Modeling and performance analysis of duck‐shaped triboelectric and electromagnetic generators for water wave energy harvesting

Triboelectric nanogenerator (TENG) is a newly proposed technology for effectively converting mechanical energy into electricity. Triboelectric nanogenerator has shown a great potential for harvesting the clean and abundant energy of ocean waves. Recently, a duck‐shaped TENG device has been proposed as a lightweight, cost‐effective, highly stable, and efficient system for scavenging the existing energy in water waves. In this paper, a detailed investigation on the performance of the duck‐shaped TENG is presented. Then, a comparative analysis between the TENG device and an equivalent electromagnetic generator (EMG) for wave energy harvesting is performed. The electric output characteristics of both techniques under various mechanical and electrical conditions are obtained. The analysis demonstrates that at a low operating frequency of 2.5 Hz, the TENG and EMG achieve the peak power density of 213.1 and 144.4 W/m³, respectively. The present paper provides guidance for design and optimization of hybrid TENG and EMG technology toward scavenging the blue energy.     

Construction of 1D/0D/2D Zn0.5Cd0.5S/PdAg/g-C3N4 ternary heterojunction composites for efficient photocatalytic hydrogen evolution

A high-efficiency and easy-available approach was developed to obtain a ternary heterojunction composites with advanced hydrogen evolution reaction (HER) performance under visible light by water split. PdAg bimetallic nanoparticles make a close contact interface between g-C₃N₄(CN) and Zn_0.5Cd_0.5S(ZCS). Under visible light irradiation, CN and ZCS are both excited to generate electron-hole pairs, PdAg bimetallic nanoparticles act as a bridge between CN and ZCS. Not only can the photogenerated electrons from CN be captured, but they can also be quickly transferred to the surface of ZCS and participate in the photocatalytic reaction to release H₂, and the recombination of charge carriers between the contact interface of ZCS and CN can be significantly inhibited. In addition, the thin CN layer reduces the photocorrosion of the ZCS and enhances the specific surface area of the composite material. After testing, the composite material with 30 wt% ZCS and 4 wt% PdAg demonstrates hydrogen evolution performance, up to 6250.7 μmol g^?1h^?1, which is 753 times the hydrogen evolution rate of single-component CN and 12.6 times of ZCS/CN. Compared with single-component and two-component photocatalysts, the ternary ZCS/PdAg/CN photocatalyst achieves significantly enhanced photocatalytic activity.     

TiO2 nanoparticle embedded nitrogen doped electrospun helical carbon nanofiber-carbon nanotube hybrid anode for lithium-ion batteries

TiO₂ nanoparticles decorated nitrogen (N) doped helical carbon nanofiber (CNF)-carbon nanotube (CNT) hybrid material is prepared by low-cost electrospinning technique followed by hydrothermal method. Morphological investigations establish helical structure of CNFs with hierarchical growth of CNTs around CNFs. The hybrid material shows a high specific surface area of 295.17 m² g^?1 with nanoporous structure. X-ray photoelectron spectroscopic studies establish Ti–O–C/Ti–C bond mediated charge transfer channel between TiO₂ nanoparticles and carbon structures with the success of N doping in CNFs. The electrospun hybrid material delivered high reversible charge capacities of 316 mAh g^?1 (100th cycle) and 244 mAh g^?1 (100th cycle) at a current density of 75 mA g^?1 and 186 mA g^?1 respectively. The charge capacities obtained for different applied current densities are higher than the conventional graphitic microporous microbeads anode. Results indicate that the hybrid material reported here shows high performance compare to graphite for LIBs.     

