Pt Nanoparticles on Carbon Nanodots-Titania Composite for Enhanced Electro Oxidation of Alcohol Fuels

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Sandile Surprise Gwebu ◽  
Thabo Matthews ◽  
Wendy Nobanathi Maxakato
Keyword(s):  
Photoelectron Spectroscopy ◽  
Water Solution ◽  
Pt Nanoparticles ◽  
Carbon Nanodots ◽  
Carbon Supports ◽  
X Ray ◽  
Composite Support ◽  
Hydrolysis Method ◽  
Alcohol Fuels ◽  
Platinum Loading

Abstract The severe corrosion of carbon supports in harsh fuel cell conditions has attracted the development of ceramic-based catalyst supports. Platinum nanoparticles supported on the carbon nanodots (CNDs)-titania (TiO2) composite were synthesized in three steps: Firstly, an inorganic support, titania (TiO2) was synthesized by a hydrolysis method. Secondly, the (CNDs-titania) nanocomposite support was prepared by sonicating pre-synthesized carbon nanodots (CNDs) and TiO2 in equal volumes of ethylene glycol/water solution. Lastly, nanosized Pt particles were deposited onto the CNDs-titania composite by a polyol method to form a platinum/(CNDs-titania nanocatalyst. X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), and X-ray difractommetry (XRD) were used to study surface morphology of the synthesized materials. Platinum loading onto the (CNDs-titania) composite support was quantified by ICP-OES. The electrooxidation of alcohol fuels was investigated in acidic electrolytes using chronoamperometric and voltammetric techniques. It was noted that the addition of TiO2 increases electroactivity of the nanocatalysts. The platinum/(CNDs-titania) nanocatalyst exhibited superior electroactivity during methanol and ethanol electrooxidation compared to the platinum/CNDs and Pt/C benchmark standards. Chronoamperometry (CA) curves showed that the platinum/(CNDs-titania) nanocatalyst exhibited outstanding anti-poisoning properties relative to the platinum/CNDs and commercial Pt/C nanocatalysts.

scholarly journals Biosynthesized Highly Stable Au/C Nanodots: Ideal Probes for the Selective and Sensitive Detection of Hg2+ Ions

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 245 ◽  
Author(s):  
Sada Venkateswarlu ◽  
Saravanan Govindaraju ◽  
Roopkumar Sangubotla ◽  
Jongsung Kim ◽  
Min-Ho Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Metal Ions ◽  
Fluorescent Probe ◽  
Photoelectron Spectroscopy ◽  
Industrial Development ◽  
Carbon Nanodots ◽  
Detection Mechanism ◽  
X Ray ◽  
Transmission Electron

The enormous ongoing industrial development has caused serious water pollution which has become a major crisis, particularly in developing countries. Among the various water pollutants, non-biodegradable heavy metal ions are the most prevalent. Thus, trace-level detection of these metal ions using a simple technique is essential. To address this issue, we have developed a fluorescent probe of Au/C nanodots (GCNDs-gold carbon nanodots) using an eco-friendly method based on an extract from waste onion leaves (Allium cepa-red onions). The leaves are rich in many flavonoids, playing a vital role in the formation of GCNDs. Transmission electron microscopy (TEM) and Scanning transmission electron microscopy-Energy-dispersive X-ray spectroscopy (STEM-EDS) elemental mapping clearly indicated that the newly synthesized materials are approximately 2 nm in size. The resulting GCNDs exhibited a strong orange fluorescence with excitation at 380 nm and emission at 610 nm. The GCNDs were applied as a fluorescent probe for the detection of Hg2+ ions. They can detect ultra-trace concentrations of Hg2+ with a detection limit of 1.3 nM. The X-ray photoelectron spectroscopy results facilitated the identification of a clear detection mechanism. We also used the new probe on a real river water sample. The newly developed sensor is highly stable with a strong fluorescent property and can be used for various applications such as in catalysis and biomedicine.

scholarly journals The Preparation and Catalytic Properties of Nanoporous Pt/CeO2 Composites with Nanorod Framework Structures

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 683 ◽  
Author(s):  
Haiyang Wang ◽  
Dong Duan ◽  
Chen Ma ◽  
Wenyu Shi ◽  
Miaomiao Liang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Catalytic Properties ◽  
Structural Parameters ◽  
Active Oxygen Species ◽  
Pt Nanoparticles ◽  
Strong Interactions ◽  
X Ray ◽  
Small Pore ◽  
Melt Spun

