Li Liang, Wang Xinran, Guo Ying, Li Jinxin
Laboratory for Low Dimensions Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
Langmuir. 2020 Mar 3;36(8):1916-1922. doi: 10.1021/acs.langmuir.9b03810. Epub 2020 Feb 19.
A CoP/graphene composite was synthesized through a coprecipitation and in situ phosphorization protocol using α-Co(OH) and graphene oxide as precursors. The similar two-dimensional layered structures ensured evenly attached α-Co(OH) nanosheets on the graphene oxide support and the formation of a sandwich-like structure. The sequential in situ phosphorization strategy not only generated a high density of ultrafine CoP nanocrystals but also simultaneously reduced the graphene oxide support. The enough exposed active sites combined with a highly conductive matrix resulted in an excellent electrochemical catalyst for overall water splitting. The overpotential is only 125 mV at 10 mA·cm in 0.5 M HSO. Good electrocatalytic performance was also exhibited in alkaline conditions for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The overpotential is 119 mV for HER and 374 mV for OER at 10 mA·cm in 1 M KOH. More importantly, the composite exhibited much higher exchange current densities during HER processes (1.64 × 10 A·cm in 0.5 M HSO and 2.93 × 10 A·cm in 1 M KOH) when compared with similar materials reported before. This low-cost, simple, and efficient approach is suitable for mass production and practical applications.
通过共沉淀和原位磷化方法，以α-Co(OH)和氧化石墨烯为前驱体合成了一种CoP/石墨烯复合材料。相似的二维层状结构确保了α-Co(OH)纳米片均匀附着在氧化石墨烯载体上，并形成了类似三明治的结构。连续的原位磷化策略不仅产生了高密度的超细CoP纳米晶体，还同时还原了氧化石墨烯载体。足够暴露的活性位点与高导电基质相结合，产生了一种用于全水分解的优异电化学催化剂。在0.5 M HSO中，10 mA·cm时的过电位仅为125 mV。在碱性条件下，该复合材料在析氢反应（HER）和析氧反应（OER）中也表现出良好的电催化性能。在1 M KOH中，10 mA·cm时HER的过电位为119 mV，OER的过电位为374 mV。更重要的是，与之前报道的类似材料相比，该复合材料在HER过程中表现出更高的交换电流密度（在0.5 M HSO中为1.64×10 A·cm，在1 M KOH中为2.93×10 A·cm）。这种低成本、简单且高效的方法适用于大规模生产和实际应用。
