Nitrogen-doped carbon materials exhibiting high oxygen reduction reaction activity were prepared via the pyrolysis of a poly-p-phenylenediamine/carbon black composite. The as-synthesized cata- lyst showed excellent ca...
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Nitrogen-doped carbon materials exhibiting high oxygen reduction reaction activity were prepared via the pyrolysis of a poly-p-phenylenediamine/carbon black composite. The as-synthesized cata- lyst showed excellent catalytic activity in alkaline solution, and outperformed commercial Pt/C in KOH solution （0.1 mol/L）, as demonstrated by the higher current density and the more positive half-wave potential. Scanning electron microscopy and N2 adsorption-desorption analyses indicated that a composite structure, in which the N-rich surface of the poly-p-phenylenediamine had an in- creased active center concentration and the high external surface area of the carbon black was conducive to the mass transport, is highly beneficial in terms of promoting the oxygen reduction reaction. However, the activity of this catalyst underwent an obvious decrease following exposure to air for 30 d. X-ray photoelectron spectroscopy showed that the oxygen content in the catalyst was increased by prolonged air exposure. O ls spectrum showed increases in the C：O and C-O compo- nents, suggesting that atmospheric oxygen reacted with the catalyst. This oxidation leaded to the deactivation of active center, thus the catalytic activity decreased. Based on these results, the stabil- ity in air of nitrogen-doped carbon materials must be taken into consideration when assessing ap- plications as alternatives to platinum-based materials.
Rechargeable Li-CO2 batteries provide a promising new approach for carbon capture and energy storage technology. However, their practical application is limited by many challenges despite much progress in this technol...
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Rechargeable Li-CO2 batteries provide a promising new approach for carbon capture and energy storage technology. However, their practical application is limited by many challenges despite much progress in this technology. Recent development in Li-CO2 batteries is presented. The reaction mechanism with an air cathode, operating temperatures used, electrochemical performance under different CO2 concentrations, stability of the battery in different electrolytes, and utilization of different cathode materials were emphasized. At last, challenges and perspectives were also present- ed. This review provides a deep understanding of Li-CO2 batteries and offers important guidelines for developing reversible and high efficiency Li-CO2 batteries.
利用一种新的原位水解沉积方法,以在高湿度空气中老化的甲醇中作为溶剂,通过乙醇钽水解而成前驱体微球颗粒沉积,制备出了高效的Ta_3N_5微球光电极,其1.6 V(vs RHE)电极电位下的光电流值达到了6.6 m A·cm^(-2)。相反地,在新鲜的甲...
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利用一种新的原位水解沉积方法,以在高湿度空气中老化的甲醇中作为溶剂,通过乙醇钽水解而成前驱体微球颗粒沉积,制备出了高效的Ta_3N_5微球光电极,其1.6 V(vs RHE)电极电位下的光电流值达到了6.6 m A·cm^(-2)。相反地,在新鲜的甲醇溶液中没有钽前驱体微球颗粒沉积。这表明甲醇中水的含量对Ta_3N_5微球光电极的形成十分重要。另外,本制备方法也能方便地在其他透明导电衬底上制备出Ta_3N_5。
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