Excellent performance of Pt-C/TiO2 for methanol oxidation:contribution of mesopores and partially coated carbon

Partial deposition of carbon onto mesoporous TiO2 (C/TiO2) were prepared as supporting substrate for Pt catalyst development. Carbon deposition is achieved by in-situ carbonization of furfuryl alcohol. The hybrid catalysts were characterized by XRD, Raman, SEM and TEM and exhibited outstanding catalytic activity and stability in methanol oxidation reaction. The heterogeneous carbon coated on mesoporous TiO2 fibers provided excellent electrical conductivity and strong interfacial interaction between TiO2 support and Pt metal nanoparticles. Methanol oxidation reaction results showed that the activity of Pt-C/TiO2 is 3.0 and 1.5 times higher than that of Pt-TiO2 and Pt-C, respectively. In addition, the Pt-C/TiO2 exhibited a 6.7 times enhanced stability compared with Pt-C after 2000 cycles. The synergistic effect of C/TiO2 is responsible for the enhanced activity of Pt-C/TiO2, and its excellent durability could be ascribed to the strong interfacial interaction between Pt nanoparticles and C/TiO2 support

Geochemical characteristics and sedimentary environment of source rocks in the Qiangtang Basin: New discoveries from the upper Triassic Xiaochaka formation in the Woruoshan Mountain

Clarifying the sedimentary environment and main controlling factors of source rocks is significant for the oil and gas exploration in the Qiangtang Basin. Based on the detailed observation results, this study analyzed the organic geochemical characteristics and trace metals of source rocks in the Upper Triassic Xiaochaka Formation in the Woruoshan Mountain and investigated the depositional conditions and their implications for the formation of source rocks. The source rocks of the Xiaochaka Formation mainly consist of dark mudstones with low-medium abundance of organic matter. They have type II2-III kerogen and middle thermal maturity. This strata had a warm and humid climate during its deposition. Affected by the sea-level fluctuation, the depositional water columns of this strata evolved from freshwater to brackish water and then freshwater from bottom to top. The Xiaochaka Formation deposited in the oxic water columns overall with high paleoproductivity. The formation of the Xiaochaka source rocks in the Woruoshan mainly is the “productivity model” controlled by paleoclimate and freshwater flux. The warm and humid paleoclimate and freshwater transport contributed to the high paleoproductivity of water columns and counteracted the unfavorable preservation conditions. As a result, type Ⅱ2-Ⅲ source rocks were finally formed

Facile Synthesis of Mesoporous MoS2-TiO2 Nanofibers for Ultrastable Lithium Ion Battery Anodes

TiO2 hybrid nanocomposites are promising electrode materials for lithium-ion batteries because of the large specific capacity, excellent rate capability, and high cycling stability. We have developed an effective facile incipient wetness impregnation method that can be used to fabricate novel mesoporous MoS2–TiO2 fibrous nanocomposites. The MoS2–TiO2 nanocomposites exhibited notable electrochemical performance with a high capacity of 120 mA h g−1 at a rate of 40 C and long-term, stable capacity of 124 mA h g−1 with a capacity retention of 75.2 % after 1000 cycles. These results suggest that the structure of mesoporous TiO2 nanofibers composited with a thin, uniform, well-dispersed MoS2 layer improve the rate performance and cycling stability. Such good performance may be derived from the dispersed MoS2 layer, which accelerates the surface electrochemical reactions and offers a stable structure

TiO2 Nanofibers Heterogeneously Wrapped with Reduced Graphene Oxide as Efficient Pt Electrocatalyst Supports for Methanol Oxidation

The exploration of advanced catalyst supports is a promising route to obtain electrocatalysts with high activity and durability. Herein, TiO2 nanofibers heterogeneously wrapped with reduced graphene oxide (rGO) designated as h-rGO@TiO2-rGO were synthesized by a facile deposition and hydrothermal method and served as support for Pt nanoparticles (Pt NPs) used for methanol oxidation. The morphology and electrocatalytic properties of the catalysts were investigated by transmission electron microscopy, X-ray diffraction, Raman spectroscopy, cyclic voltammetry, and chronoamperometry. Pt NPs supported on h-rGO@TiO2-rGO showed uniform dispersion with a mean particle size of 3.4 nm. The electrocatalytic activity and stability of Pt/h-rGO@TiO2-rGO both improved remarkably compared with Pt/rGO and Pt/TiO2. This enhancement originated from the porous structure that promoted the homogeneous dispersion and enlarged the electrochemical active surface area (ECSA) of Pt NPs (ECSACO = 30.95 m2 g−1). Thus, the h-rGO@TiO2-rGO hybrid could be developed as a promising electrocatalyst support material in fuel cells

Unexpected Low-Temperature Performance of Li–O₂ Cells with Inhibited Side Reactions

In this work, we found that the side reactions of both the Li anode and cathode with the electrolyte can be obviously alleviated at low temperature. This favorable merit enables long cycle life of the Li–O₂ cells at low temperature. At 0 °C, the cells can sustain stable cycling of 279 and 1025 cycles at 400 mA g^–1 with limited capacities of 1000 and 500 mA h g^–1, respectively. Even at −20 °C, the cell can be stably cycled for 83 cycles at 200 mA g^–1 with a limited capacity of 500 mA h g^–1

Erratum to: Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition) (Autophagy, 12, 1, 1-222, 10.1080/15548627.2015.1100356

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