Microwave synthesis of a CoSe2/graphene–TiO2 heterostructure for improved hydrogen evolution from aqueous solutions in the presence of sacrificial agents

RSC Advances ◽  
2015 ◽  
Vol 5 (24) ◽  
pp. 18841-18849 ◽  
Author(s):  
Kefayat Ullah ◽  
Zhu Lei ◽  
Shu Ye ◽  
Asghar Ali ◽  
Won-Chun Oh
Keyword(s):  
Aqueous Solutions ◽  
Hydrogen Evolution ◽  
Microwave Synthesis ◽  
High Performance ◽  
Heterogeneous Material ◽  
Microwave Assisted ◽  
Tube Type

A heterogeneous material consisting of a tube type TiO2 was grown in the presence of a CoSe2/graphene hybrid, as a high-performance photocatalyst material, through a fast microwave-assisted technique.

Synthesis of hierarchical MoSe2 nanolayers on sodium sulfide crystals for electrocatalytic hydrogen evolution

CrystEngComm ◽  
2021 ◽  
Author(s):  
Xiaoshuang Chen ◽  
Meina Ju ◽  
Kun Song ◽  
Guoli Chen ◽  
Rui Yang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Evolution ◽  
High Performance ◽  
Sodium Sulfide ◽  
Hydrogen Generation ◽  
Clean Energy

Hydrogen generation via water electroreduction is a pivotal portion of exploiting clean-energy skills. Nevertheless, developing a low price and high-performance catalytic activity substance to take the place of expensively precious...

Modification of Ni3N with a Cobalt-Doped Carbon Shell for High-Performance Hydrogen Evolution in Alkaline Media

2021 ◽  
Vol 9 (5) ◽  
pp. 1994-2002
Author(s):  
Jie Sun ◽  
Jianmin Lu ◽  
Cunping Huang ◽  
Qiang Wu ◽  
Ligang Xia ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
High Performance ◽  
Carbon Shell ◽  
Alkaline Media

Flower-like tungsten-doped Fe–Co phosphides as efficient electrocatalysts for hydrogen evolution reaction

CrystEngComm ◽  
2021 ◽  
Author(s):  
Qian Zhang ◽  
Shuihua Tang ◽  
Lieha Shen ◽  
Weixiang Yang ◽  
Zhen Tang ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Adsorption Energy ◽  
High Performance ◽  
Hydrogen Adsorption ◽  
Cost Effective

Developing cost-effective and high-performance electrocatalysts for hydrogen evolution reaction (HER) are imperative thanks to rapid increase of fuel-cell driven vehicles. Tungsten (W) possesses advantages of optimized hydrogen adsorption energy and...

scholarly journals SnS2/TiO2 Nanocomposites for Hydrogen Production and Photodegradation Under Extended Solar Irradiation

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 589
Author(s):  
Sivagowri Shanmugaratnam ◽  
Balaranjan Selvaratnam ◽  
Aravind Baride ◽  
Ranjit Koodali ◽  
Punniamoorthy Ravirajan ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Hydrogen Evolution ◽  
Environmental Remediation ◽  
High Performance ◽  
Degradation Mechanism ◽  
Solar Irradiation ◽  
Earth Abundant ◽  
Improved Performance ◽  
Chalcogenide Materials

Earth–abundant transition metal chalcogenide materials are of great research interest for energy production and environmental remediation, as they exhibit better photocatalytic activity due to their suitable electronic and optical properties. This study focuses on the photocatalytic activity of flower-like SnS2 nanoparticles (composed of nanosheet subunits) embedded in TiO2 synthesized by a facile hydrothermal method. The materials were characterized using different techniques, and their photocatalytic activity was assessed for hydrogen evolution reaction and the degradation of methylene blue. Among the catalysts studied, 10 wt. % of SnS2 loaded TiO2 nanocomposite shows an optimum hydrogen evolution rate of 195.55 µmolg−1, whereas 15 wt. % loading of SnS2 on TiO2 exhibits better performance against the degradation of methylene blue (MB) with the rate constant of 4.415 × 10−4 s−1 under solar simulated irradiation. The improved performance of these materials can be attributed to the effective photo-induced charge transfer and reduced recombination, which make these nanocomposite materials promising candidates for the development of high-performance next-generation photocatalyst materials. Further, scavenging experiments were carried out to confirm the reactive oxygen species (ROS) involved in the photocatalytic degradation. It can be observed that there was a 78% reduction in the rate of degradation when IPA was used as the scavenger, whereas around 95% reduction was attained while N2 was used as the scavenger. Notably, very low degradation (<5%) was attained when the dye alone was directly under solar irradiation. These results further validate that the •OH radical and the superoxide radicals can be acknowledged for the degradation mechanism of MB, and the enhancement of degradation efficiency may be due to the combined effect of in situ dye sensitization during the catalysis and the impregnation of low bandgap materials on TiO2.

