Electrodeposition Of Pt Nanoparticles Research Articles

Controlled Growth of Platinum Nanoparticles during Electrodeposition using Halide Ion Containing Additives

Optimizing platinum (Pt) utilization is a necessary step towards developing affordable electrocatalysts for fuel cells and related technologies. Electrodeposition is a scalable approach to preparing Pt nanoparticles (NPs). Herein, Cl− and Br− ions are used in excess as additives during the electrodeposition of Pt NPs to influence nucleation and growth processes as a means of tuning particle morphology and their electrocatalytic activity. Adding NaCl formed larger particles with urchin-like morphologies while adding NaBr produced smaller, more uniform NPs that were evenly dispersed across the substrate. Mixtures of these two halide ion species improved surface coverage and size distribution of the NPs. Particle size was further decreased, and their surface coverage increased by combining the addition of excess halide ions with using a higher applied potential to initiate “nucleation” followed by a lower applied potential to promote particle “growth.” Mass activity towards the oxygen reduction reaction was the highest for Pt NPs electrodeposited in the presence of Br−. The addition of cetyltrimethylammonium chloride and cetyltrimethylammonium bromide during electrodeposition produced small NPs with an even higher mass activity, which was attributed to the formation of porous nanostructures. This study demonstrates techniques to improve Pt utilization and electrocatalytic activity of electrodeposited Pt NPs.

Activated carbon and poly-o-anisidine(POA) synergistic supported Pt nanoparticles as a highly efficient catalyst for electrocatalytic oxidation of formaldehyde

In this work, different mass percentage of activated carbon (YBC) doped carbon paste electrodes (YBCPE) were firstly prepared, then electrodeposition of Pt nanoparticles was performed at a constant potential -0.1 V vs. Ag|AgCl|KCl (3 M) to prepare working electrodes Pt/YBCPE. It was shown that Pt/YBCPE(16%) exhibits the highest mass activity for formaldehyde oxidation compared to platinum deposited on pure carbon paste electrode (CPE) and other YBCPE(X%) electrodes. Afterwards, poly-o-anisidine (POA) film was prepared by electro-polymerization onto the CPE and YBCPE(16%) in o-anisidine monomer solution at 0.7 V and then Pt nanoparticles were electro-deposited at the POA film surface for fabrication of the Pt/POA/CPE and Pt/POA/YBCPE composite electrodes. The morphology of the composite electrodes was characterized by SEM, TEM, XRD and XPS which revealed that the presence of YBC and POA in the composite electrodes significantly improves the dispersion of Pt nanoparticles on the electrodes. Electrochemical impedance spectroscopy (EIS), chronoamperometry and cyclic voltammetry were used to verify the conductivity and durability of the composite electrode and its electro-catalytic activity. The obtained results indicated that the Pt/POA(16mC)/YBCPE(16%) exhibits excellent electro-catalytic activity towards the formaldehyde oxidation owing to the synergistic effect of the support-catalyst. Some comparisons for the electrooxidation of formaldehyde and the electrooxidation of methanol and formic acid on the composite electrodes also were conducted.

Superb Hydrogen Evolution by a Pt Nanoparticle-Decorated Ni3S2 Microrod Array.

Ni3S2 has attracted great interest as a potential alternative catalyst for the oxygen evolution reaction; however, the formation of sulfur-hydrogen bonds on Ni3S2 suppressed the hydrogen evolution reaction (HER), which remains a significant challenge in interface engineering of Ni3S2 structures for enhancing its HER performance. Herein, we demonstrate an efficient strategy for constructing a Pt nanoparticle-decorated Ni3S2 microrod array supported on Ni foam (Pt/Ni3S2/NF) by electrodeposition of Pt nanoparticles on hydrothermally synthesized Ni3S2/NF. The Pt/Ni3S2/NF heterostructure array exhibits an extremely low overpotential of 10 mV at 10 mA cm-2, surpassing that of commercial Pt/C and representing the best alkaline HER catalysts to date. Impressively, at an overpotential of 0.15 V, Pt/Ni3S2/NF displays a Pt mass activity and a normalized current density (against the electrochemical surface area) of 5.52 A mg-1 and 1.84 mA cm-2, respectively, which are 8.8 and 15.3 times higher compared to those of Pt/C, respectively. In addition, this electrode also shows much enhanced catalytic performance and stability in neutral media. Such enhanced HER activities are attributed to the constructed interface in the Pt/Ni3S2 heterostructure array, which synergistically favor water dissociation and subsequent hydrogen evolution, which is supported by density functional theory calculations.

