MnO(2) nanoflakes coated on carbon nanohorns (CNHs) has been synthesized via a facile solution method and evaluated as anode for lithium-ion batteries. By using CNHs as buffer carrier, MnO(2)/CNH composite displays an excellent capacity of 565 mA h/g measured at a high current density of 450 mA/g after 60 cylces.

eV), [1][2][3] remarkable absorption coefficient (≈10 5 cm −1 ), [4,5] excellent stability, and low-toxicity component. To promote the power conversion efficiency, many methods have been successfully applied to fabricate Sb 2 (S x ,Se 1-x ) 3 solar cells. For example, the rapid thermal evaporation (RTE) method [6] have been gathered many attentions for the fabrication of Sb 2 Se 3 solar cells. Recently, Tang and co-workers used a novel vapor transport deposition (VTD) way to refresh the recorded efficiency of Sb 2 Se 3 solar cell to 7.6%, [7] which has been made a great progress since Sb 2 Se 3 was successfully achieved a power conversion efficiency (PCE) of 0.03% in 2002. [8] On the other hand, Choi et al. have achieved a PCE of 7.5% [9] for Sb 2 S 3 by chemical bath deposition (CBD). Although the VTD and CBD methods have achieved impressive efficiency over 7%, a number of processing issues arise in these approaches. For example, VTD deposition processes are complex and expensive. While the nonvacuums CBD method also has weaknesses such as (i) the film prepared from CBD method is tend to be amorphous; [8,10] (ii) the Sb 2 S 3 film prepared by CBD method is antimony rich which results in a higher mean coordination number (MCN) than the stoichiometric Sb 2 S 3 . It will make it too rigid to flatten out after the annealing step; [11] (iii) the Sb 2 S 3 film prepared by CBD method inevitably includes impurities such as SbOCl, Sb 2 O 3 , and Sb 2 (SO 3 ) 3 . [12][13][14] Meanwhile, although the crystalline of the film fabricated by RTE or VTD is promising, the compactness of the absorber needs a further improvement. Thus, seeking for an effective and easy-handle nonvacuum approach to improve Sb 2 (S x ,Se 1-x ) 3 thin film solar cells is urgently needed.Since the hydrothermal method is a useful method in thin film preparation, the quality and homogeneity of the film deposited by this method is remarkable, which is expected to be able to solve the problem mentioned above and cut down the cost of fabrication. Liu et al. have taken this method to prepare the Sb 2 S 3 thin films, but there is no device reported. [15] In our previous work, double buffer layer was used to tune the band align and reduce recombination, which has achieved V oc as high as 792 mV based on hydrothermal derived Sb 2 (S x ,Se 1-x ) 3 solar cell. [16] But the thick buffer layer (60 nm TiO 2 + 60 nm CdS) inevitably increases the R s of device and decreases the transmittance as well, both of which will reduce J sc and PCE. Besides, the formation mechanism for Sb 2 S 3 thin films based Antimony sulfide-selenide Sb 2 (S,Se) 3 as a promising absorber material has drawn extensive attention owing to its rewarding photoelectric properties, low toxicity, and earth abundant components. Here, an available and highly effective method, in situ hydrothermal growth accompanied with postselenization, is successfully applied to fabricate Sb 2 (S,Se) 3 solar cells. The rationale for the preparation of Sb 2 S 3 precursors by the hydrothermal method is discussed, and ...

A major obstacle in realizing Na-ion batteries (NIBs) is the absence of suitable anode materials. Herein, we firstly report the anatase TiO2 mesocages constructed by crystallographically oriented nanoparticle subunits as a high performance anode for NIBs. The mesocages with tunable microstructures, high surface area (204 m2 g−1) and uniform mesoporous structure were firstly prepared by a general synthesis method under the assist of sodium dodecyl sulfate (SDS). It’s notable that the TiO2 mesocages exhibit a large reversible capacity and good rate capability. A stable capacity of 93 mAhg−1 can be retained after 500 cycles at 10 C in the range of 0.01–2.5 V, indicating high rate performance and good cycling stability. This could be due to the uniform architecture of iso-oriented mesocage structure with few grain boundaries and nanoporous nature, allowing fast electron and ion transport, and providing more active sites as well as freedom for volume change during Na-ion insertion. CV measurements demonstrate that the sodium-ion storage process of anatase mesocages is mainly controlled by pseudocapacitive behavior, which is different from the lithium-ion storage and further facilitates the high rate capability.

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Three-dimensional temperature (T)–pressure (P)–composition (X) phase diagrams of binary carbon-hydrogen (C–H) and carbon-oxygen (C–O) systems for activated low pressure diamond growth have been calculated. Based on an approximation of linear combination between C–H and C–O systems, a projective ternary carbonhydrogen-oxygen (C–H–O) phase diagram has also been obtained. There is always a diamond growth region in each of these phase diagrams. Once a supply of external activating energy stops, the diamond growth region will not exist. Nearly all of the reliable experimental data reported in the literature drop into the possible diamond growth region of the calculated projective ternary C–H–O phase diagram under the conditions of 0.01–100 kPa and above 700 K.

Employing first-principles calculations, we investigate efficiency of spin injection from a ferromagnetic (FM) electrode (Ni) into graphene and possible enhancement by using a barrier between the electrode and graphene. Three types of barriers, h-BN, Cu(111), and graphite, of various thickness (0-3 layers) are considered and the electrically biased conductance of the Ni/Barrier/Graphene junction are calculated. It is found that the minority spin transport channel of graphene can be strongly suppressed by the insulating h-BN barrier, resulting in a high spin injection efficiency. On the other hand, the calculated spin injection efficiencies of Ni/Cu/Graphene and Ni/Graphite/Graphene junctions are low, due to the spin conductance mismatch. Further examination on the electronic structure of the system reveals that the high spin injection efficiency in the presence of a tunnel barrier is due to its asymmetric effects on the two spin states of graphene.