Pt-based catalyst decorated by bimetallic FeNi2P with outstanding CO tolerance and catalytic activity for methanol electrooxidation

Subjected to CO poisoning and weak catalytic performance, there are still large barriers to the effective use of direct methanol fuel cells. Therefore, bimetallic FeNi₂P/C hybrid is synthesized by a facile hydrothermal method and low temperature phosphorization process. Subsequently, the as-synthesized FeNi₂P/C is employed as catalytic support to load Pt nanoparticles. Due to the existence of phosphorus and the difunctional effects of Fe and Ni, electrochemical results demonstrate that the prepared Pt–FeNi₂P/C compound exhibits an outstanding catalytic activity of 1125 mA·mg-1 Pt during methanol oxidation in acid solution, tower over that of Pt–FeP₄/C (721 mA·mg^-1_Pt), Pt–Ni₂P/C (588 mA·mg^-1_Pt) and Pt/C-JM (284 mA·mg^-1_Pt), separately. Significantly, bimetallic Pt–FeNi₂P/C hybrid shows the optimal anti poisoning tolerance, which onset potential is negatively shifted 0.2 eV in comparison of Pt/C-JM. Hence, Pt-based catalyst decorated by bimetallic phosphides with excellent anti poisoning tolerance would be a superb material to flourish the catalytic field.     

Enhanced photocatalytic hydrogen evolution based on efficient electron transfer in triphenylamine-based dye functionalized Au@Pt bimetallic core/shell nanocomposite

An efficient photocatalytic hydrogen evolution system based on triphenylamine-based dye functionalized bimetallic Au@Pt core/shell nanocomposite (Au@Pt-TPAD) was reported. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV–vis absorption spectra suggested that Au@Pt-TPAD nanocomposite consisted of a bimetallic nanoparticle with Au core and Pt shell nanostructure. The photoelectrochemical result suggested that photoinduced electrons could efficiently transfer from the triphenylamine derivative molecules to the bimetallic nanoparticles. Photocatalytic results showed that the Au@Pt₂-TPAD bimetallic nanocomposite could be used as a stable photoinduced H₂ evolution photocatalyst. Compared with the monometallic counterpart (Au-TPAD or Pt-TPAD), the bimetallic nanocomposite showed much higher catalytic activity for the photocatalytic hydrogen evolution. The amount of hydrogen evolution on the optimal catalyst under 12 h UV–vis light irradiation was about 37.5 μmol. The enhancement of the photocatalytic activity might be attributed to the synergistic effect between the two metals in bimetallic nanoparticles with core/shell structure. This investigation might open up new opportunities for the development of dye functionalized heterometallic nanocomposite with enhanced photocatalytic performance.     

Fine-tuning catalytic performance of ultrafine bimetallic nickel-platinum on metal-organic framework derived nanoporous carbon/metal oxide toward hydrous hydrazine decomposition

Heterogeneous catalysts with a high performance as well as low cost is pivotal but still challenging for hydrous hydrazine (N₂H₄·H₂O) as a hydrogen storage material. Herein, bimetallic PtNi nanoparticles are well dispersed on nitrogen doped porous carbon/zirconia support (PtNi/NC-ZrO₂). PtNi/NC-ZrO₂ nanocatalysts could be responsive and completely for catalyzing hydrous hydrazine decomposition with a H₂ selectivity of 100% as well as a turnover frequency of 1716 h⁻¹ measured at 323 K, outperforming most heterogeneous metal catalysts. This is mainly attributed that bi-support NC-ZrO₂ can efficiently expedite the electron transfer to metallic NPs and re-construct the electronic structure bimetallic active sites for selectively catalyzing hydrous hydrazine decomposition.     

