Surface Roughness: A Crucial Factor To Robust Electric Double Layer Capacitors.

Electric double layer capacitors (EDLCs) usually show high rate performance and long cycling spans but inferior specific capacitance, which are mainly created by restriction of the charge storage mechanism. To improve the capacitive performance, traditional methods include enlarging surface area, optimizing porous structures, and readjusting functional groups through heteroatom doping to electrode materials. Besides that, another promising approach is suggested, which is to enhance surface roughness of the electrode materials for ion storage and transport. To prove this view, two porous carbon materials were fabricated by activation-calcination methods, which allowed the materials to have identical surface area, porous structures, and surface composition but the surface roughness. Further electrochemical measurements exhibited that the optimal sample with higher roughness has remarkable specific capacitance (up to 562 F g-1), and the increment rate is more than 50% when compared with contrast sample (367 F g-1). Therefore, optimization of the surface roughness of electrode materials is another efficient route to make robust EDLCs.

Triboelectric Nanogenerator Powered Electrochemical Degradation of Organic Pollutant Using Pt-Free Carbon Materials.

Carbon electrode materials are fabricated from bean curd to replace costly Pt-based electrodes to degrade methyl red (MR) as self-driven by a multilayer linkage triboelectric nanogenerator (ML-TENG). With the sponge as the buffer layer and precharge injection, the peak open-circuit voltage, Voc, short-circuit current, Isc, and maximum power density of the ML-TENG can reach and remain stable at 1300 V, 1.2 mA, and 7.4 W m-2 (load resistance = 500 KΩ), respectively. Using the electric power generated by such an updated TENG, highly toxic and carcinogenic MR can be indirectly degraded to CO2 through an oxidation process induced by active chlorine produced at the as-obtained carbon-based electrode interface. Such an electrochemical degradation mechanism is proposed based on the cyclic voltammogram, gas chromatograph-mass spectrometer, and mass spectrometer. With compelling features of the TENG and carbon materials, such as sustainable energy, high and stable output performance, cost savings, and high degradation efficiency, this work pioneers the marriage of the TENG with carbon-based materials to self-power electrochemical degradation of organic pollutants for environmental protection.

Self-Powered Electrochemical Oxidation of 4-Aminoazobenzene Driven by a Triboelectric Nanogenerator.

A rotary disc-structured triboelectric nanogenerator (rd-TENG) on the basis of free-standing electrification has been designed, where the aluminum composite panel has not been tailored to the stator becauseit is commercially available and cost-effective, has good electronic conductivity, and is easily processed. With the rotating speed increasing from 200 to 1000 rpm, the short-circuit current (Isc) is sharply enhanced from 50 µA to 200 µA, while the measured open-circuit voltage (Voc) and transferred charge (Qtr) almost keep constant, 600 V and 0.4 µC, respectively. The matched load for the rd-TENG at a rotating speed of 600 rpm is 2.7 MΩ, generating a maximum power of 19.75 mW, which corresponds to a maximum power density of 2.28 W m-2. Using the electric power generated by such a rd-TENG, highly toxic and carcinogenic 4-aminoazobenzene can be selectively treated to produce CO2 or an oligomer via reasonably controlling electrochemical oxidation potentials. The underlying mechanism is tentatively proposed based on the cyclic voltammogram, gas chromatograph-mass spectrometer, electrochemical impedance spectroscopy, and UV-vis spectra. Here the electrochemical degradation in a single-compartment cell is more valid, preferable, and feasible. The output Voc and rectified current of rd-TENG guarantee its extensive application to self-power electrochemical degradation of other azo compounds, i.e., 2-(4-dimethylaminophenylazo) benzoic acid, to CO2. This work suggests that rd-TENG, sustainable energy, can be feasibly designed to self-power a practical electrochemical treatment of dyeing wastewater by harvesting vibration energy.

