Palladium aerogel as a high-performance electrocatalyst for ethanol electro-oxidation in alkaline media

2017 ◽  
Vol 5 (21) ◽  
pp. 10244-10249 ◽  
Author(s):  
Mehdi Zareie Yazdan-Abad ◽  
Meissam Noroozifar ◽  
Ali Reza Modaresi Alam ◽  
Hamideh Saravani
Keyword(s):  
Surface Area ◽  
Noble Metal ◽  
High Performance ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Alkaline Media ◽  
3D Nanostructures ◽  
Electro Oxidation

Noble metal aerogels as three-dimensional (3D) nanostructures with high surface area and large porosity are known to be exceptional materials that can be applied in the area of catalysis applications.

scholarly journals Polydopamine Doping and Pyrolysis of Cellulose Nanofiber Paper for Fabrication of Three-Dimensional Nanocarbon with Improved Yield and Capacitive Performances

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3249
Author(s):  
Luting Zhu ◽  
Kojiro Uetani ◽  
Masaya Nogi ◽  
Hirotaka Koga
Keyword(s):  
Electrical Conductivity ◽  
Surface Area ◽  
High Performance ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Cellulose Nanofiber ◽  
Supercapacitor Electrode ◽  
Carbohydrate Polymer ◽  
Volume Retention

Biomass-derived three-dimensional (3D) porous nanocarbons have attracted much attention due to their high surface area, permeability, electrical conductivity, and renewability, which are beneficial for various electronic applications, including energy storage. Cellulose, the most abundant and renewable carbohydrate polymer on earth, is a promising precursor to fabricate 3D porous nanocarbons by pyrolysis. However, the pyrolysis of cellulosic materials inevitably causes drastic carbon loss and volume shrinkage. Thus, polydopamine doping prior to the pyrolysis of cellulose nanofiber paper is proposed to fabricate the 3D porous nanocarbons with improved yield and volume retention. Our results show that a small amount of polydopamine (4.3 wt%) improves carbon yield and volume retention after pyrolysis at 700 °C from 16.8 to 26.4% and 15.0 to 19.6%, respectively. The pyrolyzed polydopamine-doped cellulose nanofiber paper has a larger specific surface area and electrical conductivity than cellulose nanofiber paper that without polydopamine. Owing to these features, it also affords a good specific capacitance up to 200 F g−1 as a supercapacitor electrode, which is higher than the recently reported cellulose-derived nanocarbons. This method provides a pathway for the effective fabrication of high-performance cellulose-derived 3D porous nanocarbons.

Hierarchical Nano/Micro-structured Surfaces with High Surface Area/Volume Ratios

2021 ◽  
pp. 1-36
Author(s):  
Ketki Lichade ◽  
Yizhou Jiang ◽  
Yayue Pan
Keyword(s):  
Surface Structure ◽  
Surface Area ◽  
Light Trapping ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Structure Design ◽  
Surface Structures ◽  
Structured Surfaces ◽  
Design And Manufacture

Abstract Recently, many studies have investigated additive manufacturing of hierarchical surfaces with high surface area/volume (SA/V) ratios, and their performance has been characterized for applications in next-generation functional devices. Despite recent advances, it remains challenging to design and manufacture high SA/V ratio structures with desired functionalities. In this study, we established the complex correlations among the SA/V ratio, surface structure geometry, functionality, and manufacturability in the Two-Photon Polymerization (TPP) process. Inspired by numerous natural structures, we proposed a 3-level hierarchical structure design along with the mathematical modeling of the SA/V ratio. Geometric and manufacturing constraints were modeled to create well-defined three-dimensional hierarchically structured surfaces with a high accuracy. A process flowchart was developed to design the proposed surface structures to achieve the target functionality, SA/V ratio, and geometric accuracy. Surfaces with varied SA/V ratios and hierarchy levels were designed and printed. The wettability and antireflection properties of the fabricated surfaces were characterized. It was observed that the wetting and antireflection properties of the 3-level design could be easily tailored by adjusting the design parameter settings and hierarchy levels. Furthermore, the proposed surface structure could change a naturally-hydrophilic surface to near-superhydrophobic. Geometrical light trapping effects were enabled and the antireflection property could be significantly enhanced (>80% less reflection) by the proposed hierarchical surface structures. Experimental results implied the great potential of the proposed surface structures for various applications such as microfluidics, optics, energy, and interfaces.

scholarly journals UV/Vis Light Induced Degradation of Oxytetracycline Hydrochloride Mediated by Co-TiO2 Nanoparticles

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 249 ◽  
Author(s):  
Soukaina Akel ◽  
Redouan Boughaled ◽  
Ralf Dillert ◽  
Mohamed El Azzouzi ◽  
Detlef W. Bahnemann
Keyword(s):  
Surface Area ◽  
Bacterial Infections ◽  
High Performance ◽  
Diffuse Reflectance Spectroscopy ◽  
High Surface ◽  
High Surface Area ◽  
Initial Reaction Rate ◽  
Initial Reaction ◽  
Co Doping ◽  
Vis Spectroscopy

