Proton-exchange membrane and direct methanol fuel cells (PEMFCs and DMFCs) have attracted much attention as clean energy sources for various applications, such as electric vehicles, portable electronics, and domestic power generation, because of their high power density, high efficiency, and low greenhouse gas emission. [1][2][3][4][5] Especially, the operation of PEMFCs and DMFCs at temperatures above 100 8C is considered to have many advantages, such as the elimination of CO poisoning of the platinum electrocatalyst, faster electrode reaction kinetics, simplified water and heat management, higher energy efficiency, and reduced usage of precious Pt and Pt alloy catalyst. [6,7] However, the state-of-the-art proton-exchange membranes (PEMs) based on perfluorosulfonic acid (PFSA), such as Nafion, are unstable at elevated temperatures (!100 8C) and proton conductivity decreases significantly due to the loss of water from the membrane under conditions of high temperatures or low humidities. [8][9][10] Therefore, development of PEMs with high proton conductivity and stability at elevated temperatures is a major challenge.Great efforts have been dedicated to developing PEMs for operation at elevated temperatures based on mesoporous or nanoporous inorganic materials. Mesoporous inorganic materials have a pore size range of 2-50 nm and are characterized by high specific surface area, nanometer-sized channels or frameworks with an ordered or disordered interconnected internal structure, and high structural stability, which make feasible potential applications as proton-exchange membranes operating at elevated temperatures. [11][12][13][14][15][16][17][18][19][20] Lu and co-workers [21] reported sol-gel-derived mesostructured zirconium phosphates with proton conductivities of about 10 À8 -10 À6 S cm À1. Colomer et al. synthesized nanoporous anatase thin films with conductivity values from 10 À5 to 10 À3 S cm À1 in the range of 33%-81% relative humidity (RH) at room temperature.[22] Li and Nogami [11] prepared proton-conducting mesoporous silica films with conductivity ranging from 10 À6 to 10 À4 S cm À1 under 40%-90% humidity. However, the proton conductivity of the pure mesoporous materials depends significantly on their textural characteristics. For instance, Colomer et al. also reported a proton conductivity of 2.0 Â 10 À2 S cm À1 on mesoporous acid-free silica xerogels and 3.78 Â 10 À2 S cm À1 on a nanoporous anatase thin film at 80 8C and 81% RH. [13,22] Yamada et al. [14] reported a TiO 2 -P 2 O 5 mesoporous nanocomposite with a proton conductivity value of 2 Â 10 À2 S cm À1 at 160 8C. Halla et al. [20] synthesized meso-SiO 2 -C 12 EO 10 OH-CF 3 SO 3 H as a new protonconducting electrolyte and reported a conductivity of 1 Â 10 À3 S cm À1 at room temperature and 90% RH. Although the conductivity values of mesoporous acid-free silica xerogels, meso-SiO 2 -C 12 EO 10 OH-CF 3 SO 3 H or anatase thin films are adequate for fuel cell applications, their performance as an electrolyte in a PEMFC has not been evaluated yet. Ya...

A template-free strategy is exploited to bottom-up synthesize yolk-shell vanadium oxide through a two-step spontaneous assembly of hydrolytically formed subunits in a one-pot process. The unique structured vanadium pentoxide exhibits excellent cathode performance for lithium ion batteries.

A multilayer PEDOT:PSS/WO3 hybrid is prepared via one-pot sequential electrodeposition and it shows significantly enhanced electrochromic properties.

In this article, sulfonic acid-grafted reduced graphene oxide (S-rGO) were synthesized using a one-pot method under mild conditions, and used as Pt catalyst supports to prepare Pt/S-rGO electrocatalysts through a self-assembly route. The structure, morphologies and physicochemical properties of S-rGO were examined in detail by techniques such as atomic force microscope (AFM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The S-rGO nanosheets show excellent solubility and stability in water and the average particle size of Pt nanoparticles supported on S-rGO is ~3.8 nm with symmetrical and uniform distribution. The electrocatalytic properties of Pt/S-rGO were investigated for methanol oxidation reaction (MOR) in direct methanol fuel cells (DMFCs). In comparison to Pt supported on high surface area Vulcan XC-72 carbon (Pt/VC) and Pt/rGO, the Pt/S-rGO electrocatalyst exhibits a much higher electrocatalytic activity, faster reaction kinetics and a better stability. The results indicate that Pt/S-rGO is a promising and effective electrocatalyst for MOR of DMFCs.

A highly ordered mesoporous Nafion membrane with a remarkable water retention ability was synthesized via a micelle templating method with self-assembled Pluronic F108 surfactants and its capability to operate under completely dry gas streams is demonstrated.

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In this study, imidazole-functionalized graphene (G-IMD) was prepared from graphene oxide by a facile one-pot method. The functionalized graphene not only showed improved organic compatibility but also could simultaneously play the roles as cure accelerator and reinforcement for anhydride-cured epoxies. Our results showed that G-IMD could successfully catalyze the curing reaction without adding any routine accelerator. Thermal and mechanical properties of the epoxy/G-IMD nanocomposites were systematically studied at different filler loadings. Compared with neat epoxy resin, tensile strength and Young's modulus of the nanocomposites were enhanced by 97% and 12%, respectively, at only 0.4 wt % G-IMD loading. Dynamic mechanical analysis and electron microscopic results revealed that the drastic improvements in mechanical properties could be attributed to the homogeneous dispersion of G-IMD and covalent bonding at interface, which effectively improved the efficiency of load transfer between the matrix and graphene.