A promising approach to the synthesis of 3D nanoporous graphitic carbon as a unique electrocatalyst support for methanol oxidation

Advancements in Noble Metal-Decorated Porous Carbon Nanoarchitectures: Key Catalysts for Direct Liquid Fuel Cells

Noble-metal nanocrystals have emerged as essential electrode materials for catalytic oxidation of organic small molecule fuels in direct liquid fuel cells (DLFCs). However, for large-scale commercialization of DLFCs, adopting cost-effective techniques and optimizing their structures using advanced matrices are crucial. Notably, noble metal-decorated porous carbon nanoarchitectures exhibit exceptional electrocatalytic performances owing to their three-dimensional cross-linked porous networks, large accessible surface areas, homogeneous dispersion (of noble metals), reliable structural stability, and outstanding electrical conductivity. Consequently, they can be utilized to develop next-generation anode catalysts for DLFCs. Considering the recent expeditious advancements in this field, this comprehensive review provides an overview of the current progress in noble metal-decorated porous carbon nanoarchitectures. This paper meticulously outlines the associated synthetic strategies, precise microstructure regulation techniques, and their application in electrooxidation of small organic molecules. Furthermore, the review highlights the research challenges and future opportunities in this prospective research field, offering valuable insights for both researchers and industry experts.

High-Affinity-Assisted Nanoscale Alloys as Remarkable Bifunctional Catalyst for Alcohol Oxidation and Oxygen Reduction Reactions

A key challenge in developing fuel cells is the fabrication of low-cost electrocatalysts with high activity and long durability for the two half-reactions, i.e., the methanol/ethanol oxidation reaction (MOR/EOR) and the oxygen reduction reaction (ORR). Herein, we report a conductivity-enhanced bifunctional electrocatalyst of nanoscale-coated Pt-Pd alloys on both tin-doped indium (TDI) and reduced graphene oxide (rGO), denoted as Pt-Pd@TDI/rGO. The mass activities of Pt in the Pt-Pd@TDI/rGO hybrid toward MOR, EOR, and ORR are 2590, 1500, and 2690 mA/mg, respectively. The ORR Pt specific activity and mass activity of the electrocatalyst are 17 and 28 times larger, respectively, than commercial Pt/C catalysts. All these remarkable catalytic performances are attributed to the role of TDI in enhancing the catalytic activity by protecting Pt from oxidation as well as rapid mass/charge transfer due to the synergistic effect between surface Pt-Pd alloys and TDI/rGO.

A novel bioassay based gold nanoribbon biosensor to aid the preclinical evaluation of anticancer properties

In this manuscript we have attempted to develop a novel biosensor based on Au nanoribbons (AuNRs). Initially, Quercetin stabilized AuNPs were prepared and dityrosine peptides was used as a structure directing agent for the synthesis of AuNRs.

State of the art of nanoforest structures and their applications

Forest-like nanostructures, their syntheses, properties, and applications are reviewed.

Stable platinum nanoclusters on genomic DNA-graphene oxide with a high oxygen reduction reaction activity

Nanosize platinum clusters with small diameters of 2–4 nm are known to be excellent catalysts for the oxygen reduction reaction. The inherent catalytic activity of smaller platinum clusters has not yet been reported due to a lack of preparation methods to control their size (<2 nm). Here we report the synthesis of platinum clusters (diameter ≤1.4 nm) deposited on genomic double-stranded DNA–graphene oxide composites, and their high-performance electrocatalysis of the oxygen reduction reaction. The electrochemical behaviour, characterized by oxygen reduction reaction onset potential, half-wave potential, specific activity, mass activity, accelerated durability test (10,000 cycles) and cyclic voltammetry stability (10,000 cycles) is attributed to the strong interaction between the nanosize platinum clusters and the DNA–graphene oxide composite, which induces modulation in the electronic structure of the platinum clusters. Furthermore, we show that the platinum cluster/DNA–graphene oxide composite possesses notable environmental durability and stability, vital for high-performance fuel cells and batteries.

Platinum nanoclusters are well-known catalysts for the oxygen reduction reaction, although the performance of clusters smaller than 2 nm is poorly studied. Here, the authors report 1.4 nm platinum clusters supported on DNA–graphene oxide composites and demonstrate promising electrochemical activity and stability.

