Microwave-Assisted Synthesis of Titanate Nanotubes Loaded with Platinum with Enhanced Selectivity for Photocatalytic H2 Evolution from Methanol

NANO ◽  
2020 ◽  
Vol 15 (10) ◽  
pp. 2050129
Author(s):  
Hsiu-Yu Chen ◽  
Shang-Lien Lo ◽  
Hsiang-Ling Chang
Keyword(s):  
Hydrogen Production ◽  
Visible Region ◽  
Binding Energies ◽  
Raw Material ◽  
Titanate Nanotubes ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Tauc Plot ◽  
Allowed Transition ◽  
Metal Support Interaction

Titanate nanotubes (TNTs) fabricated through microwave-assisted synthesis were examined for their ability to catalyze hydrogen production from a 20% v/v methanol solution under UV and visible light irradiation. Herein, TiO2 was used not only as the raw material for TNT synthesis but also as a reference support to compare its performance with that of TNTs. The UV–Vis spectral analyses of the TNT composites showed greater shifts toward the visible region after Pt loading than the spectra of Pt/TiO2. Moreover, using the Kubelka–Munk equation and Tauc Plot method, we determined that the direct allowed transition in TNT composites was more probable than the indirect allowed transition. The photocatalytic performances were evaluated by measuring the hydrogen production, and the experimental results showed that Pt/TNTs exhibited higher activity than Pt/TiO2. Furthermore, bare TNTs and Pt/TNTs showed lower CO generation than bare TiO2 and Pt/TiO2. As such, TNT composites enhanced the photocatalytic selectivity for H2 generation from formic acid to a greater extent than Pt/TiO2, because the kinetic diameter of CO (0.38[Formula: see text]nm) is larger than that of CO2 (0.33[Formula: see text]nm). This result may be attributed to the inability of CO to diffuse into the pores of TNTs because of the diameter difference. Also, XPS results showed negative shifts of Pt binding energies and positive shifts of Ti binding energies due to the strong metal-support interaction between Pt and TNTs. Thus, the remarkably high photocatalytic efficiency of TNT composites facilitates their application as promising photocatalysts.

Microwave-Assisted Synthesis of Ni/CNTs Nanocomposites for Hydrogen Production from Hydrolysis of NaBH4

2012 ◽  
Vol 622-623 ◽  
pp. 816-820
Author(s):  
Fang Li ◽  
Qi Ming Li ◽  
Hern Kim
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Production ◽  
Hydrogen Generation ◽  
Generation Rate ◽  
Ni Catalyst ◽  
Microwave Assisted Synthesis ◽  
Environment Friendly ◽  
Microwave Assisted ◽  
Hydrolysis Of ◽  
Supported Ni

Hydrogen production from NaBH4 hydrolysis is very important for environment-friendly fuel cells. Here Ni/CNTs nanocomposites were prepared by microwave-assisted method and used as the catalyst for catalytic hydrolysis of NaBH4. XRD and SEM characterization showed that uniform Ni/CNTs nanocomposites can be obtained through microwave heating and solvent optimization. Ni/CNTs nanocomposites exhibit excellent catalytic activity in the hydrolysis of NaBH4, i.e., the average hydrogen generation rate at 25°C is 840ml.min-1.g-1 for the CNTs-supported Ni/CNTs, while the hydrogen generation rate of 86ml.min-1.g-1 for unsupported Ni catalyst. Compared with the unsupported Ni catalyst, Ni/CNTs nanocomposites presented higher catalytic activity for hydrolysis of aqueous NaBH4 solution.

scholarly journals Microwave-Assisted Synthesis of Porous ZnO/SnS2Heterojunction and Its Enhanced Photoactivity for Water Purification

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
A. B. Makama ◽  
A. Salmiaton ◽  
E. B. Saion ◽  
T. S. Y. Choong ◽  
N. Abdullah
Keyword(s):  
Visible Light ◽  
Synergetic Effect ◽  
Visible Region ◽  
Microwave Assisted Synthesis ◽  
Fixed Amount ◽  
X Ray ◽  
Enhanced Absorption ◽  
Microwave Assisted ◽  
Degradation Rates ◽  
Photocatalytic Activities

