Carbon Dioxide-Assisted Fabrication of Highly Uniform Submicron-sized Colloidal Carbon Spheres via Hydrothermal Carbonization Using Soft Drink

An eco-friendly and economical method for the formation of highly uniform-sized carbon spheres by hydrothermal dehydration/condensation of a commercial carbonated beverage at 200 A degrees C is reported. Until now, the effect of an extra pressure which is built up by dissolved CO2 on the generation of carbon spheres under hydrothermal condition less than 250 A degrees C hasn't been demonstrated yet. In general, a complicated reactor is required to put overpressure on the autoclave vessel by adding inert gases, whereas the manipulation of a carbonated beverage including fructose and glucose molecules as precursors is favorable to design a simple experimental set-up and to investigate the effect of extra pressure on the growth of carbon spheres under mild hydrothermal condition. Herein, CO2 dissolved in the beverage accelerates the dehydration kinetics of the dissolved sugar molecules leading to production of homogeneous carbon spheres having a diameter less than 850 nm. In addition, the rough surface of these carbon spheres likely results from continuous Ostwald ripening of constituent microscopic carbon-containing spheres that are formed by subsequent polymerization of intermediate hydroxymethylfurfural molecules.X118sciescopu

Catalytic templating approaches for three-dimensional hollow carbon/graphene oxide nano-architectures

We report a catalytic templating method to synthesize well-controlled three-dimensional carbon nano-architectures. Depending on graphene oxide content, the morphology can be systematically tuned from layered composites to 3D hollow structures to microporous materials. The composites with high surface area and high porosity induce a significant enhancement to its capacitance at high current density.open112022sciescopu

Effect of annealing temperature on TiO2 nanorod films prepared by dc reactive magnetron sputtering for dye-sensitized solar cells

The anatase TiO2 nanorod films have been prepared on ITO coated glass substrates at room temperature by dc reactive magnetron sputtering technique. The nanorods are highly ordered and are perpendicular to the substrate. XRD measurements show that the anatase nanorods have a preferred orientation along the [110] direction. The prepared nanorods were annealed at different temperatures (200 ºC – 500 ºC) in air for 1 hour. The dye-sensitized solar cells (DSSC) have been made using the as-deposited and annealed TiO2 nanorods as working electrode. It has been found that annealing will improve the efficiency of the DSSC. An optimum conversion efficiency of 2.13%, at 100 mW/cm2 light intensity, has been achieved with TiO2 nanorods annealed at 300 ºC