Synergetic electrochemical HNO3 reduction on the activated-CFP supported nano-Pt electrodes

The electrochemical activated-CFP supported nano-Pt electrode was designed for degrading concentrated HNO3. The influence of pre-thermal treatment of the activated-CFP on the electrodeposition of Pt was investigated, indicating that the decrease in surface oxygen content is beneficial to the electrodeposition of Pt nanoparticles. The nano-Pt/activated-CFP was directly used as a highly reactive electrode for electroreduction of HNO3, showing a high current density for the formation of ammonia ions. This study will provide a possibility for the electrochemical treatment of concentrated HNO3 with the formation of low- and non-toxic byproducts.

Electrochemical synthesis of Pt nanoparticles on gas diffusion layers as cathodes for PEM electrolyzers

Abstract Platinum nanoparticles have been synthesized on gas diffusion layers (GDLs) by means of electrochemical synthesis. Two types of GDLs were used (hydrophobic and hydrophilic) to study the effect of surface properties on the electrodeposition of Pt nanoparticles. Better coverage of Pt nanoparticles has been observed in the case of using a hydrophilic carbon GDL; nanoparticles with lower size were synthesized as well. Characterization of hydrogen evolution reaction by cyclic voltammetry showed a better performance of the electrodes synthesized by electrochemical methods when compared with commercial ones with an equal Pt loading (2 mg·cm-2)

Pt Nanoparticle‐modified Carbon Fiber Microelectrode for Selective Electrochemical Sensing of Hydrogen Peroxide

AbstractWe report a simple approach to the production of carbon fiber‐based amperometric microbiosensors for selective detection of hydrogen peroxide (H2O2), which was achieved by electrometallization of carbon fiber microelectrodes (CFMs) by electrodeposition of Pt nanoparticles. The Pt‐carbon hybrid sensing interface provided a sensitivity of 7711±587 μA ⋅ mM−1 ⋅ cm−2, a detection limit of 0.53±0.16 μM (S/N=3), a linear range of 0.8 μM–8.6 mM, and a response time of <2 sec. The morphologies of the Pt nanoparticle‐modified CFMs were characterized by scanning electron microscopy. To achieve selectivity, permseletive layers, polyphenylenediamine (PPD) and Nafion, were deposited resulting in exclusion of the anionic and cationic interferents, ascorbic acid and dopamine, respectively, at their physiologically relevant concentrations. The resultant sensors displayed a sensitivity to hydrogen peroxide of 1381±72 μA ⋅ mM−1 ⋅ cm−2, and a detection limit of 0.86±0.19 μM (S/N=3). This simple and rapid metallization method converts carbon fiber microelectrodes, which are readily accessible, to microscale Pt electrodes in 2 min, providing a platform for oxidase‐based amperometric biosensors with improved spatial resolution over more commonly used platinum electrode array microprobes.

Low-Loading of Pt Nanoparticles on 3D Carbon Foam Support for Highly Active and Stable Hydrogen Production.

