One Pot Microwave Irradiation Synthesis of Spherical and Nanotube Titanates Incorporated Reduced Graphene for Efficient Hydrogen Production Photo-Electrocatalytically

2021 ◽  
Author(s):  
Mohamed Mohamed ◽  
Mahmoud M. Hessien ◽  
Mohamed M. Ibrahim
Keyword(s):  
Hydrogen Production ◽  
Microwave Irradiation ◽  
Particle Diameter ◽  
Hybrid Structure ◽  
High Rate ◽  
Solar Irradiation ◽  
High Quantum Yield ◽  
One Pot ◽  
Reduced Graphene ◽  
A Current

Abstract Nanosphere and nanotube titanates (TNT) amalgamated with different graphene oxide (GO) ratios synthesized by one pot microwave irradiation route have presented excellent potential towards hydrogen production photoelectrochemically under solar irradiation. The hybrid nanospherical array of the 50TNT-50GO photocatalyst showed a current density equal 9.2 mA cm-2 at a bias of 0.20 V vs. RHE exceeding those of the nanotubes 30TNT-70GO (4.0 mA cm-2 at 0.38 V) and 10TNT-90GO (3.7 mA cm-2 at 0.4 V). The former electrode also exhibits small Tafel slope value (40 mV dec-1), decreased particle diameter (7 nm), decreased band gap (2.6 eV) and high rate of charges transfer. The hybrid structure elucidation carried out using TEM-SAED, XRD, N2 adsorption, UV-Vis, FTIR and PL techniques approved the interfacial interaction between TNT and GO(RGO) networks that was responsible for the high quantum yield, delay of charges recombination beside the increase in the pore volume.

scholarly journals Effect of Potassium Ions on the Formation of Mixed-Valence Manganese Oxide/Graphene Nanocomposites

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1245 ◽  
Author(s):  
Wooree Jang ◽  
Dae-Young Jeon ◽  
Youn-Sik Lee ◽  
Hye Young Koo
Keyword(s):  
Graphene Oxide ◽  
Manganese Oxide ◽  
Mixed Valence ◽  
High Specific Capacitance ◽  
Potassium Ions ◽  
Electrochemical Supercapacitors ◽  
One Pot ◽  
Graphene Nanocomposites ◽  
Reduced Graphene ◽  
A Current

One-pot synthesis of mixed-valence manganese oxide (MnOx)/potassium ion-doped reduced graphene oxide (rGO) composites for efficient electrochemical supercapacitors is introduced. Using manganese nitrate and potassium permanganate as co-precursors for the MnOx and by directly annealing the rGO without tedious purification steps, as described herein, MnOx/rGO composites with a high specific capacitance of 1955.6 F g−1 at a current density of 1 A g−1 are achieved. It is found that the presence of potassium ions helps in the development of mixed-valence MnOx on the surface of the rGO.

Microwave-assisted synthesis of multiply-twinned Au–Ag nanocrystals on reduced graphene oxide for high catalytic performance towards hydrogen evolution reaction

2016 ◽  
Vol 4 (10) ◽  
pp. 3865-3871 ◽  
Author(s):  
Yuchen Qin ◽  
Xiaoping Dai ◽  
Xin Zhang ◽  
Xingliang Huang ◽  
Hui Sun ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Microwave Irradiation ◽  
Reduced Graphene Oxide ◽  
Hydrogen Evolution Reaction ◽  
Catalytic Performance ◽  
Microwave Assisted Synthesis ◽  
One Pot ◽  
Microwave Assisted ◽  
Reduced Graphene ◽  
Ag Ncs

Multiply-twinned Au–Ag NCs/rGO are prepared by a one-pot method under microwave irradiation and exhibit excellent HER activity and stability.

scholarly journals One-Pot Synthesis of Sulfur-Doped TiO2/Reduced Graphene Oxide Composite (S-TiO2/rGO) with Improved Photocatalytic Activity for the Removal of Diclofenac from Water

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1621
Author(s):  
Marin Kovačić ◽  
Klara Perović ◽  
Josipa Papac ◽  
Antonija Tomić ◽  
Lev Matoh ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Charge Recombination ◽  
Solar Irradiation ◽  
One Pot ◽  
Doped Tio2 ◽  
X Ray ◽  
Sulfur Doping ◽  
Reduced Graphene ◽  
Simulated Solar Irradiation

Sulfur-doped TiO2 (S-TiO2) composites with reduced graphene oxide (rGO), wt. % of rGO equal to 0.5%, 2.75%, and 5.0%, were prepared by a one-pot solvothermal procedure. The aim was to improve photocatalytic performance in comparison to TiO2 under simulated solar irradiation for the treatment of diclofenac (DCF) in aqueous medium. The obtained composites were characterized for physical-chemical properties using thermogravimetric analysis (TGA), X-ray diffractograms (XRD), Raman, scanning electron microscopy (SEM)/energy dispersive X-ray (EDX), Brauner Emmett Teller (BET), and photoluminescence (PL) analyses, indicating successful sulfur doping and inclusion of rGO. Sulfur doping and rGO have successfully led to a decrease in photogenerated charge recombination. However, both antagonistic and synergistic effects toward DCF treatment were observed, with the latter being brought forward by higher wt.% rGO. The composite with 5.0 wt.% rGO has shown the highest DCF conversion at pH 4 compared to that obtained by pristine TiO2, despite lower DCF adsorption during the initial dark period. The expected positive effects of both sulfur doping and rGO on charge recombination were found to be limited because of the subpar interphase contact with the composite and incomplete reduction of the GO precursor. Consequent unfavorable interactions between rGO and DCF negatively influenced the activity of the studied S-TiO2/rGO photocatalyst under simulated solar irradiation.