Porous ZnO/SnS2nanocomposites with adjustable SnS2contents were prepared via microwave-assisted heating of different aqueous solutions of SnS2precursors in the presence of fixed amount of ZnCO3nanoparticles at pH 7. The structures, compositions, BET specific surface areas, and optical properties of the as-prepared products were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, N2adsorption, and UV-Vis absorption spectra. Photocatalytic activities of the samples were tested by the removal of aqueous ciprofloxacin,CrVI, and methylene blue under visible-light (λ>420 nm) irradiation. The experimental results reveal that the as-prepared heterogeneous nanostructures exhibit much higher visible-light-driven photocatalytic activity for the degradation of the pollutants than pure SnS2nanocrystals. The photocatalytic degradation ratesCt/C0of the pollutants for the most active heterogeneous nanostructure are about 10, 49, and 9 times higher than that of pure SnS2. The enhanced photocatalytic activities exhibited by the heterojunctions could be ascribed to the synergetic effect of enhanced absorption in the visible region and the reduced rate of charge carrier recombination because of efficient separation and electron transfer from the SnS2to ZnO nanoparticles.

Microwave-assisted synthesis, characterization, cell imaging of fluorescent carbon dots using l-asparagine as precursor

2019 ◽  
Vol 43 (8) ◽  
pp. 3323-3331 ◽  
Author(s):  
Xi Wang ◽  
Tian Gao ◽  
Mian Yang ◽  
Jie Zhao ◽  
Feng-Lei Jiang ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Cell Imaging ◽  
Raw Material ◽  
Microwave Assisted Synthesis ◽  
Time Saving ◽  
Microwave Assisted ◽  
Fluorescent Carbon Dots ◽  
Fluorescent Carbon

Structure-analyzed carbon dots fabricated from a green raw material by a time-saving method.

Microwave-Assisted Synthesis and Photocatalytic Activity of Quantum-Sized ZnO

2011 ◽  
Vol 284-286 ◽  
pp. 866-870 ◽  
Author(s):  
Wen Guo Xu ◽  
Cheng Xiang Ma ◽  
Shi Xiang Lu ◽  
Lian Dai ◽  
Hai Feng Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Degradation Rate ◽  
Sol Gel ◽  
Heating Time ◽  
Raw Material ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Lithium Hydroxide Monohydrate ◽  
Hydroxide Monohydrate ◽  
Reactive Blue 4

ZnO was prepared using zinc acetate dehydrate (Zn(CH3COO)2·2H2O) and lithium hydroxide monohydrate (LiOH·H2O) as raw material through a microwave-assisted sol-gel method. The prepared ZnO presents the wurtzite structure. The influence of different reaction temperature and heating time to the size of ZnO was researched. The photocatalytic activity of ZnO was evaluated by the degradation rate of C.I. Reactive Blue 4 in aqueous solution. The particle size of ZnO is about 4.33 nm at the reaction condition of 50°C for 10 min and the photocatalytic performance is the best. The degradation rate of C.I. Reactive Blue 4 could exceed 75% in 30 min at room temperature when the initial concentration of C.I. Reactive Blue 4 was 40 mg/L and the concentration of the quantum-sized ZnO was 0.1 g/L.

scholarly journals Microwave-Assisted Synthesis and Characterization of Poly(L-lysine)-Based Polymer/Carbon Quantum Dot Nanomaterials for Biomedical Purposes

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3825 ◽  
Author(s):  
Janus ◽  
Piątkowski ◽  
Radwan-Pragłowska
Keyword(s):  
Carbon Nanomaterials ◽  
Water Solubility ◽  
Luminescent Properties ◽  
Dermal Fibroblasts ◽  
Biologically Active ◽  
Raw Material ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Low Cytotoxicity ◽  
Metal Ions Detection

Carbon nanomaterials in the form of quantum dots have a high potential due to their luminescent properties and low cytotoxicity which allows their use in optical probes for use in bioimaging and biodetection. In this article, we present a novel type of nanomaterials and their obtainment method under microwave-assisted conditions using poly(L-lysine) as a raw material. The ready products were characterized over their chemical structure, pH-dependent fluorescence properties and cytotoxicity on human dermal fibroblasts. Moreover, their antioxidant activity as well as ability to biologically active molecules (vitamins) and heavy metal ions detection was evaluated. The results confirmed the obtainment of biocompatible nanomaterials with advanced properties and good water solubility according to sustained development principles.

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