You always have to protect your material against air, which will burn it otherwise. You can dope it with N by mixing with a nitrogen-rich precursor, or by passing gaseous ammonia on it as Nady wrote, but never in air as soon as the temperature is higher than 200 - 300°C for most carbon materials. N2 never reacts with carbon below 1000°C, and above this temperature, it forms volatile cyanide-like species, so there is no chance to dope your cabon in a flow of N2.

Alain

I suggest you can insert ammonia during pyrolysis of carbon precursor, this gives you high content of N-carbon.

You always have to protect your material against air, which will burn it otherwise. You can dope it with N by mixing with a nitrogen-rich precursor, or by passing gaseous ammonia on it as Nady wrote, but never in air as soon as the temperature is higher than 200 - 300°C for most carbon materials. N2 never reacts with carbon below 1000°C, and above this temperature, it forms volatile cyanide-like species, so there is no chance to dope your cabon in a flow of N2.

Alain

It is impossible task. You need to use some precursors in which the binding energy of nitrogen molecules is less then in pure gaseous N2 (or air). Solid precursors such as melamine (C3H6N6) and Sodium azide (NaN3) are widely used. Also ammonia as gaseous precursor is used due to higher chemical activity. In article "State of art and recent trends in carbon nitrides synthesis you can find a lot of information which will be interesting for you. The link: http://www.sciencedirect.com/science/article/pii/S0927796X07000988

best regards

you can't as you decompose any nitrogen sources in presence of  air it converted in nitrogen oxide

N-doped carbon materials cannot be prepared under atmosphere because N-containing groups can easily be oxidized at high temperature.

Best!

Hongjie