Self-Powered Electrochemistry for the Oxidation of Organic Molecules by a Cross-Linked Triboelectric Nanogenerator.

A cross-linked triboelectric nanogenerator with high performance is designed for the first time, which harvests vibrational energy to self-power the electrochemical oxidation of organic molecules. This system lays the groundwork for applications to an environmentally friendly production of important organic molecules and the waste treatment of organic pollutants.

Peanut-Shell-like Porous Carbon from Nitrogen-Containing Poly-N-phenylethanolamine for High-Performance Supercapacitor.

An efficient soft-template method is proposed for the synthesis of peanut shell-like porous carbon as high-performance supercapacitor electrode materials. The procedure is based on the pyrolysis and chemical activation processes using N-phenylethanolamine as precursor and KOH as activation agent. In a three-electrode system, the resultant carbon material has a specific capacitance of 356 F g(-1) at 1 A g(-1) and a good stability over 1000 cycles. Besides, at a high current density of 30 A g(-1), it has a specific capacitance of 249 F g(-1) and maintains 96% after 10,000 cycles. In two-electrode cell configuration, it delivers about 21.53 Wh kg(-1) at a current density of 20 A g(-1), which is about 7 times higher than the commercial device (<3 Wh kg(-1)). Both high specific capacitance and excellent cycling stabilities guarantee its utilization in supercapacitors.

[Study on physiological characteristics of seed germination of Ephedra sinica].

OBJECTIVE: To study the characteristics of the Ephedra sinica seed germination, to provide a basis for its cultivation. METHODS: The seed germination inhibitive substances were studied by water washing method; the seed vigor was determined by TTC method and red ink method, the influence of growth substances to seed germination was studied by agar medium cultivation, and the influence of different sand burying depth on seed germination was studied by sand medium cultivation. RESULTS: The seed germination rates of dry seeds, seeds as 12 h soaking with distilled water, 12 h washing by water and with ensheathe phyllary were 44%, 61%, 79.9% and 0%. Treated with 40 mg/L GA, the seed germination enhanced significantly as the maximum seed germination rate was 94% after 2 d. Treated with 40 mg/L IAA and 40 mg/L 6-BA, the seed germination delayed as the maximum seed germination rate appeared after 7 d, and the difference of seed germination index between treated and CK was significant (P<0.05). In the sand burying depth 0-6 cm, with the depth increasing, the seed germination rate gradually increased. But above 6 cm, when the depth increased, the seed germination rate gradually decreased. Moreover, as the sand burying depth increased, the root length changed in parabola-shaped and the stem length increased, but the root top radio decreased. CONCLUSIONS: The phyllary and seed of Ephedra sinica contain some seed germination inhibitors, adequate water washing, dealing with GA and so on can improve the seed germination rate and speed up the seed germination. Appropriate deep sand burying can also improve seed germination and seedling emergence of Ephedra sinica.

[First derivative spetrophotometric direct determination of 2-hydroxy-4-methoxybenzo phenone in polyester resin by computer assistant].

2-hydroxy-4-methoxybenzo phenone (UV-9) is one of general auxiliary reagents used in paint resin and plastics, which can delay the material degradation and ageing of high polymer. Direct determination of high polymer by ultraviolet spectrum has not been reported. We selected an efficient solvent that can dissolve the resin of high polymer, and got an even, transparent and steady mensuration system. The first derivative absorption data of 2-hydroxy-4-methoxybenzo phenone (UV-9) were treated many times with smooth handing by Origin 6.1, a famous data analysis software. At a certain wavelength, the results accord with Beer's law from 1.000 to 20.00 microg x mL(-1), thus UV-9 can be measured directly. Its absorptivity is 5.7 x 10(4) L x mol(-1) x cm(-1). The results of synthetic samples determined by this method showed that the relative standard deviation and the relative error of UV-9 are less than 5.25% and 4.75% respectively, and the UV-9 recovery rate is 98.88%-102.04%.