In this work, graphitic carbon nitride (g-C3N4) was modified by Pd nanoparticles (Pd-CN) to prepare an efficient cathode catalyst for Li-O2 batteries. The specific surface area of g-C3N4 was improved to 239.56[Formula: see text]m2/g by two-steps thermal polymerization. Pd nanoparticles were loaded onto the g-C3N4 by K2PdCl4 reduction with NaBH4. The resulted Pd-CN composites were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscope, and transmission electron microscope. The results proved that g-C3N4 showed three-dimensional layered and porous structure, and Pd nanoparticles were successfully supported on it. The Li-O2 batteries using Pd-CN composites as cathode catalysts were assembled and tested. The maximum initial discharge specific capacity reached 26,614[Formula: see text]mAh[Formula: see text]g[Formula: see text] at current density of 100[Formula: see text]mA[Formula: see text]g[Formula: see text]. The electrodes remained large capacity under high current density, meaning excellent rate capability. Li-O2 batteries containing Pd-CN cathode were continuously cycled for 70 cycles with no loss of capacity and obvious change in the terminal voltage. These electrochemical results indicated that the loading Pd nanoparticles effectively increased specific capacity, reduced overpotential and improved the cyclic stability. The Pd-CN composites are proved to be the promising cathode catalysts for Li-O2 batteries.

中文翻译：

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用 Pd 纳米粒子改性的石墨氮化碳用于 Li-O2 电池的高效阴极催化剂

在这项工作中，石墨氮化碳 (gC3ñ4) 被 Pd 纳米粒子 (Pd-CN) 改性以制备高效的 Li-O 阴极催化剂2电池。gC的比表面积3ñ4提高到 239.56[公式：见正文]m2/g 通过两步热聚合。将 Pd 纳米颗粒加载到 gC 上3ñ4由 K2氯化钯4用 NaBH 还原4. 采用 X 射线衍射、X 射线光电子能谱、场发射扫描电子显微镜和透射电子显微镜对所得 Pd-CN 复合材料进行了表征。结果证明，gC3ñ4显示出三维层状和多孔结构，并且成功地负载了Pd纳米颗粒。锂氧2组装和测试了使用 Pd-CN 复合材料作为阴极催化剂的电池。最大初始放电比容量达到26614[公式：见文]mAh[公式：见文]g[公式：见文]电流密度为100[公式：见文]mA[公式：见文]g[公式：见正文]。电极在高电流密度下仍保持大容量，这意味着优异的倍率性能。锂氧2含 Pd-CN 正极的电池连续循环 70 次，容量无损失，端电压变化明显。这些电化学结果表明负载钯纳米粒子有效地增加了比容量，降低了过电位，提高了循环稳定性。Pd-CN复合材料被证明是有前途的Li-O正极催化剂2电池。