PdCu bimetallic nanoparticles decorated on ordered mesoporous silica (SBA-15) /MWCNTs as superior electrocatalyst for hydrogen evolution reaction

In the present study, a novel electrocatalyst with excellent catalytic performance based on PdCu bimetallic nanoparticles (NPs) supported on ordered mesoporous silica and multi-walled carbon nanotubes (PdCu NPs/SBA-15-MWCNT) was prepared for electrochemical hydrogen evolution reaction (HER). For this purpose, low-cost mesoporous SBA-15 was synthesized using silica extracted from Stem Sweep Ash (SSA) as an economically attractive silica source. Mesoporous SBA-15 with unparalleled porous structure is a stable support for PdCu bimetallic NPs which prevents the accumulation of PdCu bimetallic NPs and improves its efficiency in the catalytic process. The main advantage of this strategy is low loading of bimetallic catalyst with high catalytic activity. The presence of both mesoporous SBA-15 and MWCNTs materials in PdCu/SBA15-MWCNTs/carbon paste electrode (CPE) increases the metallic active sites and the electrical conductivity of electrode which provides great performance for HER. PdCu/SBA15-MWCNTs-CPE provided small Tafel slope (45 mV dec^?1), low onset potential (~-150 mV), high current density (?165.24 mA cm^?2at -360 mV) and exchange current density (2.51 mA cm^?2) with great durability for HER in H₂SO₄ solution. Analysis of kinetic data suggests that the electrocatalyst controls HER by the Volmer-Heyrovsky mechanism. In addition, studies showed that the presence of sodium dodecyl sulfate (SDS) in electrolyte can decrease the potential of HER and increase the current density.     

Steam-promoted Methane-CO2 reforming by NiPdCeOx@SiO2 nanoparticle clusters for syngas production

We demonstrate a facile aerosol-based approach to fabricate hybrid nanostrcutures, NiPdO_x-CeO₂ nanoparticles deposited on the SiO₂ nanoparticle clusters, for the catalysis of steam-promoted CO₂ reforming with methane. Ultrafine crystallites of active metal and promoter (≈5 nm) are created with tunable cluster sizes and chemical compositions. A superior catalytic performance achieves at low temperature (550 °C): remarkable turnover frequency (≈2 s^?1), tunable H₂/CO ratio (1.1–1.9) and high 100-h operation stability. Incorporation of SiO₂ nanoparticle cluster as support material increases dispersion of active metals and suppresses metal sintering during material synthesis and catalysis. Hybridization with Pd significantly improves the activity of Ni-based catalyst especially ≤600 °C. Addition of steam suppresses the coke formation by > 10 times. The work demonstrates a prototype study of developing bimetallic hybrid nanocatalysts homogeneously dispersed with promoter on the NPC mesoporous support by design, showing promise for the syngas production via synergistic catalysis of methane-CO₂ reforming.     

Enhancing sustainable bioelectricity generation using facile synthesis of nanostructures of bimetallic Co–Ni at the combined support of halloysite nanotubes and reduced graphene oxide as novel oxygen reduction reaction electrocatalyst in single-chambered microbial fuel cells

The present study aims to utilize the high surface area of the nanotube structure of halloysite (HNTs), an aluminosilicate clay, and conductivity of reduced graphene oxide (rGO) as support material for the deposition of nickel (Ni) and cobalt (Co) nanoparticles. With that aim, a novel bimetallic cathode electrocatalyst, Co–Ni @ HNTs-rGO (Catalyst H₃), is developed. This catalyst is characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and Transmission Electron Microscopy (TEM). Catalyst H₃ demonstrates outstanding oxygen reduction reaction (ORR) activity, electrochemical stability, electrocatalytic performance, and lowest resistance in comparison to the other developed catalysts and conventional Pt/C. Catalyst H₃ is used in single-chambered MFCs (microbial fuel cells), where the anode is filled with molasses-laden wastewater. The attained maximum power density in MFC (catalyst H₃) is 455 ± 9 mW/m², which is higher than other catalysts. All the results indicate towards its potential use in MFC application.     

