Recently, there has been great interest in developing semiconductor photocatalysts with high activities for environmental applications, such as air purification and water disinfection. [1] The thoroughly studied conventional TiO 2 system displays excellent activities and stabilities. However, it requires UV light for effective photocatalysis, thus severely limiting its practical utility. It is highly desirable for the photocatalytic system to harness visible light, which can be obtained in high intensity under normal sunlight conditions. To develop visible-light-driven photocatalytic semiconductors, the following strategies can be adopted: phase and morphological control, doping, surface sensitization, composite materials. [2] Morphological control of nanostructured semiconducting metal oxides has attracted special interest due to their novel properties and potential applications in electronics, photonic devices, and photocatalytic media. [3] In particular, SnO 2 one-dimensional (1D) nanomaterials have been used as building blocks for nanoelectronics and have also been applied in chemical sensors due to their enhanced sur-face-to-volume ratio. [4] Although there have been considerable efforts toward the synthesis of SnO 2 1D nanomaterials, [5] the shape-specific synthesis of SnO 2 1D nanomaterials with small diameters has not been reported. Herein, we report the growth-direction-selective synthesis of soluble SnO 2 nanorods and bipods with small diameters (< 5 nm) based on the oleylamine-assisted hydrolysis of tin alkoxide in the presence of a high content of oleic acid (OA), which acts both as a solvent and a surfactant. We also report the unprecedented visible-light-driven photocatalytic properties of SnO 2 bipods.Soluble SnO 2 1D nanostructures were synthesized by a one-step synthetic method based on the starting materials SnA C H T U N G T R E N N U N G (OtBu) 4 , H 2 O, oleylamine, and OA. The structures of the products were examined by transmission electron microscopy (TEM). As shown in Figure 1 a, a rodlike morphology is evident when 15 equiv OA is employed, and the diameter of the nanorods is uniform throughout their length. Interestingly, V-shaped bipods were obtained when the amount of OA was increased to 75 equiv (Figure 1 b). Although, similar V-shaped SnO 2 bipods but with much larger diameters were previously prepared at 850 8C, [5] the low-temperature preparation of SnO 2 bipods has not been reported as yet.

Well-oriented ZnO nanorod arrays were successfully prepared using a seed growth method based on catalyst-free hydrothermal synthesis and characterized by field emission scanning electron microscopy, optical spectroscopy, photoelectrochemistry, and X-ray diffraction techniques. Compared to ZnO nanoparticles or randomly distributed ZnO nanorods, the well-oriented ZnO nanorod arrays exhibited significantly different electronic and photoelectrochemical properties. The generated photocurrent of the well-oriented ZnO nanorod array electrode was enhanced with several orders of magnitude higher intensities than that of the ZnO nanoparticle or the randomly distributed ZnO nanorod electrodes with the maximum wavelength of the photocurrent spectrum tunable from 345 to 385 nm. The photocatalytic activity of the well-oriented ZnO nanorod arrays, evaluated using the photodegradation of Rhodamine B as a probe reaction, was also significantly enhanced in comparison to that of ZnO nanoparticles or TiO2 P25 nanoparticles. The enhancement of the photocurrent and photocatalytic activity is suggested to arise from the tunable photoresponse that enhances the light harvesting and thereby generation of a larger number of photoinduced electron−hole pairs at active sites. Other possible causes include favorable electron transfer and electronic properties of the well-oriented ZnO nanorod arrays, for example, high densities of surface states and electron donor states as well as negative shift of the conduction band. The results are important for understanding the unique electronic and photoelectrochemical properties of well-oriented arrayed nanostructures and for designing novel arrayed nanostructures with advanced functionalities for photocatalytic and photoelectrochemical applications.

Mushrooms traditionally collected from forests and now more cultivated have recently become the products of the fifth-largest agricultural sector in China. It was estimated that more than 25 million farmers in China are currently engaged in the collection, cultivation processing and marketing of mushrooms. The total value of mushroom products amounted to 149 billion RMB Yuan (24 billion USD) in 2011. The raw materials have expanded from a few hardwoods to a variety of woods and increasing more into agricultural residues and wastes. The average annual growth rate has been over 10% over the past 30 years in China. This paper describes the rapid growth of mushroom cultivation and its contribution to food security and rural sustainable development. The roles of bio-innovation, technological dissemination, and marketing are also examined. Mushrooms could potentially be very important in future food supplies and in new dimensions of sustainable agriculture and forestry.