Pharmaceuticals, especially antibiotics, constitute an important group of aquatic contaminants given their environmental impact. Specifically, tetracycline antibiotics (TCs) are produced in great amounts for the treatment of bacterial infections in both human and veterinary medicine. Several studies have shown that, among all antibiotics, oxytetracycline hydrochloride (OTC HCl) is one of the most frequently detected TCs in soil and surface water. The results of the photocatalytic degradation of OTC HCL in aqueous suspensions (30 mg·L−1) of 0.5 wt.% cobalt-doped TiO2 catalysts are reported in this study. The heterogeneous Co-TiO2 photocatalysts were synthesized by two different solvothermal methods. Evonik Degussa Aevoxide P25 and self-prepared TiO2 modified by the same methods were used for comparison. The synthesized photocatalysts were characterized by X-ray powder diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), UV/vis diffuse reflectance spectroscopy (DRS), and N2 adsorption (BET) for specific surface area determination. The XRD and Raman results suggest that Ti4+ was substituted by Co2+ in the TiO2 crystal structure. Uv/visible spectroscopy of Co-TiO2-R showed a substantial redshift in comparison with bare TiO2-R. The photocatalytic performance of the prepared photocatalysts in OTC HCL degradation was investigated employing Uv/vis spectroscopy and high-performance liquid chromatography (HPLC). The observed initial reaction rate over Co-TiO2-R was higher compared with that of Co-TiO2-HT, self-prepared TiO2, and the commercial P25. The enhanced photocatalytic activity was attributed to the high surface area (153 m2·g−1) along with the impurity levels within the band gap (2.93 eV), promoting the charge separation and improving the charge transfer ability. From these experimental results, it can be concluded that Co-doping under reflux demonstrates better photocatalytic performances than with the hydrothermal treatment.

scholarly journals Making an ultralow platinum content bimetallic catalyst on carbon fibres for electro-oxidation of ammonia in wastewater

2019 ◽  
Vol 3 (8) ◽  
pp. 2111-2124 ◽  
Author(s):  
A. M. Pourrahimi ◽  
R. L. Andersson ◽  
K. Tjus ◽  
V. Ström ◽  
A. Björk ◽  
...  
Keyword(s):  
Surface Area ◽  
Bimetallic Catalyst ◽  
High Surface ◽  
High Surface Area ◽  
Hydrogen Gas ◽  
Metal Alloy ◽  
Carbon Fibres ◽  
Platinum Content ◽  
Platinum Coating ◽  
Electro Oxidation

Conductive high surface area carbon fibres with a bimetallic copper–platinum coating are used as electrode for electro-oxidation of wastewater ammonia. The metal alloy is presented as a novel inexpensive catalyst for the generation of hydrogen gas.

scholarly journals High surface area LaNiO3 electrodes for oxygen electrocatalysis in alkaline media

2012 ◽  
Vol 42 (5) ◽  
pp. 325-332 ◽  
Author(s):  
C. O. Soares ◽  
M. D. Carvalho ◽  
M. E. Melo Jorge ◽  
A. Gomes ◽  
R. A. Silva ◽  
...  
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Alkaline Media

scholarly journals Linear-Polyethyleneimine-Templated Synthesis of N-Doped Carbon Nanonet Flakes for High-performance Supercapacitor Electrodes

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1225 ◽  
Author(s):  
Dengchao Xia ◽  
Junpeng Quan ◽  
Guodong Wu ◽  
Xinling Liu ◽  
Zongtao Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Formaldehyde Resin ◽  
Retention Performance ◽  
Competitive Strategies ◽  
Carbon And Nitrogen ◽  
N2 Atmosphere

Novel N-doped carbon nanonet flakes (NCNFs), consisting of three-dimensional interconnected carbon nanotube and penetrable mesopore channels were synthesized in the assistance of a hybrid catalytic template of silica-coated-linear polyethyleneimine (PEI). Resorcinol-formaldehyde resin and melamine were used as precursors for carbon and nitrogen, respectively, which were spontaneously formed on the silica-coated-PEI template and then annealed at 700 °C in a N2 atmosphere to be transformed into the hierarchical 3D N-doped carbon nanonetworks. The obtained NCNFs possess high surface area (946 m2 g−1), uniform pore size (2–5 nm), and excellent electron and ion conductivity, which were quite beneficial for electrochemical double-layered supercapacitors (EDLSs). The supercapacitor synthesized from NCNFs electrodes exhibited both extremely high capacitance (up to 613 F g−1 at 1 A g−1) and excellent long-term capacitance retention performance (96% capacitive retention after 20,000 cycles), which established the current processing among the most competitive strategies for the synthesis of high performance supercapacitors.

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