Fabrication of single-walled carbon nanotube/tin nanoparticle composites by electrochemical reduction combined with vacuum filtration and hybrid co-filtration for high-performance lithium battery electrodes

Hybrids consisting of single-walled carbon nanotubes (SWNTs) and tin nanoparticles are prepared on substrates as anode materials for lithium-ion batteries via two different techniques: (i) hybrid co-filtration by simultaneous vacuum filtration of SWNT/tin nanoparticle hybrid solutions and (ii) a combined technique comprised of vacuum filtration and electrochemical reduction. The resulting hybrid composites are of uniform thickness and consist of a homogeneous dispersion of tin nanoparticles in a SWNT network. In the hybrid films, the tin nanoparticles and SWNTs are in close contact with each other and the substrate. The hybrid films exhibit extended cycle life (capacity retention of 80% at 50th cycle), high power characteristics up to 1.75 mA cm⁻², high electrode density up to 5 mg cm⁻², and enhanced reversible capacities (535 mAh g⁻¹ for composite electrode at 50th cycle) because the aggregation of tin nanoparticles is prevented.     

Harnessing low-grade waste heat by operating a hybrid piezoelectric-electromagnetic energy harvester combined with a thermomagnetic engine

This work deals with the development of a thermomagnetic engine driven by using a magnetocaloric material (gadolinium), coupled with both a disk-shaped electromagnetic generator (EMG) and a flexible piezoelectric generator (PENG). The thermomagnetic engine generated the highest rotational speed with an average of 226 ± 1.76% rpm when the temperature differed by 45°C between the hot and cold water jets that operate the engine. At this rotational speed, the EMG and TENG deliver output powers of 8.4 mW (corresponding to the power per unit/volume of 81 W/m³) at a loading resistance of 100 Ω and 74.4 nW (corresponding to the power per unit/volume of 7.2 mW/m³) at a loading resistance of 20 kΩ, respectively. Moreover, the hybrid (EMG-PENG) generator exhibited outstanding performance whose respective short circuit current and open circuit voltage was recorded to be3.6 mA and 7.5 V. It showed a combined power output of 7.8 ± 2.1% mW. The proposed energy harvester demonstrated its capability to charge a 1000 μF capacitor which can be used as an effective power source for diverse smart applications. It was found that the operation of the hybrid (EMG-TENG) generator in line with the thermomagnetic engine holds great potential in harnessing low-grade thermal energy with high added value as compared to common practices in its utilization.     

Carbon-supported PtAu alloy nanoparticle catalysts for enhanced electrocatalytic oxidation of formic acid

The understanding of the electrocatalytic activity of bimetallic nanoparticle catalysts requires the ability to precisely control the composition and phase properties. In this report, we describe a new strategy in the preparation of a series of carbon supported platinum-gold bimetallic nanoparticles with various bimetallic compositions which were loaded onto a carbon black support and subjected subsequently by thermal treatment (Pt_100−mAu_m/C). The Pt_100−mAu_m/C catalysts are characterized by X-ray diffraction (XRD), transmission electron spectroscopy (TEM), and induced coupled plasma-atomic emission spectroscopy (ICP-AES). The XRD pattern for the bimetallic nanoparticles shows single-phase alloy character. This ability enabled us to establish the correlation between the bimetallic composition and the electrocatalytic activity for formic acid (FA) electrooxidation. The electrocatalytic activities of the catalysts toward FA oxidation reaction are shown to strongly depend on the bimetallic PtAu composition. Within a wide range of bimetallic composition, the Pt₅₀Au₅₀/C catalyst shows the highest electrocatalytic activity for the FA oxidation, with a mass activity eight times higher than that of Pt/C. The high performance of the PtAu/C catalyst can be ascribed to the increased selectivity toward the FA dehydrogenation at the decreased availability of adjacent Pt atoms.     

