进一步增加氟硼酸铵的量，少量的F原子成功嵌入碳材料，而N原子含量减少，

With further increase in the amount of ammonium fluoroborate, a small amount of F atoms were successfully inserted into the carbon material, while the content of N atoms decreased. This is because the doped F atoms occupy some sites where N species will be formed, resulting in a lower nitrogen content. When ammonium fluoroborate is excessive, a large number of F atoms are embedded in the carbon material, completely occupying the sites of N and B species, making it difficult for N and B atoms to be embedded in the carbon material

Further increasing the amount of ammonium fluoroborate, a small number of F-atoms were successfully embedded in the carbon material, while the N-atom content decreased, due to doped F-atoms occupying some of the spots that would form N species, resulting in lower nitrogen content. When ammonium fluoroborate is excessive, a large number of F-atoms are embedded in carbon materials, completely occupying the positions of the N and B species, resulting in N and B atoms difficult to embed carbon materials

Further increasing the amount of ammonium fluoborate, a small amount of F atoms are successfully embedded into the carbon materials, while the content of N atoms decreases. This is because the doped F atoms occupy some sites that can form n species, resulting in a lower nitrogen content. When ammonium fluoborate is excessive, a large number of F atoms are embedded in carbon materials, occupying the sites of N and B species completely, which makes it difficult for N and B atoms to be embedded in carbon materials<br>