We report here on the synthesis and photophysical/electrochemical properties of a series of novel triphenylamine (TPA)-based organic dyes (TPAR1, TPAR2, TPAR4, and TPAR5) as well as their application in dye-sensitized nanocrystalline TiO2 solar cells (DSCs). In the four designed dyes, the TPA group and the rhodanine-3-acetic acid take the role of the basic electron donor unit and the electron acceptor, respectively. It was found that introduction of a CH2CH− group into the TPA unit exhibited better photovoltaic performance due to the increase of the electron-density donor moiety and that introduction of a methine (−CHCH−) unit to the π bridge resulted in a red-shift and broadening of the absorption spectrum due to expansion of the π-conjugation system. Density functional theory (DFT) calculation indicated that the electron distribution moved from the donor unit to the electron acceptor under light irradiation, which means efficient intramolecular charge transfer. In particular, the DSCs based on TPAR4 showed the best photovoltaic performance:  a maximum monochromatic incident photon-to-current conversion efficiency (IPCE) of 81%, a short-circuit photocurrent density (J sc) of 18.2 mA cm-2, an open-circuit photovoltage (V oc) of 563 mV, and a fill factor (ff) of 0.61, corresponding to an overall conversion efficiency of 5.84% under AM 1.5 irradiation (100 mW cm-2). This work suggests that the molecular-designed triphenylamine dyes are promising in the application of DSCs.

A series of new conjugated metal-free organic dyes (TC1, TC2, TC3, and TC4) comprising triphenylamine (TPA) moieties as the electron donor and cyanoacetic acid moieties as the electron acceptor/anchoring groups were designed at the molecular level and developed for the use in dye-sensitized solar cells (DSCs). Quantum chemical calculations have been performed to gain insight into structural, electronic, and optical properties of the as-synthesized sensitizers. The time-dependent density functional theory calculations allowed assignment of the experimental spectroscopic data. It is found that the photovoltaic performance of the DSCs with the as-synthesized dyes can be improved by enhancing the electron-donor ability and extending the π-conjugated bridge of the dyes. In particular, the DSCs based on 2-cyano-5-(4-(phenyl(4-vinylphenyl)amino)phenyl) penta-2,4-dienoic acid dye ( TC4) showed an open circuit voltage of 652 mV, a short circuit photocurrent density of 11.5 mA cm -2 , and a fill factor of 0.64, corresponding to an overall light to electricity conversion efficiency of 4.82% under AM 1.5 irradiation (100 mW cm -2 ). This result reveals that efficient electron injection from the excited sensitizer to the conduction band of titania film occurs, owing to the more delocalizing electrons of the bridge and donor part of the dyes.

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Higher capacity rechargeable batteries can be constructed by using mesoscale nickel hydroxide tubes as the positive‐electrode material. The tubes were prepared by deposition of nickel ions and aqueous ammonia in an anodic alumina membrane as the template. The picture shows a high‐resolution TEM image of the tubes.

Li(Na)-CO2 batteries are attracting significant research attention due to contemporary energy and environmental issues. Li(Na)-CO2 batteries make possible the utilization of CO2 and open up a new avenue for energy conver-sion and storage. Research on this system is currently in its infancy, and its development is still faced with many challenges in terms of high charge potential, weak rate capability, and poor cyclability. Moreover, the reaction mechanism in the battery is still unclear and hard to determine, due to the generation of carbon along with metal carbonates on the cathode. In this review, the authors present the fundamentals and the latest progress related to Li(Na)-CO2 research. Detailed discussions are provided on the electrochemical reactions on cathode, cathode materials, and electrolytes. Current challenges and future perspectives on Li(Na)-CO2 batteries are also proposed Disciplines Engineering | Physical Sciences and Mathematics Publication DetailsCai, F., Hu, Z. & Chou, S. (2018 [17][18][19][20][21][22][23][24][25][26][27][28] As a new battery technology, metal-air batteries still face a number of problems, such as poor cycling performance, decomposition of electrolyte, high overpotentials etc. [29][30][31] It is well known that metal-air batteries with an open cell structure can generate power by the electrochemical reaction between metal and oxygen from the atmosphere. Using ambient air as the cathode for metal-air batteries, however, brings even more problematic molecules into the battery system. For example, moisture and CO 2 from the air easily react with the metal and discharge products to form insulating metal hydroxides and metal carbonates at the cathode, which can induce low energy efficiency and poor cycling stability. [32] Thus, most metal-air batteries in laboratories today run in a pure oxygen environment instead of ambient air.Although the concentration of CO 2 is low in ambient air (only 0.03 vol%), [33] CO 2 is known to be more soluble in organic electrolytes than O 2 (≈50 times higher than O 2 ), [34] resulting in the high possibility of CO 2 participation in battery reactions. Considering the influence of CO 2 on the operation of metalair batteries, researchers have focused on metal-CO 2 batteries that utilize an O 2 /CO 2 mixture or pure CO 2 as the reactant gas in the cathode, providing us with a new platform for electrical energy generation and CO 2 conversion and utilization. [35][36][37] At present, Li(Na)-CO 2 batteries have attracted most attention in relation to the development of primary metal-O 2 /CO 2 batteries to achieve rechargeable metal-CO 2 batteries.[38-50] The Li(Na)-CO 2 battery exhibits a high theoretical energy density of 1876 Wh kg −1 (1.13 kWh kg −1 for Na) based on the reaction of 4Li(Na) + 3CO 2 ↔ 2Li(Na) 2 CO 3 + C. [36,44] The operation of a rechargeable Li(Na)-CO 2 battery, however, is faced with the critical challenges of the poor round-trip efficiency and the decomposition of electrolyte caused by high charge overpotential, as well as o...

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Porous acetylene-black (AB) spheres were used as the cathode materials of dye-sensitized solar cells (DSC), showing low-cost, high electrochemical activity and energy-conversion efficiency (5.76%), indicating the potential replacement of noble-metal Pt in the cathode of DSC.