Polymer-based hybrid catalyst of low Pt content for electrochemical hydrogen evolution

Hydrogen is regarded as the most promising fuel to replace conventional fossil fuel. The electrochemical production of hydrogen requires catalyst and development of efficient non-Pt catalysts or catalysts with low Pt content are in demand. Herein, we demonstrate the photochemical synthesis of a hydrogen evolution electrocatalyst poly(α-terthiophene)-Pt nanoparticle hybrid material (polyTT-Pt) of low Pt content and its electrocatalytic activity. The synthesis of polyTT-Pt hybrid material involves the photoinduced electron transfer between α-terthiophene (α-TT) and ${\text{PtCl}}_6^{2\mathrm{?}}$ and the subsequent in situ growth of polymer and Pt nanoparticles. The irradiation of the mixture of α-TT and ${\text{PtCl}}_6^{2\mathrm{?}}$ with sunlamp initiates the oxidative polymerization and reduction of Pt complex to Pt nanoparticles. The polymer has cabbage-like microstructure and the in situ grown Pt nanoparticles have an average size of 1.8 nm. The Pt nanoparticles are embedded into the polymer matrix as well as randomly distributed over the polymer. The hybrid material contains 2.91 wt% of Pt and it shows characteristic electrochemical signature with an electrochemically active surface area of 35.7 m²/g_Pt. The hybrid material polyTT-Pt is electrocatalytically highly active though it contains very small amount of Pt. It efficiently catalyses hydrogen evolution reaction (HER) and the bench mark current density of 10 mA/cm² is achieved at an overpotential of 67 mV. The mass activity of the hybrid catalyst is 1172 mA/mg_Pt at the overpotential of 67 mV. The high activity is ascribed to the high electronic conductivity of the polymer matrix, facile access of electrolyte due to the embedded small nanoparticles and the presence of large number of catalytically active Pt sites. Tafel analysis suggests that the HER follows the Volmer-Tafel mechanism.     

CoNi/CNTs composite as effective and stable electrode for oxygen evaluation reaction in alkaline media

Alloy structure can strongly enhance the chemical resistance of the bimetallic electrodes to be exploited as effective, low electrons transfer resistance and stable electrodes for the oxygen evolution reaction (OER) in the alkaline media. CoNi nanoparticles/carbon nanotubes (CNTs) composite was prepared by calcination of the physically well mixed nickel acetate, cobalt acetate and CNTs mixture under inert atmosphere at 850 °C. To ensure good mixing as well as strong adhesion of the metallic nanoparticles with the CNTs, the metals precursors were dissolved in ethanol first before addition of the carbonaceous partner. Due to the good absorbability of the CNTs to ethanol and the abnormal decomposition of the acetates precursors, oxides-free and well distributed CoNi nanoparticles/CNTs composite was obtained. Moreover, the XRD and TEM analyses affirmed formation of the alloy structure. The electrochemical measurements indicated that the proposed composites have very good catalytic activity toward the OER regardless the bimetallic nanoparticles composition. Numerically, the composites having bimetallic nanoparticles containing 0, 10 and 20 wt% cobalt revealed Tafel slops of 101, 159 and 111 mV dec^?1, and overpotentials of 415, 461 and 485 mV at 10 mA cm^?2 current density, respectively. However, the best stability in the alkaline medium was observed with the composite contains 10 wt% cobalt, while the other two formulations showed fast dissolution. Overall, the present study opens an avenue for the transition metals alloys to be invoked in the OER cells to overcome the high electron transfer resistance associated with the popularly used oxides-based electrodes.     

Novel hybrid two-stage alkali metal thermoelectric converter and thermally regenerative electrochemical cycle to exploit waste heat of solid oxide fuel cell: Performance assessment and optimization

