
Rocío García-Aboal ◽  
Josep Albero ◽  
Pedro Atienzar ◽  
Hermenegildo García
Keyword(s):  
Photocatalytic Activity ◽  
Water Splitting ◽  
Vapor Phase ◽  
Irradiation Time ◽  
H2 Production ◽  
Charge Migration ◽  
Copper Halide ◽  
Overall Water Splitting ◽  
Sacrificial Agent ◽  
Maximum Production Rate

Films or powders of hybrid methylammonium copper halide perovskite exhibit photocatalytic activity for overall water splitting in the vapor phase in the absence of any sacrificial agent, resulting in the generation of H2 and O2, reaching a maximum production rate of 6 μmol H2 × g cat−1h−1 efficiency. The photocatalytic activity depends on the composition, degreasing all inorganic Cs2CuCl2Br2 perovskite and other Cl/Br proportions in the methylammonium hybrids. XRD indicates that MA2CuCl2Br2 is stable under irradiation conditions in agreement with the linear H2 production with the irradiation time. Similar to copper analogue, hybrid methylammonium lead halide perovskites also promote the overall photocatalytic water splitting, but with four times less efficiency than the Cu analogues. The present results show that, although moisture is strongly detrimental to the photovoltaic applications of hybrid perovskites, it is still possible to use these materials as photocatalysts for processes requiring moisture due to the lack of relevance in the photocatalytic processes of interparticle charge migration.

The sol–gel synthesis of perovskites by an EDTA/citrate complexing method involves nanoscale solid state reactions

2008 ◽  
Vol 10 (6) ◽  
pp. 689-701 ◽  
Author(s):  
A. Feldhoff ◽  
M. Arnold ◽  
J. Martynczuk ◽  
Th.M. Gesing ◽  
H. Wang
Keyword(s):  
Solid State ◽  
Sol Gel ◽  
Solid State Reactions ◽  
Sol Gel Synthesis

scholarly journals Exploration and evaluation of proton source-assisted photocatalyst for hydrogen generation

2019 ◽  
Vol 18 (7) ◽  
pp. 1716-1726 ◽  
Author(s):  
T. C. Bhagya ◽  
Athira Krishnan ◽  
Arunima Rajan S ◽  
Ameen Sha M ◽  
B. R. Sreelekshmy ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Water Splitting ◽  
Hydrogen Generation ◽  
Proton Source

The DAH proton source assisted Fe2O3–TiO2 system exhibits exceptional photocatalytic activity and stability for hydrogen generation by a water-splitting reaction.

Sol-gel prepared InTaO4 and its photocatalytic characteristics

2008 ◽  
Vol 23 (5) ◽  
pp. 1364-1370 ◽  
Author(s):  
Hsiang-Chen Chen ◽  
Hung-Chi Chou ◽  
Jeffrey C.S. Wu ◽  
Hsin-Yu Lin
Keyword(s):  
Thin Film ◽  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Solid State ◽  
Visible Light ◽  
Sol Gel ◽  
Thermal Hydrolysis ◽  
Visible Light Photocatalyst ◽  
First Time ◽  
State Fusion

InTaO4 is an efficient visible-light photocatalyst, which used to be synthesized by solid-state fusion at over 1100 °C. However, irregular morphology and severe agglomeration of particles were acquired due to nonuniform fusion of solid precursors. In this study, InTaO4 was synthesized by two sol-gel routes, the thermal hydrolysis and esterification methods. The precursors were indium (III) nitrate pentahydrate [In(NO3)3] and tantalum(V) butoxide [Ta(OC4H9)5] dissolved in solutions. The InTaO4 powders with a uniform grain size of 17.7 nm were successfully synthesized using the esterification method at a calcination temperature of 950 °C. A uniform InTaO4 thin film nearly 40 nm thick formed on an optical fiber at 1100 °C using the sol prepared by the esterification method. For the first time, InTaO4 was evaluated by the photocatalytic activity of CO2 photo reduction, which was conducted in aqueous solution under visible light irradiation. Cocatalyst NiO was loaded on the surface of InTaO4 to further enhance the methanol yield. The methanol yields of NiO/InTaO4 by esterification method were significantly higher than those by solid-state fusion. The esterification method provided homogeneous mixing of Ta(OC4H9)5 and In(NO3)3, resulting in nano-sized InTaO4 with uniform crystallinity and superior photocatalytic activity.

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