Constructing Three-Dimensional Hierarchical Architectures by Integrating Carbon Nanofibers into Graphite Felts for Water Purification

Developing high-performance nanostructured sorbents for water treatment is of great importance. Herein, we report a facile strategy to fabricate three-dimensional hierarchical architectures by integrating carbon nanofibers (CNFs) into macroscopic graphite felt (GF) supports. The physicochemical properties of CNF@GF monoliths including surface areas, densities, porosities, and pore structures could be conveniently tuned by varying reaction time. The CNF@GF monoliths were utilized as advanced sorbents for the removal of Pb²⁺, Congo red, organic solvents, and oils from aqueous solutions. The characteristics of adsorption processes including kinetics, isotherms, and regeneration were investigated. It is demonstrated that the CNF@GF exhibits outstanding performance for water treatment in terms of adsorption capacities, recovering, and recyclability. As such, the versatile CNS@GF monoliths show great application potential for water treatment

In Situ Assembly of Ultrathin PtRh Nanowires to Graphene Nanosheets as Highly Efficient Electrocatalysts for the Oxidation of Ethanol

One-dimensional (1D) anisotropic platinum-based nanowires are promising electrocatalysts in polymer electrolyte membrane fuel cells owing to the inherent structural merits. Herein, we report an in situ growth of ultrathin PtRh nanowires (diameters of 2–3 nm) on graphene nanosheets via the oriented attachment pathway. Mechanistic studies reveal that graphene nanosheets play a critical role in the nucleation and growth of PtRh nanowires. The resulting hybrid of PtRh nanowire decorated graphene nanosheets shows outstanding activity and durability toward ethanol electro-oxidation. It exhibits a specific current density of 2.8 mA cm^–2 and a mass-normalized current density of 1 A mg^–1 metal, which are 5.4 and 3.1 times those of the state-of-the-art Pt/C catalyst, respectively. After 2000 cyclic tests, it maintains 86% of the initial electrochemically active surface area, which is larger than that of 63% obtained from the Pt/C catalyst. The superior performance is attributed to the combination of the advantageous 1D morphological motif with the synergistic effects of PtRh alloys and graphene nanosheet support

Constructing Three-Dimensional Hierarchical Architectures by Integrating Carbon Nanofibers into Graphite Felts for Water Purification

Developing high-performance nanostructured sorbents for water treatment is of great importance. Herein, we report a facile strategy to fabricate three-dimensional hierarchical architectures by integrating carbon nanofibers (CNFs) into macroscopic graphite felt (GF) supports. The physicochemical properties of CNF@GF monoliths including surface areas, densities, porosities, and pore structures could be conveniently tuned by varying reaction time. The CNF@GF monoliths were utilized as advanced sorbents for the removal of Pb²⁺, Congo red, organic solvents, and oils from aqueous solutions. The characteristics of adsorption processes including kinetics, isotherms, and regeneration were investigated. It is demonstrated that the CNF@GF exhibits outstanding performance for water treatment in terms of adsorption capacities, recovering, and recyclability. As such, the versatile CNS@GF monoliths show great application potential for water treatment

Synthesis of Ultrafine Pt Nanoparticles Stabilized by Pristine Graphene Nanosheets for Electro-oxidation of Methanol

In this study, the pristine graphene nanosheets (GNS) derived from chemical vapor deposition process were employed as catalyst support. In spite of the extremely hydrophobic GNS surface, ultrafine Pt nanoparticles (NPs) were successfully assembled on the GNS through a surfactant-free solution process. The evolution of Pt NPs in the GNS support was studied using transmission electron microscopy. It was found that the high-energy surface sites in the GNS, such as edges and defects, played a critical role on anchoring and stabilizing Pt nuclei, leading to the formation of Pt NPs on the GNS support. The concentration of the Pt precursor, i.e., H₂PtCl₆ solution had significant effects on the morphology of Pt/GNS hybrids. The resulting Pt/GNS hybrids were examined as catalysts for methanol electro-oxidation. It was indicated that the electrochemical active surface area and catalytic activity of the Pt/GNS hybrids were highly dependent on Pt loadings. The superior activity of the catalysts with low Pt loadings was attributed to the presence of Pt subnanoclusters as well as the strong chemical interaction of Pt NPs with the GNS support