Endowing the Operability of Supercapacitors at High Temperatures by Regulating the Solvation Structure in Dilute Hybrid Electrolyte with Trimethyl Phosphate Cosolvent.

The redox stabilities of different oxygen donor solvents (C═O, P═O and S═O) and lithium salt anions for supercapacitors (SCs) electrolytes have been compared by calculating the frontier molecular orbital energy. Among six lithium difluoro(oxalate)borate (LiDFOB)-based mono-solvent electrolytes, the dilute LiDFOB-1,4-butyrolactone (GBL) electrolyte exhibits the highest operating voltage but suffers from electrolyte breakdown at elevated temperatures. Trimethyl phosphate (TMP) exhibits the highest redox stability and a strongly negative electrostatic potential (ESP), making it suitable for promoting the dissolution of LiDFOB as expected. Therefore, TMP is selected as a co-solvent into LiDFOB-GBL electrolyte to regulate Li+ solvation structure and improve the operability of electrolytes at high temperatures. The electrochemical stable potential window (ESPW) of 0.5 m LiDFOB-G/T(5/5) hybrid electrolyte can reach 5.230 V. The activated carbon (AC)-based symmetric SC using 0.5 m LiDFOB-G/T(5/5) hybrid electrolyte achieves a high energy density of 54.2 Wh kg-1 at 1.35 kW kg-1 and the capacitance retention reaches 89.2% after 10 000 cycles. The operating voltage of SC can be maintained above 2 V when the temperature rises to 60 °C.

[Progress on sORF-encoded micropeptides].

Existing research has shown that there are a large amount of non-coding RNAs (ncRNAs) in organisms. Short open reading frames (sORFs) abundantly exist in molecular sequences inaccurately annotated as ncRNAs. Several sORFs can be transcribed and translated into evolutionarily conserved micropeptides, which were ignored in previous studies due to short sequence lengths and the limitations of research techniques. To date, sORF-encoded micropeptides with various functions have been found to play important roles in regulating vital biological activities. This article reviews the functional micropeptides which have been found in recent years, introduces the new micropeptide designated as MIAC that we have discovered and describes the related technologies for mining potential micropeptides, thereby providing insights and references for new micropeptide discovery for researchers.

Dual surface modification of carbon materials by polydopamine and phosphomolybdic acid for supercapacitor application.

Surface modification of carbon materials is an important issue for its potential application. In this work, this purpose has been successfully achieved by the incorporation of polydopamine (PDA) and phosphomolybdic acid (PMA), forming carbon/PDA/PMA hybrid electrode materials, in which PDA acts both as a linker molecule and as a pseudo-capacitance provider, and PMA contributes to pseudo-capacitive performance. It is revealed that adding PDA and/or PMA results in a decrease of porosity but in an increase of electrical conductivity and thus a suitable combination of porosity, conductivity, and pseudo-capacitance is vital for achieving the optimization of capacitive performance. By using the Trasatti method, we found out that increasing PDA or PMA results in the improvement of pseudo-capacitance proportion and the C-PDA/PMA-1 : 1 sample exhibits a pseudo-capacitance proportion of 32%. In a two-electrode configuration, the C-PDA/PMA-1 : 1 sample delivers a specific capacitance of 101 F g-1 at 1 A g-1, a cycling performance of 108% within 10 000 cycles, and an energy density of 3.5 W h kg-1 (nearly 3.2 times that of the C-blank sample) at 500 W kg-1. Moreover, the dual surface modification of PDA and PMA could be extended to other energy storage systems, highly improving capacitive performance by the synergic effect.

Fabrication of magnetic carboxyl-functionalized attapulgite/calcium alginate beads for lead ion removal from aqueous solutions.