An innovative combination of a two-stage alkali metal thermoelectric converter (TAMTEC), and thermally regenerative electrical cycle (TREC) is employed to utilize the high-quality heat dissipated from solid oxide fuel cell (SOFC) for further electricity production. The superiority and effectiveness of the SOFC-TAMTEC-TREC system are verified compared to existing SOFC-based hybrid systems and sole SOFC. The performance of the system based on energy, exergy, and economic indicators is evaluated by varying the main design parameters. Parametric assessment demonstrates that the SOFC-TAMTEC-TREC system can reach the maximum power density of 12126 W m^?2 with energy and exergy efficiencies of 47.13% and 50.46% as TAMTEC proportional constant increases to 10^7.5 m² and rising SOFC pore and gain diameters to 3.77 × 10^?6 m and 2.5 × 10^?6 m, respectively reduce the cost rate density of system by 3.55 $ h^?1 m^?2. Furthermore, to achieve the maximum power density and exergy efficiency, and minimum cost rate density, NSGA-III multi-criteria optimization, and decision-making techniques are conducted. Outcomes indicate that Shannon entropy leads to the maximum power density of 8597.2 W m^?2 with a 35.94% enhancement relative to a single SOFC and 1 $ h^?1 m^?2 increment in cost rate density of the hybrid system, while LINMAP and TOPSIS ascertain the minimum increase in the cost rate density by 0.6 $ h^?1 m^?2 with 31.04% improvement in power density relative to single SOFC.     

Structural,electrochemical and catalytic activity of Prussian blue analogues embedded with functionalized carbon for solid state battery applications

The nanoparticles of Mn_1.5[Cr(CN)₆]∙mH₂O@Ni_1.5[Cr(CN)₆]∙nH₂O core-shell prussian blue analogues (PBA) embedded with carbon additives (PBA-C) were synthesized and characterized as electrode material for solid state battery application. The impedance spectroscopy and cyclic voltametry were used to study the electrochemical properties by adding functionalized carbon in 1:1 proportion to improve the electrical performance. The value of room temperature electrical conductivity of core-shell PBA and core-shell nanoparticles mixed with vulcan carbon (PBA-C) are found to be 1.574 × 10⁻³ and 1.92 × 10⁻³ Scm⁻¹_, respectively. Using Li₇La₃Zr₂O₁₂ (LZZO) electrolyte, single cell was fabricated with PBA-C material, and studied its charging-discharging cycles, which exhibits higher current density with stable performance for 400 cycles for time slots of 400 min. The study reveals that the PBA core-shell nanoparticles mixed with carbon (PBA-C) may be a potential candidate as an electrode material in the form of a single cell using LZZO electrolyte.     

Pd/Cu bimetallic nanoparticles supported on graphene nanosheets: Facile synthesis and application as novel electrocatalyst for ethanol oxidation in alkaline media

Well distributed Pd/Cu bimetallic nanoparticles supported on graphene nanosheets as novel electrocatalyst has been prepared via a facile synthetic method: started with an electroless deposition route to anchor Cu nanoseeds on graphene nanosheets, followed by a latter displacement reaction to achieve Pd/Cu overlaying nanostructure. The loading density and morphology of bimetallic nanoparticles on graphene are varied by adjusting the initial amount of Cu precursor and reducing agent proportionally. Scanning transmission electron microscopy (STEM) images combining energy dispersive X-ray spectroscopy (EDX) mapping results confirm the existance and distribution of Pd and Cu in the bimetallic nanoparticles, while transmission electron microscopy (TEM) reveals the nanoparticle size and overlaying nanostructure. Cyclic voltammograms tests for the hybrid electrocatalysts in 1.0 M KOH solution show a gradual increase of electrochemically active surface area (EASA) against the increment of nanoparticle loading. Meanwhile, a significantly enhanced tolerance to poisoning of electrocatalyst is observed by cyclic voltammograms curves for ethanol electrooxidation in alkaline media with high I_f/I_b ratios compared to previous research. The large enhancement on I_f/I_b ratios of the hybrid electrocatalysts can be ascribed to the well distributed overlaying bimetallic nanostructure supported on graphene nanosheets. The facilely prepared Pd/Cu/graphene hybrid materials demonstrate vastly superior electrocatalytic properties compared to the commercial Pd/C catalyst, indicating a great potential in fuel cells application.     

