Trends in renewable energy production employing biomass-based biochar.

Tremendous population growth and industrialization have increased energy consumption unprecedentedly. The depletion of fossil-based energy supplies necessitates the exploration of solar, geothermal, wind, hydrogen, biodiesel, etc. as a clean and renewable energy source. Most of these energy sources are intermittent, while bioelectricity, biodiesel, and biohydrogen can be produced using abundantly available organic wastes regularly. The production of various energy resources requires materials that are costly and affect the applicability at a large scale. Biomass-derived materials (biochar) are getting attention in the field of bioenergy due to their simple method of synthesis, high surface area, porosity, and availability of functional groups for easy modification. Biochar synthesis using various techniques is discussed and their use as an electrode (anodic/cathodic) in a microbial fuel cell (MFC), catalysts in transesterification, and anaerobic digestion for energy production are reviewed. Renewable energy production using biochar would be a sustainable approach to create an energy secure world.

Eosin-Y sensitized core-shell TiO2-ZnO nano-structured photoanodes for dye-sensitized solar cell applications.

In the current investigation, TiO2 and TiO2-ZnO (core-shell) spherical nanoparticles were synthesized by simple combined hydrolysis and refluxing method. A TiO2 core nanomaterial on the shell material of ZnO was synthesized by utilizing variable ratios of ZnO. The structural characterization of TiO2-ZnO core/shell nanoparticles were done by XRD analysis. The spherical structured morphology of the TiO2-ZnO has been confirmed through field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) studies. The UV-visible spectra of TiO2-ZnO nanostructures were also compared with the pristine TiO2 to investigate the shift of wavelength. The TiO2-ZnO core/shell nanoparticles at the interface efficiently collect the photogenarated electrons from ZnO and also ZnO act a barrier for reduced charge recombination of electrolyte and dye-nanoparticles interface. This combination improved the light absorption which induced the charge transfer ability and dye loading capacity of core-shell nanoparticles. An enhancement in the short circuit current (Jsc) from 1.67 mA/cm2 to 2.1 mA/cm2 has been observed for TiO2-ZnObased photoanode (with platinum free counter electrode), promises an improvement in the energy conversion efficiency by 57% in comparison with that of the DSSCs based on the pristine TiO2. Henceforth, TiO2-ZnO photoelectrode in ZnO will effectively act as barrier at the interface of TiO2-ZnO and TiO2, ensuring the potential for DSSC application.

Laterally-stacked, solution-processed organic microcrystal with ambipolar charge transport behavior.

We report the formation of laterally stacked ambipolar crystal wire for high-mobility organic field-effect transistors (OFETs), along with a simple logic circuit through a solution process. A soluble pentacene derivative, 6,13-bis(triisopropylsilylethynyl)pentacene (Tips-pentacene), and N,N'-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) were used as p-type and n-type organic semiconductors, respectively. The laterally stacked ambipolar crystal wire is made up of Tips-pentacene and PTCDI-C8 crystals in a structure of Tips-pentacene/PTCDI-C8/Tips-pentacene (TPT). The inner part of the crystal is made up of PTCDI-C8, and Tips-pentacene is present on both sides. These TPT crystals exhibit typical ambipolar charge transport behavior in organic electronic devices, which show very balanced hole and electron mobility as high as 0.23 cm(2)/V·s and 0.13 cm(2)/V·s, respectively. Static and dynamic operational stability of the device is investigated by measuring the device performance as a function of storage time and applying voltage pulse, respectively, and it shows good air stability. In addition, a simple logic circuit based on the TPT crystal wire has been fabricated, and the static and dynamic performance has been evaluated. The results indicate that the TPT crystals are potentially useful for miniaturized organic electronic devices.

Solution-grown single-crystalline microwires of a molecular semiconductor with improved charge transport properties.

Preparation and structural analysis of highly ordered single crystalline wires of a diketopyrrolopyrrole (DPP) molecular semiconductor grown through a solution process are reported, and the static/dynamic electrical response of an organic electronic device using the DPP semiconductor has been analyzed.