In the present study, we synthesized an effective Pb(II) adsorbent from magnetic carboxyl-functionalized attapulgite (McAPT) and sodium alginate (Alg) by simple mechanical agitation at room temperature. The novel McAPT@Alg composite was systematically characterized using a number of instrumental techniques, and the effects of adsorbent dosage, initial concentration of Pb(II), adsorption time, pH, and temperature on the adsorption capacity were investigated by performing batch experiments. The obtained results demonstrated that adsorption equilibrium could be reached within 1.5 h, with the maximum adsorption capacity being 471.20 mg g-1 while the temperature was 297.2 K. The experimental data were suitable for application to the Langmuir isotherm model, and the adsorption kinetics agreed with the pseudo-second-order model. More importantly, a Pb(II) removal efficiency of >70% could be achieved after 6× adsorbent recycling, which demonstrated the excellent potential of McAPT@Alg for removing Pb(II) from contaminated water.

The effects of amine/nitro/hydroxyl groups on the benzene rings of redox additives on the electrochemical performance of carbon-based supercapacitors.

In this work, a series of porous carbon materials with hierarchical porosities have been synthesized via a template carbonization method, in which cheap CaCO3 serves as a template and glucose as a carbon precursor. During the carbonization process, CO2 produced by the decomposition of the CaCO3 template can act as an internal activating agent, significantly improving microporosity and mesoporosity. All the carbon materials obtained by regulating the ratio of glucose to CaCO3 exhibit the amorphous features with a low graphitization degree. Among them, the carbon-1 : 2 sample shows a high BET surface area of up to 818.5 m(2) g(-1) and a large total pore volume of 1.78 cm(3) g(-1) as well as a specific capacitance of 107.0 F g(-1) at 1 A g(-1). In addition, a series of hydroquinone (HQ), p-aminophenol (PAP) and p-nitrophenol (PNP) as novel redox additives that can produce pseudo-capacitances have been added into the KOH electrolyte for promoting the total capacitive performances via redox reactions at the electrode-electrolyte interface. As expected, a 2.5-fold increase in the galvanostatic capacitance of 240.0 F g(-1) in the HQ-0.5 electrolyte occurs, compared with the conventional KOH electrolyte. Similarly, the PAP-0.5 electrolyte and the PNP-0.5 electrolyte also show a high specific capacitance of 184.0 F g(-1) at 2 A g(-1) (156.6 F g(-1) at 3 A g(-1)) and 153.0 F g(-1) at 3 A g(-1), respectively. Additionally, the three kinds of electrolytes exhibit excellent cyclic stability. The remarkable improvement of supercapacitors is attributed to the quick reversible Faradaic reactions of amine and hydroxyl groups adhering to the phenyl rings, which largely accelerates electron migration and brings additional pseudocapacitive contribution for carbon-based supercapacitors.

Synergistic effect of novel redox additives of p-nitroaniline and dimethylglyoxime for highly improving the supercapacitor performances.

In present work, we demonstrate a simple but effective strategy for high-performance supercapacitors by adding the p-nitroaniline (PNA) into an alkaline electrolyte of KOH. PNA possesses a unique molecular structure with the functional groups of -NH2 and -NO2. Besides, both the product of nitro-reduction (-NH2) and intrinsic -NH2 on the benzene ring can lead to the occurrence of Faradaic redox reactions accompanied by the electron/proton transfer in the mixed electrolytes, whose pseudocapacitance can greatly enhance the total capacitance. Furthermore, another effective additive of the dimethylglyoxime (DMG) has been incorporated into carbon materials for further improving the performances of supercapacitors with a PNA + KOH electrolyte. As for the DMG + PNA + KOH system, a galvanostatic capacitance up to 386.1 F g(-1) of the DMG-0.15-PNA-0.15 sample at 3 A g(-1), which is nearly two times higher than that of the PNA-0.15 sample (183.6 F g(-1)) in the PNA + KOH system and nearly three-fold capacitance of the carbon-blank (132.3 F g(-1)) in the KOH system at the same current density. Furthermore, the specific capacitance still can reach up to 260.0 F g(-1) even at 40 A g(-1) with a 67.4% capacitance retention ratio. Besides, the DMG-0.15-PNA-0.15 sample exhibits an exceptional capacitance retention of 113% after 5000 charge/discharge cycles by virtue of the potential activated process, which clearly reveals the excellent cycling stability. These remarkable enhancements are ascribed to the synergistic effects of novel additives of PNA and DMG.