Synthesis of hydrogenated TiO2–reduced-graphene oxide nanocomposites and their application in high rate lithium ion batteries

2014 ◽  
Vol 2 (24) ◽  
pp. 9150-9155 ◽  
Author(s):  
Jie Wang ◽  
Laifa Shen ◽  
Ping Nie ◽  
Guiyin Xu ◽  
Bing Ding ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Lithium Ion Batteries ◽  
Reduced Graphene Oxide ◽  
Rate Capability ◽  
Lithium Ion ◽  
High Rate ◽  
Capacity Retention ◽  
One Pot ◽  
Reduced Graphene

Hydrogenated TiO2–RGO nanocomposites have been synthesized via a facile one-pot hydrogenation, which exhibit superior rate capability and outstanding capacity retention.

scholarly journals One-Pot Synthesis of TiO2-rGO Photocatalysts for the Degradation of Groundwater Pollutants

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5938
Author(s):  
Stefano Andrea Balsamo ◽  
Roberto Fiorenza ◽  
Marcello Condorelli ◽  
Roberta Pecoraro ◽  
Maria Violetta Brundo ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Textural Properties ◽  
Degradation Process ◽  
Solar Irradiation ◽  
Dichlorophenoxyacetic Acid ◽  
One Pot ◽  
Promising Strategy ◽  
Reduced Graphene ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Green Procedure

A non-conventional approach to prepare titanium dioxide-reduced graphene oxide (TiO2-rGO) nanocomposites based on solar photoreduction is here presented. The standard hydro-solvothermal synthesis of the TiO2-rGO composites requires high temperatures and several steps, whereas the proposed one-pot preparation allows one to obtain the photocatalysts with a simple and green procedure, by exploiting the photocatalytic properties of titania activated by the solar irradiation. The TiO2-rGO catalysts were tested in the solar photodegradation of a widely adopted toxic herbicide (2,4-Dichlorophenoxyacetic acid, 2,4-D), obtaining the 97% of degradation after 3 h of irradiation. The as-prepared TiO2-rGO composites were more active compared to the same photocatalysts prepared through the conventional thermal route. The structural, optical, and textural properties of the composites, determined by Raman, Photoluminescence, Fourier Transform InfraRed (FTIR), UV-vis diffuse reflectance (DRS) spectroscopies, and N2 absorption-desorption measurements, showed as the solar irradiation favors the reduction of graphene oxide with higher efficiency compared to the thermal-driven synthesis. Furthermore, the possible toxicity of the as-synthesized composites was measured exposing nauplii of microcrustacean Artemia sp. to solutions containing TiO2-rGO. The good results in the 2,4-D degradation process and the easiness of the TiO2-rGO synthesis allow to consider the proposed approach a promising strategy to obtain performing photocatalysts.

scholarly journals One-Pot Synthesis of Chlorophyll-Assisted Exfoliated MoS2/WS2 Heterostructures via Liquid-Phase Exfoliation Method for Photocatalytic Hydrogen Production

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2436
Author(s):  
I-Wen P. Chen ◽  
Yan-Ming Lai ◽  
Wei-Sheng Liao
Keyword(s):  
Hydrogen Production ◽  
Synthesis Method ◽  
Solar Irradiation ◽  
One Pot ◽  
Neutral Electrolyte ◽  
The Individual ◽  
Bulk Mos2 ◽  
Ws2 Nanosheets ◽  
Simulated Solar Irradiation ◽  
First Time

Developing strategies for producing hydrogen economically and in greener ways is still an unaccomplished goal. Photoelectrochemical (PEC) water splitting using photoelectrodes under neutral electrolyte conditions provides possibly one of the greenest routes to produce hydrogen. Here, we demonstrate that chlorophyll extracts can be used as an efficient exfoliant to exfoliate bulk MoS2 and WS2 to form a thin layer of a MoS2/WS2 heterostructure. Thin films of solution-processed MoS2 and WS2 nanosheets display photocurrent densities of −1 and −5 mA/cm2, respectively, and hydrogen evolution under simulated solar irradiation. The exfoliated WS2 is significantly more efficient than the exfoliated MoS2; however, the MoS2/WS2 heterostructure results in a 2500% increase in photocurrent densities compared to the individual constituents and over 12 h of PEC durability under a neutral electrolyte. Surprisingly, in real seawater, the MoS2/WS2 heterostructure exhibits stable hydrogen production after solar illumination for 12 h. The synthesis method showed, for the first time, how the MoS2/WS2 heterostructure can be used to produce hydrogen effectively. Our findings highlight the prospects for this heterostructure, which could be coupled with various processes towards improving PEC efficiency and applications.

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