FeCo-N encapsuled in nitrogen-doped carbon nanotubes as bifunctional electrocatalysts with a high stability for zinc air batteries

For zinc air batteries,a non-noble metal-based electrocatalyst with a high performance and stability in oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)is imperative in application.Herein,a catalyst based on FeCo-N encapsuled in nitrogen-doped carbon nanotubes has been prepared,which provides an implementable method to design controlled structures with excellent bifunction al electrocatalytic activities.By adjusting the molar ratio of two metals,the synthesized FeCo-N-C catalyst delivers a competitive ORR and OER performance compared with commercial Pt/C and IrO_(2),performing a low overvoltage gap between ORR(E_(1/2))and OER(E_(j=10))of 0.8 V.Moreover,as a promising cathode in zinc air battery,the FeCo-N-C catalyst possesses an affirmative stability of over 100 h and large power density(129 mW·cm^(-2)).This work demonstrates that FeCo-N-C is one of the most promising catalysts for zinc air batteries and provides a possibility for exploration of batteries with high stability by adjusting the molar ratio of metals in the catalysts.

TiO_2钝化ZnO阵列增强量子点敏化太阳电池的光俘获和电子收集（英文）

光捕获和电子复合决定着量子点敏化太阳电池的光电效率(PCE).众所周知,在纳米棒阵列的量子点敏化太阳电池中电荷更容易传输.然而,氧化锌(ZnO)阵列表面的缺陷会引起电荷快速复合.因此,我们利用H_3BO_3和(NH_4)_2TiF_6溶液合成了正交结构的二氧化钛(TiO2)纳米粒子并用其对ZnO纳米棒包覆,形成了复合纳米结构.该结构利用了纳米颗粒提供的大比表面积以及纳米棒优良的电子传输特性,以期获得良好的电荷传输和光捕获能力.同时,由于TiO_2修饰后的ZnO纳米棒阵列的表面复合中心(羟基)较少,ZnO纳米棒表面上发生的电荷俘获减少,从而降低了电荷复合,延长了电子寿命.TiO_2修饰后太阳电池的PCE达到4.80%,比未修饰电池的PCE(2.7%)提高了约78%.