HPLC Analysis of Oxytetracycline Residues in Honey

1986 ◽  
Vol 49 (5) ◽  
pp. 383-388 ◽  
Author(s):  
PETER SPORNS ◽  
SUET KWAN ◽  
LAWRENCE A. ROTH
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Aqueous Solutions ◽  
High Performance ◽  
Hplc Analysis ◽  
Extraction Procedure ◽  
Hplc Method ◽  
Limits Of Detection ◽  
Ph Values ◽  
Double Extraction

Oxytetracycline (OTC), also known commercially as Terramycin, was determined to be more stable in honey than in buffered aqueous solutions at similar pH values and temperatures. A rapid high performance liquid chromatography (HPLC) method was developed to detect and quantitate OTC using a 1:1 dilution (wt/wt) of honey samples in water. Using 355 nm as the wavelength of detection, amounts as low as 0.5 μg/ml could be detected in the above solution. The limits of detection were lowered considerably by a double extraction procedure.

scholarly journals High-Performance Resistive Switching in Solution-Derived IGZO:N Memristors by Microwave-Assisted Nitridation

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1081
Author(s):  
Shin-Yi Min ◽  
Won-Ju Cho
Keyword(s):  
Resistive Switching ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Electric Pulse ◽  
Chemical Species ◽  
Optical Absorption Coefficient ◽  
Microwave Assisted ◽  
Synthesis Strategy ◽  
Metal Insulator Metal ◽  
Switching Characteristics

In this study, we implemented a high-performance two-terminal memristor device with a metal/insulator/metal (MIM) structure using a solution-derived In-Ga-Zn-Oxide (IGZO)-based nanocomposite as a resistive switching (RS) layer. In order to secure stable memristive switching characteristics, IGZO:N nanocomposites were synthesized through the microwave-assisted nitridation of solution-derived IGZO thin films, and the resulting improvement in synaptic characteristics was systematically evaluated. The microwave-assisted nitridation of solution-derived IGZO films was clearly demonstrated by chemical etching, optical absorption coefficient analysis, and X-ray photoelectron spectroscopy. Two types of memristor devices were prepared using an IGZO or an IGZO:N nanocomposite film as an RS layer. As a result, the IGZO:N memristors showed excellent endurance and resistance distribution in the 103 repeated cycling tests, while the IGZO memristors showed poor characteristics. Furthermore, in terms of electrical synaptic operation, the IGZO:N memristors possessed a highly stable nonvolatile multi-level resistance controllability and yielded better electric pulse-induced conductance modulation in 5 × 102 stimulation pulses. These findings demonstrate that the microwave annealing process is an effective synthesis strategy for the incorporation of chemical species into the nanocomposite framework, and that the microwave-assisted nitridation improves the memristive switching characteristics in the oxide-based RS layer.

scholarly journals Microwave-Assisted vs. Conventional Hydrothermal Synthesis of MoS2 Nanosheets: Application towards Hydrogen Evolution Reaction

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1040 ◽  
Author(s):  
Getachew Solomon ◽  
Raffaello Mazzaro ◽  
Vittorio Morandi ◽  
Isabella Concina ◽  
Alberto Vomiero
Keyword(s):  
Hydrothermal Synthesis ◽  
Hydrothermal Method ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Current Density ◽  
Crystal Morphology ◽  
Synthesis Method ◽  
Synthesis Methods ◽  
Mos2 Nanosheets ◽  
Microwave Assisted

Molybdenum sulfide (MoS2) has emerged as a promising catalyst for hydrogen evolution applications. The synthesis method mainly employed is a conventional hydrothermal method. This method requires a longer time compared to other methods such as microwave synthesis methods. There is a lack of comparison of the two synthesis methods in terms of crystal morphology and its electrochemical activities. In this work, MoS2 nanosheets are synthesized using both hydrothermal (HT-MoS2) and advanced microwave methods (MW-MoS2), their crystal morphology, and catalytical efficiency towards hydrogen evolution reaction (HER) were compared. MoS2 nanosheet is obtained using microwave-assisted synthesis in a very short time (30 min) compared to the 24 h hydrothermal synthesis method. Both methods produce thin and aggregated nanosheets. However, the nanosheets synthesized by the microwave method have a less crumpled structure and smoother edges compared to the hydrothermal method. The as-prepared nanosheets are tested and used as a catalyst for hydrogen evolution results in nearly similar electrocatalytic performance. Experimental results showed that: HT-MoS2 displays a current density of 10 mA/cm2 at overpotential (−280 mV) compared to MW-MoS2 which requires −320 mV to produce a similar current density, suggesting that the HT-MoS2 more active towards hydrogen evolutions reaction.

Graphene-Supported Pyrene-Modified Cobalt Corrole with Axial Triphenylphosphine for Enhanced Hydrogen Evolution in pH 0-14 Aqueous Solutions

ChemSusChem ◽  
2017 ◽  
Vol 10 (22) ◽  
pp. 4632-4641 ◽  
Author(s):  
Xialiang Li ◽  
Haitao Lei ◽  
Xiaojun Guo ◽  
Xueli Zhao ◽  
Shuping Ding ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Hydrogen Evolution
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