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The hollow mesoporous silicon oxycarbide (SiOC) ceramics without mixed Si−O−C units (SiO2/C composites) were synthesized through the solvothermal route in Na2CO3 solution, and porous carbon materials were prepared by HF etching. Amorphous SiO2 is transformed into cristobalite SiO2 as the increase in pyrolysis temperature from 1000 to 1400 °C, while the free C (Cfree) content decreases as the elevation of pyrolysis temperature. The carbothermal reduction reaction of SiO2 with Cfree not only results in the formation of SiC nanowires, but also further reduces the C content. However, after HF etching, the C content in carbon materials increases as elevation of pyrolysis temperature, and more micro-/mesopores are created by removal of SiO2. The microstructure and porosity of carbon materials are tailorable by simple changing the pyrolysis temperature. Furthermore, the HF etching results in the insertion of F only in SiO2 and which has no effect on the Cfree. The hierarchical porous structure in conjunction with surface oxygen-containing functional group make the carbon materials obtained at 1400 °C exhibit the good rhodamine B (RhB) and CO2 adsorption performance. The maximum RhB and CO2 adsorption capacity is 130.9 mgg−1 and 1.31 mmolg−1, respectively. [ABSTRACT FROM AUTHOR]

To enhance the electrocatalytic performance of the formic acid oxidation reaction (FAOR), structurally ordered face-centered tetragonal (fct) Pt–Co–Ni/C intermetallic nanoparticles were synthesized via an impregnation reduction method, followed by post heat-treatment. It was found that an ordered intermetallic PtCo phase prevails rather than PtNi as the principal part for the ternary Pt–Co–Ni alloy after being annealed at high temperature, namely, Ni atoms merely serve as the substitute for Co in the lattice of Pt–Co–Ni intermetallics possessing the same atomic stack as PtCo intermetallics. In addition, there is a limitation for Ni to replace Co for the intermetallic PtCo phase, otherwise, most likely excessive Ni would replace the Pt atoms and damage the atomically ordered structure. Benefiting from the ordered structural features and rational introduction of the third transition metal to modify the distance between Pt and Pt atoms, the Pt–Co–Ni/C ordered intermetallic nanoparticles exhibit an enhancement in catalytic activity for the FAOR compared with Pt/C, the PtNi/C alloy and ordered intermetallic PtCo/C nanoparticles. Furthermore, the presence of Ni in the ordered intermetallic Pt–Co–Ni/C catalyst leads to a noticeable improvement in durability compared with the ordered intermetallic PtCo/C catalyst. The present work reveals opportunities for the rational design of ternary electrocatalysts with enhanced catalytic performance for fuel cell applications. [ABSTRACT FROM AUTHOR]

Electrocatalytic production of hydrogen from water is a promising and sustainable strategy. In this study, a simple and general strategy is demonstrated for the synthesis of a polymer-derived, heteroatom-doped carbon supporting MoS2–MoP nanosheets (MoS2–MoP/C), which acts as an efficient hydrogen evolution reaction (HER) catalyst. The unique composition of the MoS2–MoP/C enables catalysis of HER, demonstrating a Tafel slope of 58 mV dec−1 and overpotentials of 102 mV and 130 mV, and is therefore able to deliver current densities of 10 mA cm−2 and 20 mA cm−2, respectively. Moreover, the MoS2–MoP/C nanosheets demonstrate superior long-term durability in acid electrolytes and the developed strategy is easily adapted to large-scale production of efficient electrocatalysts. This excellent HER performance is likely attributed to electronic interactions between P and S, a relatively-high specific surface area of the electrocatalyst (162 m2 g−1), the characteristic nanosheet morphology, and high electrical conductivity, which promotes rapid charge transport and collection. [ABSTRACT FROM AUTHOR]