To uncover the distinction in the electronic density of states (DOS) near Fermi level at the graphene and metal, we compare the standard rate constant k⁰ values for quinone species at graphene and gold nanoelectrodes, which might be affected by the electronic DOS near Fermi level. The experimental result indicates that the k⁰ value obtained at the individual graphene flake of nanometer size is very close to that obtained on gold nanoelectrode, and higher than that at large graphene flake. Unlike the high electronic DOS in gold nanoelectrodes, the difference of k⁰ values at graphene nanoelectrodes of different sizes will reveal the size-dependent DOS at single graphene flake.

为了揭示石墨烯和金属在费米能级附近的电子态密度（DOS）的区别，我们比较了石墨烯和金纳米电极上醌类的标准速率常数k ⁰值，这可能受费米附近的电子DOS影响等级。实验结果表明，在单个纳米尺寸的石墨烯薄片上获得的k ⁰值非常接近在金纳米电极上获得的k ⁰值，并且比在大石墨烯薄片上获得的k ⁰值更高。与金纳米电极中的高电子DOS不同，在不同尺寸的石墨烯纳米电极上k ⁰值的差异将揭示单个石墨烯薄片上与尺寸有关的DOS。