Minimizing Pt loading is essential for designing cost-effective water electrolyzers and fuel cell systems. Recently, three-dimensional macroporous open-pore electroactive supports have been widely regarded as promising architectures to lower loading amounts of Pt because of its large surface area, easy electrolyte access to Pt sites, and superior gas diffusion properties to accelerate diffusion of H2 bubbles from the Pt surface. However, studies to date have mainly focused on Pt loading on Ni-based 3D open pore supports which are prone to corrosion in highly acidic and alkaline conditions. Here, we investigate electrodeposition of Pt nanoparticles in low-loading amounts on commercially available, inexpensive, 3D carbon foam (CF) support and benchmark their activity and stability for electrolytic hydrogen production. We first elucidate the effect of deposition potential on the Pt nanoparticle size, density and subsequently its coverage on 3D CF. Analysis of the Pt deposit using scanning electron microscopy images reveal that for a given deposition charge density, the particle density increases (with cubic power) and particle size decreases (linearly) with deposition overpotential. A deposition potential of −0.4 V vs. standard calomel electrode (SCE) provided the highest Pt nanoparticle coverage on 3D CF surface. Different loading amounts of Pt (0.0075–0.1 mgPt/cm2) was then deposited on CF at −0.4 V vs. SCE and subsequently studied for its hydrogen evolution reaction (HER) activity in acidic 1M H2SO4 electrolyte. The Pt/CF catalyst with loading amounts as low as 0.06 mgPt/cm2 (10-fold lower than state-of-the-art commercial electrodes) demonstrated a mass activity of 2.6 ampere per milligram Pt at 200 mV overpotential, nearly 6-fold greater than the commercial Pt/C catalyst tested under similar conditions. The 3D architectured electrode also demonstrated excellent stability, showing <7% loss in activity after 60 h of constant current water electrolysis at 100 mA/cm2.

Bimetallic Pt-Pd nanostructures supported on MoS2 as an ultra-high performance electrocatalyst for methanol oxidation and nonenzymatic determination of hydrogen peroxide.

The authors report on a composite based electrocatalyst for methanol oxidation and H2O2 sensing. The composite consists of Pt nanoparticles (NPs), Pd nanoflakes, and MoS2. It was synthesized by chemical reduction followed by template-free electro-deposition of Pt NPs. FESEM images of the Pd nanoflakes on the MoS2 reveal nanorod-like morphology of the Pd NPs on the MoS2 support, whilst FESEM images of the Pt-Pd/MoS2 composite show Pt NPs in high density and with the average size of ~15nm, all homogeneously electrodeposited on the Pd-MoS2 composite. A glassy carbon electrode (GCE) was modified with the composite to obtain an electrode for methanol oxidation and H2O2 detection. The modified GCE exhibits excellent durability with good catalytic efficiency (the ratio of forward and backward peak current density, If/Ib, is 3.23) for methanol oxidation in acidic medium. It was also used to sense H2O2 at an applied potential of -0.35V vs. Ag|AgCl which can be detected with a 3.4μM lower limit of detection. The sensitivity is 7.64μAμM-1cm-2 and the dynamic range extends from 10 to 80μM. This enhanced performance can be explained in terms of the presence of higher percentage of metallic 1T phase rather than a semiconducting 2H phase in MoS2. In addition, this is a result of the high surface area of MoS2 with interwoven nanosheets, the uniform distribution of the Pt NPs without any agglomeration on MoS2 support, and the synergistic effect of Pt NPs, Pd nanoflakes and MoS2 nanosheets. In our perception, this binder-free nano-composite has promising applications in next generation energy conversion and in chemical sensing. Graphical abstract A composite consisting of palladium nanoflakes and molybdenum disulfide was decorated with platinum nanoparticles and then placed on a glassy carbon electrode which is shown to be a viable electrocatalyst for both methanol oxidation and detection of hydrogen peroxide.

Highly stable core–shell Pt-CeO2 nanoparticles electrochemically deposited onto Fecralloy foam reactors for the catalytic oxidation of CO

The sequential electrodeposition of Pt nanoparticles and CeO2 protective layers has been explored as a simple method to prepare structured catalytic reactors characterized by a core–shell metal-metal oxide active phase directly anchored onto metallic (Fecralloy) 3D open foam substrates. The application of a CeO2 overlayer onto preformed Pt nanoparticles promoted the intrinsic catalytic activity for CO oxidation and induced a remarkable stabilization effect against sintering and extensive reconstruction of the active phase up to 800°C.

