Shu-Hong Yu

Large scale synthesis of uniform CuS nanotubes in ethylene glycol by a sacrificial templating method under mild conditions

Uniform CuS nanotubes of 30–90 nm in inner diameter and 20–50 nm in thickness, can be synthesized in large quantities by a facile solution reaction at 80 °C in ethylene glycol using Cu nanowires as sacrificial templates and choosing suitable sulfur sources for the sulfuration reaction, where suitable sulfur sources and solvent played crucial roles in the formation of well-defined CuS nanotubes. The results demonstrated that suitable sulfur sources such as thiourea and thiacetamide which release ionic sulfur rather than molecular sulfur at their decomposition temperature are favorable for the formation of CuS nanotubes, in contrast to sulfur powders. Further treatment of the product at higher temperature (140 °C) can improve the crystallinity but results in a slight shrinking of the nanotubes toward the inner side. In addition, the similar reaction in water media cannot produce such nanotubes. The shape evolution process and the formation mechanism of CuS nanotubes as well as the thermal stability of these nanotubes were studied.

Synthesis of copper/cross-linked poly(vinyl alcohol)(PVA) nanocables via a simple hydrothermal route

Cross-linking reaction of poly(vinyl alcohol) n (PVA) can be initiated in the presence of copper ions, resulting in the formation of copper@cross-linked PVA nanocables by a one-step hydrothermal approach. In contrast to our previous findings in the case of silver ions, metal ions with high valency are more difficult to reduce during the cross-linking reactions under hydrothermal conditions. The variation of pH value during the reaction has significant effects on the quality of the product. Copper@cross-linked PVA nanocables with a diameter of 0.5–1 µm and length up to 100 µm can be obtained at 200 °C, accompanying the presence of some cross-linked PVA aggregates with near spherical shape and irregular shape. The pH value, reaction temperature, and reaction time play key roles in the formation of such nanocables. The results demonstrated that the cross-linking reaction in the presence of different metal ions has different reaction rates, which determine the uniformity of the product and the quality of the cable-like core–shell structures.

Large scale synthesis of uniform silver@carbon rich composite (carbon and cross-linked PVA) sub-microcables by a facile green chemistry carbonization approach

A facile green chemistry carbonization method has been discovered for the synthesis of uniform silver@carbon rich composite (carbon and cross-linked polyvinyl alcohol) core-shell sub-microcables in large quantities, where the carbon sources such as glucose-based saccharides have played important roles in the formation of these novel sub-microcables.

Synthesis of uniform carbon @ silica nanocables and luminescent silica nanotubes with well controlled inner diameters

Uniform carbon@silica nanocables and silica nanotubes with well-controlled inner diameters can be synthesized in an easy way by a sacrificial templating method. This was performed using carbon nanofibres as hard templates that were synthesized previously by a hydrothermal carbonization process. Silica nanotubes with well-controlled inner diameters were synthesized from carbon@silica core–shell nanostructures by removal of the core carbon component. The inner diameters of the as-prepared silica nanotubes can be well controlled from several nanometres to hundreds of nanometres by adjusting the diameters of the carbon nanofibres. The silica nanotubes synthesized by this method display strong photoluminescence in ultraviolet at room temperature. Such uniform silica nanotubes might find potential applications in many fields such as encapsulation, catalysis, chemical/biological separation, and sensing.