Activation effect of silver nanoparticles on the photoelectrochemical performance of mesoporous TiO2 nanospheres photoanodes for water oxidation reaction

This work reports the photodeposition of Ag nanoparticles onto mesoporous TiO₂ (m-TiO₂) pre-formed by the evaporation-induced self-assembly method. Photoanodes of Ag/m-TiO₂ assembled by electrophoretic disclose a superior photoelectrochemical (PEC) performance for water oxidation reaction related to m-TiO₂. The photoanodes physicochemical investigations witness the even arrangement of m-TiO₂ nanospheres particles over the substrates. The PEC study displays a steady photocurrent density of 1 mAcm^?2 at ?1.0 V vs SCE was attained for Ag/m-TiO₂ photoanodes in visible light illumination and it is nearly twofold enhancements in comparison with m-TiO₂ photoanodes. The observed superior PEC nature was attributed to the reduced band-gap energy and charge recombination that caused from the incorporation of plasmonic photodeposited Ag nanoparticles on m-TiO₂ nanospheres photoanodes.     

Engineering of N,P,S-Triple doped 3-dimensional graphene architecture: Catalyst-support for “surface-clean” Pd nanoparticles to boost the electrocatalysis of ethanol oxidation reaction

The engineering of robust electrocatalysts for the ethanol oxidation reaction (EOR) with cost-natural, superior electrocatalytic activity, and stability, is crucial for the scaled-up applications of direct ethanol fuel cells. Herein, a facile bottom-up hydrothermal strategy has been implemented to synthesize N,P,S triple-doped 3-dimensional (3D) graphene architectures (N,P,S-3DG) with interconnected, hierarchical porous structure, followed by Pd nanoparticles were uniformly decorated onto the N,P,S-3DG via solvothermal approach. As fabricated hybrid nanocatalyst, labeled as Pd@N,P,S-3DG, is of charming physicochemical characteristics including large electrochemically active specific surface area, interconnected hierarchical pore network, a satisfactory percentage of heteroatom dopants, uniform distribution of Pd nanoparticles, as well as superior electrocatalytic performance metrics such as high catalytic activity, long-term stability, and tolerance to poisoning. The characterizations have confirmed the strong electrostatic interaction between the Pd nanoparticles and carbonaceous support material, thereby leading to homogeneously anchoring Pd nanoparticles onto 3D architecture and forming of novel active sites as well as synergistically boosting the EOR catalytic activity. The Pd@N,P,S-3DG has offered an enlarged electrochemically active surface area (50.3 m² g^?1), an enhanced catalytic current density of 1784 mA mg^?1_Pd, and outstanding long-term stability, thereby distinctly transcending those of commercial carbonaceous material-supported Pd catalysts. The work is of great importance since it may pave the way for the rational design of low-cost high-performance carbonaceous-based nano-electrocatalysts to be utilized in large-scale energy applications.     

Sea urchin-like mesoporous carbon material grown with carbon nanotubes as a cathode catalyst support for fuel cells

A sea urchin-like carbon (UC) material with high surface area (416 m² g⁻¹), adequate electrical conductivity (59.6 S cm⁻¹) and good chemical stability was prepared by growing carbon nanotubes onto mesoporous carbon hollow spheres. A uniform dispersion of Pt nanoparticles was then anchored on the UC, where the Pt nanoparticles were prepared using benzylamine as the stabilizer. For this Pt loaded carbon, cyclic voltammogram measurements showed an exceptionally high electrochemically active surface area (EAS) (114.8 m² g⁻¹) compared to the commonly used commercial E-TEK catalyst (65.2 m² g⁻¹). The durability test demonstrates that the carbon used as a support exhibited minor loss in EAS of Pt. Compared to the E-TEK (20 wt%) cathode catalyst, this Pt loaded UC catalyst has greatly enhanced catalytic activity toward the oxygen reduction reaction, less cathode flooding and considerably improved performance, resulting in an enhancement of ca. 37% in power density compared with that of E-TEK. Based on the results obtained, the UC is an excellent support for Pt nanoparticles used as cathode catalysts in proton exchange membrane fuel cells.