Browse
Submit Data
Databases
API
Help

Dataset Information

18 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Photocatalytic Overall Water Splitting by SrTiO₃ with Surface Oxygen Vacancies.

ABSTRACT: Strontium Titanate has a typical perovskite structure with advantages of low cost and photochemical stability. However, the wide bandgap and rapid recombination of electrons and holes limited its application in photocatalysis. In this work, a SrTiO₃ material with surface oxygen vacancies was synthesized via carbon reduction under a high temperature. It was successfully applied for photocatalytic overall water splitting to produce clean hydrogen energy under visible light irradiation without any sacrificial reagent for the first time. The photocatalytic overall water splitting ability of the as-prepared SrTiO₃-C950 is attributed to the surface oxygen vacancies that can make suitable energy levels for visible light response, improving the separation and transfer efficiency of photogenerated carriers.

SUBMITTER: Fan Y

PROVIDER: S-EPMC7767457 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Photocatalytic Overall Water Splitting by SrTiO3 with Surface Oxygen Vacancies.

Fan Yanfei Y Liu Yan Y Cui Hongyu H Wang Wen W Shang Qiaoyan Q Shi Xifeng X Cui Guanwei G Tang Bo B

Nanomaterials (Basel, Switzerland) 20201221 12

Strontium Titanate has a typical perovskite structure with advantages of low cost and photochemical stability. However, the wide bandgap and rapid recombination of electrons and holes limited its application in photocatalysis. In this work, a SrTiO3 material with surface oxygen vacancies was synthesized via carbon reduction under a high temperature. It was successfully applied for photocatalytic overall water splitting to produce clean hydrogen energy under visible light irradiation w ...[more]

PMID: 33371422

Similar Datasets

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

Project description: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 ?mol 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.

| S-EPMC7279556 | biostudies-literature

Photocatalytic overall water splitting by conjugated semiconductors with crystalline poly(triazine imide) frameworks.

Project description:Photocatalytic water splitting is an ideal pathway to produce hydrogen for the future energy supply due to the sustainability of solar energy and the mild reaction conditions. In the past four decades, many inorganic semiconductor photocatalysts have been studied for this purpose. In recent years, conjugated polymers, in particular covalent carbon nitride frameworks, have rapidly emerged as a new family of photocatalysts. However, the use of conjugated photocatalysts in overall water splitting in the absence of sacrificial agents has been much less reported. Herein, we used surface kinetic control to photocatalyze overall water splitting by a covalent carbon nitride semiconductor with a crystalline poly(triazine imide) (PTI) frameworks. Our study demonstrates that the loading of a Pt co-catalyst on the PTI surface plays the key role in inducing overall water splitting. The co-deposition of a cobalt species can effectively increase the photocatalytic activity and adjust the ratio of H2 and O2 produced, as well as enhancing the stability of the photocatalyst. The optimal sample with the dual co-catalysts shows an apparent quantum yield of 2.1% for the overall water splitting reaction.

| S-EPMC5613792 | biostudies-literature

A Ternary Dumbbell Structure with Spatially Separated Catalytic Sites for Photocatalytic Overall Water Splitting

Project description:Abstract Solar?driven overall water splitting based on metal sulfide semiconductor photocatalysts remains as a challenge owing to the strong charge recombination and deficient catalytic active sites. Additionally, significant inhibition of back reactions, especially the oxidation of sulfide ions during the photocatalytic water oxidation catalysis, is an arduous task that requires an efficient photogenerated hole transfer dynamics. Here, a ternary dumbbell?shaped catalyst based on RuO2/CdS/MoS2 with spatially separated catalytic sites is developed to achieve simultaneous production of hydrogen and oxygen under simulated solar?light without any sacrificial agents. Particularly, MoS2 nanosheets anchored on the two ends of CdS nanowires are identified as a reduction cocatalyst to accelerate hydrogen evolution, while RuO2 nanoparticles as an oxidation cocatalyst are deposited onto the sidewalls of CdS nanowires to facilitate oxygen evolution kinetics. The density functional theory simulations and ultrafast spectroscopic results reveal that photogenerated electrons and holes directionally migrate to MoS2 and RuO2 catalytic sites, respectively, thus achieving efficient charge carrier separation. The design of ternary dumbbell structure guarantees metal sulfides against photocorrosion and thus extends their range in solar water splitting. The ternary dumbbell?like RuO2/CdS/MoS2 photocatalyst with selective attachment of reduction and oxidation cocatalysts enables water splitting into H2 and O2. The critical aspect is the spatially separated distribution of MoS2 and RuO2 dual cocatalysts, which not only achieves photogenerated electron–hole pairs separation, but also protects CdS from photocorrosion by holes.

| S-EPMC7507026 | biostudies-literature

Insight into the Contributions of Surface Oxygen Vacancies on the Promoted Photocatalytic Property of Nanoceria.