Rose petal and P123 dual-templated macro-mesoporous TiO2 for a hydrogen peroxide biosensor

In this work, highly ordered macro-mesoporous TiO2 has been successfully synthesized using fresh rose petals and P123 (EO20PO70EO20) as dual templates through a simple soaking and calcining process. Characterization of the as-prepared TiO2 indicated that the mesoporous structure of the TiO2 was highly ordered, with a pore diameter of approximately 3nm. After electrodeposition of Pt nanoparticles onto the TiO2 as an electron transfer enhancer and the immobilization of horseradish peroxidase (HRP) onto the TiO2-modified electrode, a biosensor for detecting hydrogen peroxide (H2O2) was realized. This biosensor showed a wide linear detection range from 5μM to 8mM and a low detection limit of 1.65μM with good stability and high selectivity, suggesting that the sensor is well-suited for the detection of H2O2.

Binder free platinum nanoparticles decorated graphene-polyaniline composite film for high performance supercapacitor application

Conventional supercapacitors use insulating binders with active materials for fabricating working electrodes. Use of such binder reduces electrical conductivity of the electrode, thus causing energy wastage of supercapacitor. To overcome this, herein, we report binder free Platinum (Pt) nanoparticles (NPs) decorated Graphene–Polyaniline (Gr-PANi) composite modified electrode for supercapacitor application. Pt decorated Gr-PANi composite was prepared by template-free electrochemical polymerization method followed by electro-deposition of Pt NPs. Detailed structural and chemical characterization of the composite were done by SEM, EDX spectroscopy and Raman scattering. FESEM image of Pt decorated Gr-PANi composite revealed nano-fibrous structure of PANi (average diameter of 50–100nm) with Pt NPs uniformly deposited on its surface. Interconnected network of PANi nanofibers made matrix highly porous, thereby, providing an improved electrode/electrolyte interface area and shorter diffusion lengths for electrolytic ions. The electrochemical behavior of Pt NPs decorated Gr-PANi composite film was studied by cyclic voltammetry while galvanostatic charge–discharge measurements were carried out to investigate its capacitive performances. Pt decorated Gr-PANi composite based supercapacitor exhibited higher specific capacitance of 922.5F/g which was∼1.75 folds greater than that of only Gr-PANi based electrode at same current density (1A/g) and much higher than previously reported Gr-PANi composite based supercapacitors. The developed Pt decorated Gr-PANi composite modified electrode exhibited charge capacity of 0.57 mAh/cm2 and discharge capacity of 0.29 mAh/cm2 which were 2.4 folds and 1.81 folds higher than only Gr-PANi electrode respectively. The significant improvement in specific capacitance with excellent sustainability to higher current, superior rate capability, charge storage capacity and cycling stability can be attributed to the synergistic effect of electrical double-layer capacitance and pseudocapacitance resulting from Gr and PANi respectively and excellent catalytic ability of Pt NPs. The as-synthesized Pt decorated Gr-PANi composite offers simple, promising and binder free electrode material for energy storage devices.

Electrochemical preparation of nanostructured CeO2-Pt catalysts on Fe-Cr-Al alloy foams for the low-temperature combustion of methanol

Pt-based structured catalysts for the low-temperature combustion of methanol have been prepared by electrochemical methods, using Fe-Cr-Al alloy (Fecralloy) foam supports. Among the strategies investigated, pulsed electrodeposition of Pt nanoparticles from an H2PtCl6 solution, followed by cathodic electrodeposition of CeO2 thin films from a nitrate bath was the most successful. Pt loading and surface area were measured by ICP-MS and cyclic voltammetry, respectively. Although the presence of a CeO2 film decreased the Pt surface area accessible to electrolyte it enhanced the performance of the catalysts towards methanol combustion, without affecting the activation energy of the process, due to the formation of additional active sites along the interface of CeO2-coated Pt nanoparticles.

Hydrogen Adsorption Properties of Carbon Nanotubes and Platinum Nanoparticles from a New Ammonium-Ethylimidazolium Chloroplatinate Salt.