Pt/CeO2 catalysts with nanoporous structures were prepared by the facile dealloying of melt-spun Al92−XCe8PtX (X = 0.1; 0.3 and 0.5) ribbons followed by calcination. The phase compositions and structural parameters of the catalysts were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM). The specific surface area and pore size distribution were characterized by N2 adsorption–desorption tests. The catalytic properties were evaluated by a three-way catalyst (TWC) measurement system. The results revealed that the dealloyed samples exhibited a nanorod framework structure. The Pt nanoparticles that formed in situ were supported and highly dispersed on the CeO2 nanorod surface and had sizes in the range of 2–5 nm. For the catalyst prepared from the melt-spun Al91.7Ce8Pt0.3 ribbons, the 50% CO conversion temperature (T50) was 91 °C, and total CO could be converted when the temperature was increased to 113 °C. An X-ray photoelectron spectroscopy (XPS) test showed that the Pt0.3/CeO2 sample had a slightly richer oxygen vacancy; and a H2 temperature-programmed reduction (H2-TPR) test demonstrated its superior adsorption ability for reduction gas and high content of active oxygen species. The experiments indicated that the catalytic performance could be retained without any attenuation after 130 h when water and CO2 were present in the reaction gas. The favorable catalytic activities were attributed to the high specific areas and small pore and Pt particle sizes as well as the strong interactions between the CeO2 and Pt nanoparticles. The Pt nanoparticles were embedded in the surface of the CeO2 nanorods, inhibiting growth. Therefore, the catalytic stability and water resistance were excellent.

Electroless Synthesis of 1.4 nm Pd and Pt Nanoparticles on Self-Assembled Rosette Nanotubes

2011 ◽  
Vol 1301 ◽  
Author(s):  
Rahul Chhabra ◽  
Hicham Fenniri
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Pt Nanoparticles ◽  
Hierarchical Organization ◽  
X Ray ◽  
Force Microscopy ◽  
Rosette Nanotubes ◽  
Atomic Force ◽  
Transmission Electron ◽  
Self Assembled

ABSTRACTElectroless synthesis and hierarchical organization of 1.4 nm Pd and Pt nanoparticles (NPs) on self-assembled Rosette Nanotubes (RNTs) is described. The nucleated NPs are nearly monodisperse and reveal supramolecular organizations guided by RNT templates. Interestingly, the narrow size distribution is attributable to unique templating behavior of RNTs. The resulting metal NP-RNT composites were characterized by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). X-ray Photoelectron Spectroscopy (XPS) was also performed to confirm the nature and composition of RNT-templated NPs.

A dispenser–reactor apparatus applied forin situXAS monitoring of Pt nanoparticle formation

2015 ◽  
Vol 22 (3) ◽  
pp. 736-744 ◽  
Author(s):  
Jocenir Boita ◽  
Marcus Vinicius Castegnaro ◽  
Maria do Carmo Martins Alves ◽  
Jonder Morais
Keyword(s):  
Photoelectron Spectroscopy ◽  
Metallic Nanoparticles ◽  
Pt Nanoparticles ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Two Stages ◽  
X Ray Absorption

In situtime-resolved X-ray absorption spectroscopy (XAS) measurements collected at the PtL3-edge during the synthesis of Pt nanoparticles (NPs) in aqueous solution are reported. A specially designed dispenser–reactor apparatus allowed for monitoring changes in the XAS spectra from the earliest moments of Pt ions in solution until the formation of metallic nanoparticles with a mean diameter of 4.9 ± 1.1 nm. By monitoring the changes in the local chemical environment of the Pt atoms in real time, it was possible to observe that the NPs formation kinetics involved two stages: a reduction-nucleation burst followed by a slow growth and stabilization of NPs. Subsequently, the synthesized Pt NPs were supported on activated carbon and characterized by synchrotron-radiation-excited X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS). The supported Pt NPs remained in the metallic chemical state and with a reduced size, presenting slight lattice parameter contraction in comparison with the bulk Pt values.