Project description:Oxygen vacancies (OVs) have critical effects on the photoelectric characterizations and photocatalytic activity of nanoceria, but the contributions of surface OVs on the promoted photocatalytic properties are not clear yet. In this work, we synthesized ceria nanopolyhedron (P-CeO2), ceria nanocube (C-CeO2) and ceria nanorod (R-CeO2), respectively, and annealed them at 600 °C in air, 30%, 60% or pure H2. After annealing, the surface OVs concentration of ceria elevates with the rising of H2 concentration. Photocatalytic activity of annealed ceria is promoted with the increasing of surface OVs, the methylene blue photodegradation ratio with pure hydrogen annealed of P-CeO2, C-CeO2 or R-CeO2 is 93.82%, 85.15% and 90.09%, respectively. Band gap of annealed ceria expands first and then tends to narrow slightly with the rising of surface OVs, while the valence band (VB) and conductive band (CB) of annealed ceria changed slightly. Both of photoluminescence spectra and photocurrent results indicate that the separation efficiency of photoinduced electron-hole pairs is significantly enhanced with the increasing of the surface OVs concentration. The notable weakened recombination of photogenerated carrier is suggested to attribute a momentous contribution on the enhanced photocatalytic activity of ceria which contains surface OVs.

| S-EPMC8145243 | biostudies-literature

Photocatalytic Overall Water Splitting over MIL-125(Ti) upon CoPi and Pt Co-catalyst Deposition.

Project description:Photocatalytic overall water splitting is realized by taking advantage of the semiconductive and porous properties of MIL-125(Ti). CoPi and Pt are deposited into MIL-125(Ti) in two steps. The co-catalysts CoPi and Pt not only act as reactive sites for oxygen and hydrogen evolution, respectively, but also improve the photogenerated charge separation efficiency. The above conclusions are supported by the photoelectrical and photophysical results.

| S-EPMC5715264 | biostudies-literature

Role of Surface Oxygen Vacancies and Lanthanide Contraction Phenomenon of Ln(OH)3 (Ln = La, Pr, and Nd) in Sulfide-Mediated Photoelectrochemical Water Splitting.

Project description:Herein, we report the role of surface oxygen vacancies and lanthanide contraction phenomenon on HS- anion adsorption and desorption in the sulfide-mediated photoelectrochemical water splitting of Ln(OH)3 (Ln = La, Pr, and Nd). The Ln(OH)3 were synthesized via a solvothermal route using ethylenediamine as the solvent. The surface defects are characterized by Raman, X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), and high-resolution transmission electron microscopy analyses. The photoelectrochemical water-splitting behavior of Ln(OH)3 enriched with surface oxygen vacancies has been examined in a 1 M Na2S solution under illumination conditions. La(OH)3 exhibited a highly stable and saturated current density of ∼26 mA/cm2 at 0.8 V (vs Ag/AgCl). Similarly, the hydroxides of Pr and Nd demonstrated current densities of 18 and 14 mA/cm2, respectively, at 0.8 V (vs Ag/AgCl). A reduction trend in the saturated current densities from La to Nd indicates the lanthanide contraction phenomenon, where the basicity decreases in the same order. The results also demonstrate that the surface adsorption of the HS- anion in the active sites of the surface oxygen vacancies played a vital role in enhancing the photoelectrochemical water-splitting behavior of Ln(OH)3. The stability of Ln(OH)3 was examined after 4 h of chronoamperometry studies at 0.8 V (vs Ag/AgCl) and analyzed using X-ray diffraction, Fourier transform infrared, Raman, and EPR and XPS analyses. The results show that the Ln(OH)3 exhibited excellent stability by demonstrating their phase purity after photoelectrochemical water splitting. We propose Ln(OH)3 as highly stable photoelectrochemical water-splitting catalysts in highly concentrated sulfide-based electrolytes and anticipate Ln(OH)3 systems to be explored in a major scale for the production of H2 as an ecofriendly process.

| S-EPMC6644464 | biostudies-literature

A Cocrystal Precursor Strategy for Carbon-Rich Graphitic Carbon Nitride toward High-Efficiency Photocatalytic Overall Water Splitting.