Self-supporting membranes built entirely of carbon nanotubes have been prepared by wet methods and characterized by Raman spectroscopy. The membranes are used as supports for the electrodeposition of Pt nanoparticles without the use of additional additives and/or stabilizers. The Pt precursor is an ad hoc synthesized ammonium-ethylimidazolium chloroplatinate(IV) salt, [NH3 (CH2 )2 MIM)][PtCl6 ]. The Pt complex was characterized using NMR spectroscopy, XRD, ESI-MS, and FTIR spectroscopy. The interaction between the Pt-carbon nanotubes nanocomposites and hydrogen is analyzed using electrochemical and quartz microbalance measurements under near-ambient conditions. The contribution of the Pt phase to the hydrogen adsorption on nanotube is found and explained by a kinetic model that takes into account a spillover event. Such a phenomenon may be exploited conveniently for catalysis and electrocatalysis applications in which the hybrid systems could act as a hydrogen transfer agent in specific hydrogenation reactions.

Fabrication of phenazopyridine sensor based on electrodeposition of Pt nanoparticles on H–CaFe–Cl-layered double hydroxide film modified glassy carbon electrode

A sensitive phenazopyridine sensor has been developed by electrodeposition of Pt nanoparticles on H–CaFe–Cl-layered double hydroxide modified glassy carbon. Electrochemical impedance spectroscopy and cyclic voltammetry were used to investigate the formation of H–CaFe–Cl-layered double hydroxide film and Pt nanoparticles on the electrode surface. The properties of modified electrode were characterized by field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. The fabricated sensor exhibits outstanding electrocatalytic activities toward the oxidation of phenazopyridine. The oxidation peak current was proportional to the concentration of phenazopyridine from 5×10−8 to 6.9×10−4molL−1 including two linear segments with a detection limit of 6.3×10−9molL−1 at signal to noise ratio of 3. The proposed method was examined as a selective, simple and precise method for voltammetric determination of phenazopyridine in real samples with satisfactory results.

Enhanced catalytic performance of Pt/TNTs composite electrode by reductive doping of TNTs

This paper introduced a novel method to fabricate Pt/TiO2 nanotube arrays (TNTs) composite electrode with enhanced catalytic performance toward methanol oxidation. The TNTs supports were pretreated by reductive doping, and Pt nanoparticles were subsequently implanted in the TNTs by electrochemical deposition. Effects of the reductive doping on the microstructure and electrocatalytic activity of Pt/TNTs composite electrode were studied. The results show that Ti3+ is produced by the reductive doping of TNTs, which makes the resistance of TNTs efficiently decreased. The increased conductivity of TNTs facilitated the subsequent electrodeposition of Pt nanoparticles, leading to the smaller size of Pt particles and higher deposition rate. The Pt/reductive doped TNTs electrode prepared from 4h electrodeposition exhibit excellent electrocatalytic activity, for which the peak current density is as high as 76.6mAcm−2 and the mass transfer coefficient is obviously increased.

Electrodeposition of Pt Nanoparticles on New Porous Graphitic Carbon Nanostructures Prepared from Biomass for Fuel Cell and Methanol Sensing Applications

We investigate the performance of an iron-doped porous graphitic carbon nanostructure (GCN) prepared from biomass for application in fuel cells and electrochemical sensors. By using cyclic voltammetry (CV), we show that these GCNs have appropriate electrochemical properties and exhibit a significantly high catalytic activity toward oxygen reduction without Pt catalyst. The GCNs were also used as a substrate for electrodeposition of Pt nanoparticles (Pt-NPs) to study electro-oxidation and sensing of methanol. The composition of Pt-NPs and GCNs show high catalytic affinity toward electro-oxidation of methanol in an acidic medium. The modified electrode with Pt-NPs and GCNs also could act as an effective sensor for determination of methanol concentration in natural pH. This sensor enables determination of methanol with a wide linear range (0.05–21.73 mM), low detection limit (20 μM, at S/N of 3), high sensitivity (11.49 μA cm−2 mM−1), and long-term stability (over 40 days). The present sensor also has low working potential (0.17 V) making it less prone to an interference effect. The resulting electrodes were characterized by using scanning electron microscopy, energy dispersive X-ray spectroscopy, and CV.

