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This work reports the use of the metal‐support interaction strengthening through defect engineering and single atom adsorption to the supports to increase the catalytic activities of metals. Specifically, the plasma treated TiO2 nanowires with the Ir nanoparticle growth and the Sr single atom adsorption (the Ir@Sr‐p‐TiO2 NWs) are synthesized and demonstrated to be efficient catalysts for OER and HER. They only need overpotentials of 250 and 32 mV to drive 10 mA cm−2 for OER and HER, respectively. Their OER and HER activities are much higher than the commercial IrO2 and Pt/C. The high activities of the Ir@Sr‐p‐TiO2 NWs mainly arise from the strengthened metal‐support interactions between the Ir nanoparticles and the p‐TiO2 NWs, achieved by the plasma generated oxygen defects (Vo·) and the Sr adsorption on the p‐TiO2 NWs. Analysis and DFT calculations indicate that the Vo· and Sr adsorption can promote the charge transfer from the p‐TiO2 NWs to the Ir nanoparticles, optimizing the adsorptions of the OER and HER intermediates on the O‐ and H‐covered Ir nanoparticles. Additionally, the strong metal‐support interactions can increase the stabilities of the Ir NPs against the chemical corrosions, increasing the OER and HER durabilities of the Ir@Sr‐p‐TiO2 NWs. [ABSTRACT FROM AUTHOR]

The carbon nanotubes (CNTs) supported amorphous Sb doped substoichiometric tin dulfide (Sb─SnSx) with a carbon coating (the C/Sb─SnSx@CNTs‐500) is reported to be an efficient anode material for K+ storage. The formation of the C/Sb─SnSx@CNTs‐500 is simply achieved through the thermally induced desulfurization of tin sulfide via a controlled annealing of the C/Sb─SnS2@CNTs at 500 °C. When used for the K+ storage, it can deliver stable reversible capacities of 406.5, 305.7, and 238.4 mAh g−1 at 0.1, 1.0, and 2.0 A g−1, respectively, and shows no capacity drops when potassiated/depotassiated at 1.0 and 2.0 A g−1 for >3000 and 2400 cycles, respectively. Even at 10, 20, and 30 A g−1, it can still deliver stable reversible capacities of 138.5, 85.1, and 73.8 mAh g−1, respectively. The unique structure, which combines the advantageous features of carbon integration/coating, metal doping, and desulfurization‐induced amorphous structure, is the main origin of the high performance of the C/Sb─SnSx@CNTs‐500. Specifically, the carbon integration/coating can increase the electric conductivity and stability of the C/Sb─SnSx@CNTs‐500. The density function theory calculation indicates that the Sb doping and the desulfurization can facilitate the potassiation and increase the electric conductivity of Sb─SnSx. Additionally, the desulfurization can increase the K+ diffusivity in Sb─SnSx. [ABSTRACT FROM AUTHOR]

The development of sodium‐ion battery (SIB) anodes is still hindered by their rapid capacity decay and poor rate capabilities. Although there have been some new materials that can be used to fabricate stable anodes, SIBs are still far from wide applications. Strategies like nanostructure construction and material modification have been used to prepare more robust SIB anodes. Among all the design strategies, the hollow structure design is a promising method in the development of advanced anode materials. In the past decade, research efforts have been devoted to modifying the synthetic route, the type of templates, and the interior structure of hollow structures with high capacity and stability. A brief introduction is made to the main material systems and classifications of hollow structural materials first. Then different morphologies of hollow structural materials for SIB anodes from the latest reports are discussed, including nanoboxes, nanospheres, yolk shells, nanotubes, and other more complex shapes. The most used templates for the synthesis of hollow structrual materials are covered and the perspectives are highlighted at the end. This review offers a comprehensive discussion of the synthesis of hollow structural materials for SIB anodes, which could be potentially of use to research areas involving hollow materials design for batteries. [ABSTRACT FROM AUTHOR]

Oxygen vacancy (OV)-rich solid-solution ruthenium manganese oxide nanowires (V-RuxMn1−xO2 NWs), synthesized by the hydrothermal reaction of metastable MnO2 nanosheets in the presence of RuCl3 with the use of CoCl2 as the OV producer, are reported to be efficient and stable catalysts for acidic oxygen evolution reaction (OER). They only need an overpotential of 200 mV to drive 10 mA cm−2 and show excellent durability for >600 h in 0.5 M H2SO4. Their mass activity is >35.9 times higher than that of commercial RuO2. The strong Ru–O–Mn bond interaction achieved by the solid solution structure and the OVs are the main origins of their high activity and excellent durability for the acidic OER. The Ru–O–Ru bonds are not favorable for the high catalytic activity of the V-RuxMn1−xO2 NWs. The DFT calculations indicate that both the strong Ru–O–Mn bond interaction and the OVs can decrease the energy barrier of the OER rate-determining step and suppress Ru demetallation, improving the catalytic activity and stability of the V-RuxMn1−xO2 NWs. A water electrolyzer with the V-RuxMn1−xO2 NWs exhibits a low voltage of 1.48 V to deliver 10 mA cm−2 and shows no obvious performance drop for >300 h at 10 mA cm−2, respectively. [ABSTRACT FROM AUTHOR]

Resonance Raman spectra and absolute differential Raman cross-sections have been measured for CdSe nanocrystals in both the wurtzite and zincblende crystal forms at four excitation wavelengths from 457.9 to 514.5 nm. The frequency and bandshape of the longitudinal optical (LO) phonon fundamental is essentially identical for both crystal forms at each excitation wavelength. The LO phonon overtone to fundamental intensity ratio appears to be slightly higher for the wurtzite form, which may suggest slightly stronger exciton-phonon coupling from the Fröhlich mechanism in the wurtzite form. The LO fundamental Raman cross-sections are very similar for both crystal forms at each excitation wavelength. © 2012 Elsevier B.V. All rights reserved.

The development of stable electrode materials with high specific capacities is of paramount importance for sodium-ion batteries (SIBs) to make them competitive with lithium-ion batteries (LIBs). This study reports the use of a Co-seed-mediated method for the synthesis of CNT-supported multiphase zero-valent Sb nanoparticles in the forms of Sb, CoSb, and CoSb2 with nitrogen-doped carbon coating (NC@CoSb/CNTs-400). The obtained NC@CoSb/CNTs-400 shows high capacities and excellent durability for sodium storage. It can exhibit high stable reversible capacities of 352.4 and 330.4 mA h g−1 at 0.1 and 1.0 A g−1, respectively, and deliver outstanding rate-capacities of 263.8 and 243.9 mA h g−1 at 5.0 and 10.0 A g−1, respectively. No obvious capacity drops are observed when it is sodiated/desodiated at 5.0 and 10.0 A g−1 for >10 000 cycles, respectively. Its superior performance arises from the unique structure. Specifically, the multiphase Sb NPs in the forms of Sb, CoSb, and CoSb2 increase the accessibility of Sb to sodium storage, improving the specific capacities of NC@CoSb/CNTs-400. The NC coating and CNT support increase the stability of NC@CoSb/CNTs-400, endowing it with excellent durability. [ABSTRACT FROM AUTHOR]