Project description:Direct and efficient photocatalytic overall water splitting is crucial for the sustainable conversion and storage of renewable solar energy. Herein, we present the design of a carbon-rich graphitic carbon nitride (Cco-C3N4), prepared from a layered molecular cocrystal precursor. The cocrystal microsheets were synthesized using a facile hydrothermal process. Following two-step thermal treatment and liquid exfoliation, the product maintains the 2D morphology owing to the toptactic transformation process. The Cco-C3N4 exhibits an enhanced photogenerated electron-hole separation, high charge transport capacity, and prolonged lifetime of the carriers, relative to the g-C3N4 system. In the absence of any sacrificial reagent or co-catalyst, the Cco-C3N4 microsheets exhibit a high photocatalytic activity. The work presented in this report supplies a cocrystal route for the orderly molecular self-assembly of precursor materials to tailor the chemical compositions and electronic structures. Moreover, the generation of a highly efficient water-splitting photocatalyst has larger implications for sustainable energy applications.

| S-EPMC6542374 | biostudies-literature

Photogenerated Oxygen Vacancies in Hierarchical Ag/TiO2 Nanoflowers for Enhanced Photocatalytic Reactions.

Project description:Oxygen vacancy (Vo) creation and morphology controlling make significant contributions to the electronic and structural regulation of metal oxide semiconductors, yet an investigation about convenient approaches for fabricating hierarchical catalyst with abundant oxygen vacancies still has significant challenges. Here, we report a unique method to create abundant oxygen vacancies in hierarchical Ag/TiO2 nanoflowers during photocatalytic reaction, which is accompanied by light absorption variation and surface plasmon resonance (SPR) enhancement. Its high efficiency of photocatalytic H2 evolution (the highest apparent quantum yield reaches 3.2% at 365 nm) and rhodamine B degradation can be considered as benefits from the synergistic effects of the well-arranged hierarchical structure, the photogenerated oxygen vacancies, and the SPR of cocatalyst Ag. This work proposes an effective strategy to optimize the synthesis of regular hierarchical structures and enriches the research on the vital function of oxygen vacancies in photocatalytic reactions.

| S-EPMC7301581 | biostudies-literature

Ultrathin CdSe in Plasmonic Nanogaps for Enhanced Photocatalytic Water Splitting.

Project description:Enhanced plasmonic fields are a promising way to increase the efficiency of photocatalytic water splitting. The availability of atomically thin materials opens up completely new opportunities. We report photocatalytic water splitting on ultrathin CdSe nanoplatelets placed in plasmonic nanogaps formed by a flat gold surface and a gold nanoparticle. The extreme field intensity created in these gaps increases the electron–hole pair production in the CdSe nanoplatelets and enhances the plasmon-mediated interfacial electron transfer. Compared to individual nanoparticles commonly used to enhance photocatalytic processes, gap-plasmons produce several orders of magnitude higher field enhancement, strongly localized inside the semiconductor sheet thus utilizing the entire photocatalyst efficiently.

| S-EPMC4415030 | biostudies-literature

Laser Synthesis of Iridium Nanospheres for Overall Water Splitting.

Project description:Engineering surface structure of catalysts is an efficient way towards high catalytic performance. Here, we report on the synthesis of regular iridium nanospheres (Ir NSs), with abundant atomic steps prepared by a laser ablation technique. Atomic steps, consisting of one-atom level covering the surface of such Ir NSs, were observed by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The prepared Ir NSs exhibited remarkably enhanced activity both for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in acidic medium. As a bifunctional catalyst for overall water splitting, they achieved a cell voltage of 1.535 V @ 10 mA/cm2, which is much lower than that of Pt/C-Ir/C couple (1.630 V @ 10 mA/cm2).

| S-EPMC6766323 | biostudies-literature