Preparation of Pt/poly(2-Methoxyaniline)/multi-walled carbon nanotube nanocomposite and its application for electrocatalytic oxidation of methanol

In this work, a Pt-based nanocomposite has been fabricated by electrodeposition of Pt nanoparticles (about 80nm) on a porous poly(2-Methoxyaniline)/multi-walled carbon nanotube (P2MA/MWCNT) film which was prepared via electropolymerization method. The electrochemical response of the P2MA/MWCNT film was, at least, 8 times higher than that of the film in the absence of MWCNT. After preparation of the P2MA/MWCNT matrix, electrodeposition at a fixed potential (−0.20V vs. Ag|AgCl|KCl (3M)) in 0.5M H2SO4 solution containing 5.0mM H2PtCl6 was employed for dispersion of the Pt nanoparticles. The as-formed nanocomposite was characterized by scanning electron microscopy, energy dispersive spectroscopy and electrochemical methods. Methanol oxidation reaction (MOR) has been studied on the prepared catalyst by using various electrochemical techniques. The results demonstrated that the Pt/P2MA/MWCNT nanocomposite acts as a more efficient electrocatalyst for MOR. Ability of the modified electrode towards electrocatalytic oxidation of formaldehyde as an intermediate in the MOR has also been investigated.

Pt nanoparticle modified single walled carbon nanotube network electrodes for electrocatalysis: Control of the specific surface area over three orders of magnitude

The electrodeposition of Pt nanoparticles (NPs) on two-dimensional single walled carbon nanotube (SWNT) network electrodes is investigated as a means of tailoring electrode surfaces with a well-defined amount of electrocatalytic material. Both Pt NP deposition and electrocatalytic studies are undertaken using the microcapillary electrochemical method (MCEM), enabling multiple microscale measurements to be performed quickly and easily on the same SWNT sample. Using this approach, Pt catalysts with high specific surface areas relative to the geometric electrode area (defined by the meniscus contact of the MCEM probe with the Si/SiO2 substrate bearing the SWNT network) can be controlled precisely over three orders of magnitude. This enables the influence of the specific surface area of an electrocatalyst on activity to be investigated, as demonstrated by studies of the oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR).

A Pt Nanoparticle Electrode for Nitrite Determination in Solution

In this study, a Pt nanoparticle electrode which had advantages of high selectivity, accuracy, and anti-interference capacity was successfully fabricated for quantitative measurement and analysis of nitrite concentration under neutral conditions with various interference ions. Current-time curve was used for the electrodeposition of Pt nanoparticles on the surface of the pretreated Pt disk electrode, and the deposition time was 100 seconds. The prepared nano-Pt electrode had an electrochemical catalytic reductive activity for nitrite. Nitrite reductive peak current was linear correlation with nitrite concentrations in solutions. The life time of the modified electrode was at least 150 days at room temperature (at least 1000 determinations). The present method is simple, does not require any pre-treatment procedure, and does carry very good repeatability and reproducibility. Moreover, the proposed electrochemical method was also validated by spectrophotometry in artificial and real wastewater samples.

A droplet-based microfluidic electrochemical sensor using platinum-black microelectrode and its application in high sensitive glucose sensing

We describe a droplet-based microfluidic electrochemical sensor using platinum-black (Pt-black) microelectrode. Pt-black microelectrode was generated by electrodeposition of Pt nanoparticles on bare Pt microelectrode. Scanning electron microscope (SEM) image displays a flower-like microstructure of Pt nanoparticels. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) indicate that the Pt-black efficiently decreased the charge transfer resistance and improved the electrocatalytic activity towards oxidation of hydrogen peroxide (H2O2). Compared with bare Pt microelectrode, the current response on Pt-black microelectrode increased 10.2 folds. The effect of applied potential and electrodeposition time has been investigated in detail. The proposed sensor was validated by performing enzyme activity assay in flowing droplets. For demonstration, glucose oxidase (GOx) is chosen as the model enzyme, which catalyzes the oxidation of β-d-glucose to the product H2O2. The enzyme activity of GOx was evaluated by measuring the electrochemical current responding to various glucose concentrations. And the results indicate that this microfluidic sensor holds great potential in fabricating novel glucose sensors with linear response up to 43.5mM. The analytical applications of the droplet-based microfluidic sensor were tested by using human blood serum samples. Reproducibility, interferences, and long-term stability of the modified electrode were also investigated. The present approach shows the feasibility and great potentials in constructing highly sensitive and low-consumption sensors in the field of droplet microfluidics.