thermodynamic equilibrium potential, as shown in Figure 1. The HER process involves electro chemical H + adsorption and electrochemical/chemical desorption of H 2 , which is a two-electron transport process to generate a single H 2 molecule. By contrast, OER undergoes a four-electron transport coupled with the breaking of the OH bond, and the formation of the OO bond; therefore, for a kinetically hindered process, a high potential is needed to overcome the kinetic energy barriers. [12] To date, the OER remains a bottleneck in water splitting. Therefore, enormous efforts have been devoted to design and discover novel OER catalysts to satisfy the economic production of hydrogen from water splitting.Thus far, the benchmarks of OER catalysts in acidic solution are RuO 2 and IrO 2 , which are located on top of the volcanoplot, and express a relatively low overpotential (η), high current density, small Tafel slope, and high durability. [13,14] However, the wide utilization of RuO 2 or IrO 2 is hindered by high cost and insufficient reserves in the earth. Moreover, the aforementioned noble metal oxides are not the best OER electrocatalysts under alkaline conditions anymore. Their OER performances have been exceeded by several first-row transition metal based compounds (FTMCs). [15][16][17][18][19][20][21] Therefore, considerable attention has been focused on cost-effective alternatives that feature high electrocatalytic activity and life span. However, a relatively high overpotential (>300 mV) is still required by these nonprecious catalysts to reach a current density of 10 mA cm −2 , a widely used figure of merit that is equivalent to 12% solar-to-hydrogen efficiency. Thus, improving OER performance based on FTMCs is of great significance.Previous discoveries demonstrated that elemental doping is effective to boost the performance of FTMCs, given that the electronic structure of the catalysts can be tuned by dopants. [12,15] A well-known example is iron-doped nickel compounds, with trace amounts of iron-doped nickel hydroxides possibly enhancing the catalytic activity of OER significantly. [21][22][23] Thus, considerable efforts have been focused on optimizing elemental doping species and concentration and identifying the active sites of the catalysts. In addition to elemental doping, several novel and advantageous strategies have been developed Owing to its abundance, high gravimetric energy density, and environmental friendliness, hydrogen is a promising renewable energy to replace fossil fuels. One of the most prominent routes toward hydrogen acquisition is water splitting, which is currently bottlenecked by the sluggish kinetics of oxygen evolution reaction (OER). Numerous of electrocatalysts have been developed in the past decades to accelerate the OER process. Up to now, the first-row transition metal based compounds are in pole position under alkaline conditions, which have become subjects of extensive studies. Recently, significant advances in providing compelling catalytic performance as well as exploring t...

Highly hierarchical platelike FeWO(4) microcrystals have been synthesized by a simple solvothermal route using FeCl(3) x 6 H(2)O and Na(2)WO(4) x 2 H(2)O as precursors, where ethylene glycol (EG) plays an important role as a capping agent in directing growth and self-assembly of such unique structures. In addition, a certain amount of CH(3)COONa (NaAc) was necessary for the formation of such unique FeWO(4) microstructures. The photocatalytic property of as-synthesized hierarchical FeWO(4) microcrystals has been first studied, which shows excellent photocatalytic activity for the degradation of rhodamine B (RhB) under UV and visible light irradiation (modeling sunlight). Moreover, magnetic measurement indicates that hexangular FeWO(4) platelike microcrystals show a small ferromagnetic ordering at low temperature because of spin-canting of antiferromagnetic materials and surface spins of FeWO(4) nanoparticles.

A simple solvothermal route in a binary solution of triethylenetetramine (TETA) and deionized water (DIW) has been used to synthesize hierarchical hollow Co(9)S(8) microspheres with high surface area (80.38 m(2) g(-1)). An appropriate volume ratio of TETA:DIW has been found to be essential for the formation of hollow Co(9)S(8) microspheres. The magnetic study indicated that the Co(9)S(8) hollow microspheres are paramagnetic at high temperature and antiferromagnetic at low temperature. The oxygen reduction reaction experiments demonstrated that the onset potential of the Co(9)S(8) sample is 0.88 V, which is comparable to the value predicted for Co(9)S(8) (0.74 V) from the theoretical simulation. The discharge capability of Co(9)S(8) hollow microspheres as cathode materials for lithium ion batteries and their electrocatalytic activity for the oxygen reduction reaction (ORR) have been studied.