Interconnected Pt-nanodendrite/DNA/reduced-graphene-oxide hybrid showing remarkable oxygen reduction activity and stability

Controlling the morphology and size of platinum nanodendrites (PtDs) is a key factor in improving their catalytic activity and stability. Here, we report the synthesis of PtDs on genomic-double-stranded-DNA/reduced-graphene-oxide (gdsDNA/rGO) by the NaBH4 reduction of H(2)PtCl(6) in the presence of plant gdsDNA. Compared to industrially adopted catalysts (i.e., state-of-the-art Pt/C catalyst, Pt/rGO, Pt(3)Co, etc.), the as-synthesized PtDs/gdsDNA/rGO hybrid displays very high oxygen reduction reaction (ORR) catalytic activities (much higher than the 2015 U.S. Department of Energy (DOE) target values), which are the rate-determining steps in electrochemical energy devices, in terms of onset-potential, half-wave potential, specific-activity, mass-activity, stability, and durability. Moreover, the hybrid exhibits a highly stable mass activity for the ORR over a wide pH range of 1-13. These exceptional properties would make the hybrid applicable in next-generation electrochemical energy devices.

Highly selective and stable carbon dioxide uptake in polyindole-derived microporous carbon materials

Adsorption with solid sorbents is considered to be one of the most promising methods for the capture of carbon dioxide (CO₂) from power plant flue gases. In this study, microporous carbon materials used for CO₂ capture were synthesized by the chemical activation of polyindole nanofibers (PIF) at temperatures from 500 to 800 °C using KOH, which resulted in nitrogen (N)-doped carbon materials. The N-doped carbon materials were found to be microporous with an optimal adsorption pore size for CO₂ of 0.6 nm and a maximum (Brunauer-Emmett-Teller) BET surface area of 1185 m(2) g(-1). The PIF activated at 600 °C (PIF6) has a surface area of 527 m(2) g(-1) and a maximum CO₂ storage capacity of 3.2 mmol g(-1) at 25 °C and 1 bar. This high CO₂ uptake is attributed to its highly microporous character and optimum N content. Additionally, PIF6 material displays a high CO₂ uptake at low pressure (1.81 mmol g(-1) at 0.2 bar and 25 °C), which is the best low pressure CO₂ uptake reported for carbon-based materials. The adsorption capacity of this material remained remarkably stable even after 10 cycles. The isosteric heat of adsorption was calculated to be in the range of 42.7-24.1 kJ mol(-1). Besides the excellent CO₂ uptake and stability, PIF6 also exhibits high selectivity values for CO₂ over N₂, CH₄, and H₂ of 58.9, 12.3, and 101.1 at 25 °C, respectively, and these values are significantly higher than reported values.

Graphene oxide-dispersed pristine CNTs support for MnO2 nanorods as high performance supercapacitor electrodes

A MnO2 -CNT-graphene oxide (MCGO) nanocomposite is fabricated using graphene oxide (GO) as a surfactant to directly disperse pristine carbon nanotubes (CNTs) for the subsequent deposition of MnO2 nanorods. The resulting MCGO nanocomposite is used as a supercapacitor electrode that shows ideal capacitive behavior (i.e., rectangular-shaped cyclic voltammograms), large specific capacitance (4.7 times higher than that of free MnO2 ) even at high mass loading (3.0 mg cm(-2) ), high energy density (30.4-14.2 Wh kg(-1) ), large power density (2.6-50.5 kW kg(-1) ), and still retains approximately 94 % of the initial specific capacitance after 1000 cycles. The advanced capacity, rate capability, and cycling stability may be attributed to the unique architecture, excellent ion wettability of GO with enriched oxygen-containing functional groups, high conductivity of CNTs, and their synergistic effects when combined with the other components. The results suggest that the MnO2 -CNT-GO hybrid nanocomposite architecture is very promising for next generation high-performance energy storage devices.

Synthesis of Pt nanopetals on highly ordered silicon nanocones for enhanced methanol electrooxidation activity

Platinum (Pt) nanopetals were electrodeposited on highly ordered silicon nanocones (SiNCs) and explored as the electrocatalyst for methanol oxidation reaction (MOR) for direct methanol fuel cells applications. Highly ordered SiNCs array fabricated using the porous anodic aluminum oxide as the template had a high surface area. Well-dispersed Pt nanopetals possessing high electrocatalytic surface area was synthesized by pulse-electrodeposition on the SiNCs. Pt nanopetals loaded on highly ordered SiNC support exhibited very good catalytic activity for MOR and a high tolerance against CO poisoning, as compared to Pt nanoflowers/flat Si, Pt nanoparticles/flat Si, and many previously reported works. The abundance of a large surface area for facile transport of methanol, SiO(2) sites in the vicinity of the SiNCs, as well as less contact area between the Pt nanopetals catalyst and SiNCs are suggested to be the major factors enhancing the electrocatalytic performance of the Pt nanopetal/SiNC electrode. Moreover, we believe this new nanostructure (Pt nanopetals/SiNCs) will enable many new advances in nanotechnology.