Nitrogen/manganese oxides doped porous carbons derived from sodium butyl naphthalene sulfonate.

High-performance porous carbons have been prepared as supercapacitor electrode materials by co-doped with nitrogen and MnOx via a direct carbonization method, using sodium butyl naphthalene sulfonate (abbr. BNS-Na) as carbon source. It is believed that the in situ formed Na6(SO4)2(CO3) in the product would probably serve as temporary template for producing porous structures. The impacts of nitrogen/MnOx contents as well as the structures upon the capacitive performances were emphatically discussed. It indicates that introducing nitrogen and/or MnOx into the carbon matrix can remarkably improve their capacitive performances based on the cyclic voltammetry and galvanostatic charge-discharge measurements in 6 mol L(-1) KOH aqueous solution. The specific capacitances of doped carbons can reach up to ca. 167.0-241.8 F g(-1) compared with that of the undoped carbon of ca. 105.6 F g(-1). Of these samples, the carbon-Mn-1:30-N-1:15 sample co-doped with nitrogen and MnOx exhibits the highest specific capacitance and energy density up to 241.8 F g(-1) and 33.6 Wh kg(-1), respectively. In particular, these carbons also exhibit high intrinsic capacitances (i.e., capacitance per surface area) up to ca. 0.66-1.92 F m(-2).

High-performance supercapacitor based on nitrogen-doped porous carbon derived from zinc(II)-bis(8-hydroxyquinoline) coordination polymer.

Nitrogen-doped porous carbon electrodes with remarkable specific capacitance have been fabricated by the rational carbonization of zinc(II)-bis(8-hydroxyquinoline) (abbr. Znq(2)) coordination polymer, and heating treatment with CO(NH(2))(2). The experimental results demonstrate that the mass ratio of carbon precursor and CO(NH(2))(2) plays a key role in the formation of porous carbon with various nitrogen content as well as specific surface areas and pore structures. The cyclic voltammetry and galvanostatic charge-discharge measurements show that the capacitive performance has been remarkably improved by doping with nitrogen. The specific capacitance of 219.2 F g(-1) is achieved at the current density of 1 A g(-1) with nitrogen-doped porous carbon, increasing up to ca. 56.8% compared to that with pristine porous carbon. The nitrogen-doped porous carbon electrode exhibits enhance capacitance retention as ca. 45.2% at 20 A g(-1) as well as cycling stability (ca. 7.6% loss after 3000 cycles). The present carbonization method as well as the nitrogen-doping method for porous carbon from coordination polymer can enrich the strategies for the production of carbon-based electrodes materials in the application of electrochemical capacitors.

Synthesis and photoluminescence of ZnAl2O4:Eu3+ hollow nanophosphors using carbon nanospheres as hard templates.

ZnAl(2)O(4):Eu(3+) hollow nanophosphors have been for the first time prepared by using carbon nanospheres as hard templates. The ZnAl(2)O(4):Eu(3+) hollow nanophosphors were well characterized by means of XRPD, FESEM, TEM, HRTEM, N(2) adsorption and desorption and PL techniques. The N(2) adsorption and desorption data reveal the porous nature of ZnAl(2)O(4):Eu(3+) hollow nanophosphors and high surface area of 195.3 m(2) g(-1). The PL measurement illustrates red-emitting feature of ZnAl(2)O(4):Eu(3+) hollow nanophosphors arising from the characteristic transitions of Eu(3+) from (5)D(0)→(7)F(j) (j=0, 1, 2, 3, and 4). This simple and efficient synthetic strategy could be extended to prepare other series of aluminates nanophosphors with novel hollow structures.