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Three-dimensional (3D) urchin-like MnWO4 microspheres with a diameter of ca. 1−1.2 μm assembled by nanorods with a length of 240 nm and an aspect ratio of ca. 9 have been fabricated by a cationic surfactant cetyltrimethyl ammonium bromide (CTAB) assisted hydrothermal method. The result demonstrated that CTAB played an important role as a soft template in directing growth and self-assembly of urchin-like MnWO4 microspheres, and suitable pH values and reaction temperature are also essential for the formation of urchin-like microspheres. Magnetic measurement indicates that urchin-like MnWO4 microspheres show a weak ferromagnetic ordering at low temperature due to spin-canting and surface spins of microspheres, while much shorter MnWO4 nanorods show antiferromagnetism at low temperature.

Osteosarcoma is a primary malignant bone tumor that has a poor prognosis due to local recurrence, metastasis, and chemotherapy resistance. Therefore, there is an urgent need to develop novel potential therapeutic targets for osteosarcoma. Enhancer of zeste homologue 2 (EZH2) is a member of the polycomb group of proteins, which has important functions in epigenetic silencing and cell cycle regulation. Overexpression of EZH2 has been found in several malignancies, however, its expression and the role of EZH2 in osteosarcoma is largely unknown. In this study, we examined EZH2 expression by immunohistochemistry in a large series of osteosarcoma tissues in association with tumor characteristics and patient outcomes. EZH2 expression was also analyzed in a microarray dataset of osteosarcoma. Results showed that higher expression of EZH2 was significantly associated with more aggressive tumor behavior and poor patient outcomes of osteosarcoma. We subsequently investigated the functional and therapeutic relevance of EZH2 as a target in osteosarcoma. Immunohistochemical analysis indicated that EZH2 expression was significantly associated with more aggressive tumor behavior and poorer patient outcomes of osteosarcoma. EZH2 silencing by siRNA inhibited osteosarcoma cell growth, proliferation, migration, and invasion. Moreover, suppression of EZH2 attenuated cancer stem cell functions. Similar results were observed in osteosarcoma cells treated with EZH2 specific inhibitor 3-deazaneplanocin A (DZNep), which exhausted cellular levels of EZH2. These results suggest that EZH2 is critical for the growth and metastasis of osteosarcoma, and an epigenetic therapy that pharmacologically targets EZH2 via specific inhibitors may constitute a novel approach to the treatment of osteosarcoma.

The visible-light-driven photocatalytic activities of graphene-semiconductor catalysts have recently been demonstrated, however, the transfer pathway of photogenerated carriers especially where the role of graphene still remains controversial. Here we report graphene-SnO2 aerosol nanocomposites that exhibit more superior dye adsorption capacity and photocatalytic efficiency compared with pure SnO2 quantum dots, P25 TiO2, and pure graphene aerosol under the visible light. This study examines the origin of the visible-light-driven photocatalysis, which for the first time links to the synergistic effect of the cophotosensitization of the dye and graphene to SnO2. We hope this concept and corresponding mechanism of cophotosensitization could provide an original understanding for the photocatalytic reaction process at the level of carrier transfer pathway as well as a brand new approach to design novel and versatile graphene-based composites for solar energy conversion.

A solvothermal reaction in a mixed solvent made of triethylenetetriamine (TETA) and deionized water (DIW) results in the formation of well-defined [Fe 18 S 25 ](TETAH) 14 nanoribbons. A suitable volume ratio of TETA and DIW is essential for the formation of elegant [Fe 18 S 25 ](TETAH) 14 nanoribbons. The [Fe 18 S 25 ](TETAH) 14 nanoribbons can act as efficient precursors for production of either Fe 7 S 8 nanowires or porous R-Fe 2 O 3 nanorods by thermal decomposition of [Fe 18 S 25 ](TETAH) 14 in an argon or air atmosphere. The present study demonstrates that the combination of small molecule polyamine with magnetic semiconductor makes it possible to obtain new hybrid nanostructured materials. The thermal decomposition of this new hybrid material is a powerful tool as a unique pathway for controlled synthesis of transition metal chacolgenide nanomaterials and porous transition metal oxides.