Redox Flow Capacitive Deionization in a Mixed Electrode Solvent of Water and Ethanol

In the redox flow electrode capacitive deionization (FCDI), the solubility of redox electrolyte and flowability of carbon slurry have great influence on the salt removal rate and energy consumption. In this work, a mixed solvent electrolyte is proposed in FCDI, which consists of iodide/triiodide redox couples and carbon slurry in the mixed solvent of water and ethanol (1:1). At the current density of 5 mA cm-2, the salt removal rate can reach up to 2.72 μg cm-2 s-1 in a mixed solvent, which is much higher than 1.74 μg cm-2 s-1 in aqueous solution and 2.37 μg cm-2 s-1 in the ethanol solution. This may be owing to the fast transport of ions during redox reaction in organic solvent and the excellent flowability of carbon slurry in the aqueous condition, which can provide more reaction sites for iodide/triiodide redox reaction and faster electron transportation. This unique FCDI with organic and aqueous mixed solvent electrolyte will provide a new perspective for the development of redox flow electrochemical desalination.

Crystal Growth and Design of Disk/Filament ZnO-Decorated 1D TiO2 Composite Ceramics for Photoexcited Device Applications

Disk- and filament-like ZnO crystals were decorated on one-dimensional TiO2 nanostructures (TiO2–ZnO) through various integrated physical and chemical synthesis methods. The morphology of the ZnO crystals on TiO2 varied with the chemical synthesis method used. ZnO nanodisks decorated with TiO2 nanorods (TiO2–ZnO–C) were synthesized using the chemical bath deposition method, and ZnO filament-like crystals decorated with TiO2 nanorods (TiO2–ZnO–H) were synthesized through the hydrothermal method. Compared with the pristine TiO2 nanorods, the as-synthesized TiO2–ZnO composites exhibited enhanced photophysiochemical performance. Furthermore, because of their fast electron transportation and abundant surface active sites, the ZnO nanodisks in the TiO2–ZnO–C composite exhibited a higher photoactivity than those in the TiO2–ZnO–H composite. The morphology and crystal quality of the ZnO decoration layer were manipulated using different synthesis methods to realize disk- or filament-like ZnO-decorated TiO2 composites with various photoactive performance levels.

Doping mechanism directed graphene applications for energy conversion and storage

Due to ultrabroadband optical absorption, large theoretical surface area, outstanding thermal conductivity and massless electron transportation, graphene has been considered as a prospective candidate in the applications of energy conversion...

Simulation of Ion Current in Oxyfuel Flame Subject to an Electric Field

This paper presents a computational model to study ion and electron transportation and current-voltage characteristics inside a methane-oxygen flame. A commercial software is used to develop the model by splitting the simulation into the combustion and electrochemical transportation parts. A laboratory experiment is used to compare the results from the model. The initial and boundary conditions represented in the model are similar to the experimental conditions in the laboratory experiment. In the combustion part, the general GRI3.0 mechanism plus three additional ionization reactions are applied and results are then used as input into the electrochemical transportation part. A particular inspection line is created to analyze the results of the electrochemical transportation part. Ion, electron number density, and current density are studied along the interval from −40V to 40V electric potential. The ions are heavier and more difficult to move than electrons. The results show that at both torch and work surfaces charged sheaths are formed and cause three different regions of current-voltage relations.

The theoretical investigation of the opto-electronic properties of designed molecules having 2-(2-Methylene-3-oxo-indane-1-ylidene)malononitrile as end-capped acceptors

Five acceptor-donor-acceptor molecules having different core units with 2-(2-Methylene-3-oxo-indane-1-ylidene)malononitrile as end capped terminal acceptor unit were designed. The ground state geometries and electronic properties were calculated by using density functional theory (DFT) at MPW1PW91/6-31G(d,p) level of theory. The absorption spectra were computed by using time dependent DFT at MPW1PW91/6-31G(d,p) level of theory. The designed molecules have broad absorption range in visible region. M3 shows relatively lower band gap so that having high light harvesting efficiency (LHE). The molecules consider as better hole blocking materials in term of high ionization potentials. The reorganization energies calculation of M1, M2 and M4 manifests that these molecules are the optimal candidate for electron transportation. High value of Voc has been observed for molecules which would favorably contribute in power conversion efficiency. M1, M2, M4 and M5 are more stable in terms of absolute hardness and electrostatic potential surfaces. All molecules show good opto-electronic properties in the aspect of their use in photovoltaic application.

The theoretical investigation of the opto-electronic properties of designed molecules having 2-(2-Methylene-3-oxo-indane-1-ylidene)malononitrile as end-capped acceptors

Five acceptor-donor-acceptor molecules having different core units with 2-(2-Methylene-3-oxo-indane-1-ylidene)malononitrile as end capped terminal acceptor unit were designed. The ground state geometries and electronic properties were calculated by using density functional theory (DFT) at MPW1PW91/6-31G(d,p) level of theory. The absorption spectra were computed by using time dependent DFT at MPW1PW91/6-31G(d,p) level of theory. The designed molecules have broad absorption range in visible region. M3 shows relatively lower band gap so that having high light harvesting efficiency (LHE). The molecules consider as better hole blocking materials in term of high ionization potentials. The reorganization energies calculation of M1, M2 and M4 manifests that these molecules are the optimal candidate for electron transportation. High value of Voc has been observed for molecules which would favorably contribute in power conversion efficiency. M1, M2, M4 and M5 are more stable in terms of absolute hardness and electrostatic potential surfaces. All molecules show good opto-electronic properties in the aspect of their use in photovoltaic application.

Effects of red and blue light on leaf anatomy, CO2 assimilation, and the photosynthetic electron transport capacity of sweet pepper (Capsicum annuum L.) seedlings

Background: The red (R) and blue (B) light wavelengths are known to influence many plant physiological processes during growth and development, particularly photosynthesis. To understand how R and B light influences plant photomorphogenesis and photosynthesis, we investigated changes in leaf anatomy, chlorophyll fluorescence and photosynthetic parameters, and ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) and Calvin cycle-related enzymes expression and their activities in sweet pepper (Capsicum annuum L.) seedlings exposed to four light qualities: monochromatic white (W, control), R, B and mixed R and B (RB) light with the same photosynthetic photon flux density (PPFD) of 300 μmol/m2·s. Results: The results revealed that seedlings grown under R light had lower biomass accumulation, CO2 assimilation and photosystem II (PSII) electron transportation compared to plants grown under other treatments. These changes are probably due to inactivation of the photosystem (PS). Biomass accumulation and CO2 assimilation were significantly enriched in B- and RB-grown plants, especially the latter treatment. Their leaves were also thicker, and photosynthetic electron transport capacity, as well as the photosynthetic rate were enhanced. The up-regulation of the expression and activities of Rubisco, fructose-1, 6-bisphosphatase (FBPase) and glyceraldehyde-phosphate dehydrogenase (GAPDH), which involved in the Calvin cycle and are probably the main enzymatic factors contributing to RuBP (ribulose-1, 5-bisphosphate) synthesis, were also increased. Conclusions: Mixed R and B light altered plant photomorphogenesis and photosynthesis, mainly through its effects on leaf anatomy, photosynthetic electron transportation and the expression and activities of key Calvin cycle enzymes.