Au NPs Loaded Al-MOF@PPy as Excellent Catalyst for the Removal of Organic Pollutants from Water

NANO ◽  
2021 ◽  
pp. 2150002
Author(s):  
Yalu Wu ◽  
Yinyin Xu ◽  
Jingbo Feng ◽  
Yan Zhang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Water Solution ◽  
Catalytic Performance ◽  
Degradation Efficiency ◽  
X Ray ◽  
Inductively Coupled ◽  
Transmission Electron ◽  
Growth Method ◽  
Infrared Spectrometer

The novel Al-MOF@PPy@Au nanocomposites were synthesized by an in-situ growth method. The prepared Al-MOF@PPy@Au nanocomposites were characterized by Transmission Electron Microscope (TEM), Fourier Transform Infrared Spectrometer (FTIR), X-ray powder diffraction (XRD), Inductively Coupled Plasma (ICP) and X-ray photoelectron spectroscopy (XPS). The catalytic properties of the prepared Al-MOF@PPy@Au nanocomposites with different content of Au were investigated. The results illustrated that the Al-MOF@PPy@Au(G) with 27.80 wt.% (w/w) Au obtained good catalytic performance. P-nitrophenol (4-NP), methyl orange (MO), methylene blue (MB) and rhodamine B (RhB) were used to test the catalytic degradation of Al-MOF@PPy@Au(G) nanocomposites. The degradation efficiency of the Al-MOF@PPy@Au(G) nanocomposites for 4-NP, MO, MB and RhB reached 92.12%, 93.84%, 93.19% and 92.44% within 25 min, 7 min, 16 min and 2 min, respectively. The Al-MOF@PPy@Au(G) nanocomposites still have good degradation efficiency and good stability for 4-NP within one month being in water. The Al-MOF@PPy@Au(G) nanocomposites can be applied to the real water solution without causing the change of the degradation efficiency.

TEMPLATE STRATEGY FOR THE SYNTHESIS OF Cu2O–Pt HIERARCHICAL HETEROSTRUCTURES FOR THE DEGRADATION OF METHYLENE BLUE

NANO ◽  
2013 ◽  
Vol 08 (06) ◽  
pp. 1350062 ◽  
Author(s):  
SHIYONG BAO ◽  
HAN ZHU ◽  
PAN WANG ◽  
MEILING ZOU ◽  
MINGLIANG DU ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Methylene Blue ◽  
Photoelectron Spectroscopy ◽  
Pt Nanoparticles ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
X Ray ◽  
Transmission Electron ◽  
Green Route

A facile and green route was introduced to synthesize Pt nanoparticles (PtNPs) immobilized on Cu 2 O octahedrons to form Cu 2 O – Pt hierarchical heterostructure. Transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were employed to study their morphology, chemical and crystallographic properties of the Cu 2 O – Pt hierarchical heterostructure. These novel Cu 2 O – Pt hierarchical heterostructures show fascinating degradations of methylene blue (MB), due to the suppressed electron/hole recombination phenomena and the efficient ability to capture the light.

Chemical Deposition Method for Synthesis of Pt-TiO2 Composite Nanotubes with Photoelectrochemical Activity

2012 ◽  
Vol 465 ◽  
pp. 276-282
Author(s):  
Zhong Hui Gao ◽  
Zhen Duo Cui ◽  
Xian Jin Yang
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Chemical Deposition ◽  
Pt Nanoparticles ◽  
High Density ◽  
Deposition Method ◽  
Photoelectrochemical Activity ◽  
X Ray ◽  
Transmission Electron ◽  
Chemical Deposition Method

Pt nanoparticles were successfully assembled in self-organized TiO2 nanotubes by a chemical deposition method. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were used for characterizing the surface morphology and phase composition. Photocurrent response activity was measured. Different morphology of Pt-TiO2 NTs exhibited different photocurrent generation efficiency. High density Pt nanoparticles depositing on TiO2 NTs decreased the photocurrent of Pt-TiO2 electrodes. It was because the high density Pt nanoparticles could become the recombination centers of photoelectrons and holes.

Volumetric distribution of Pt nanoparticles supported on mesoporous carbon substrates studied by X-ray photoelectron spectroscopy depth profiling

Carbon ◽  
2013 ◽  
Vol 54 ◽  
pp. 389-395 ◽  
Author(s):  
Hsiu-Chu Wu ◽  
Chih-Ching Chang ◽  
Hui-Ping Tseng ◽  
Kang-Ning Lee ◽  
Cheng-Hsiang Tung ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Mesoporous Carbon ◽  
Depth Profiling ◽  
Pt Nanoparticles ◽  
X Ray ◽  
Carbon Substrates
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