Microwave plasma device with increased selectivity of nitrogen oxide and method of producing nitrogen oxide-containing water using same

A method of producing nitrogen oxide, comprising:

• injecting a swirl gas into a hollow tube;
• passing the injected swirl gas through a gap formed between a swirl gas barrier and the hollow tube;
• injecting an axial gas into the hollow tube;
• irradiating a microwave to the hollow tube;
• and
• generating plasma inside the hollow tube and generating nitrogen oxide gas.

A method of producing nitrogen oxide-containing water, comprising:

• injecting a swirl gas into a hollow tube;
• passing the injected swirl gas through a gap formed between a swirl gas barrier and the hollow tube;
• injecting an axial gas into the hollow tube;
• irradiating a microwave to the hollow tube;
• generating plasma inside the hollow tube and generating nitrogen oxide gas;
• and
• plasma-treating the generated nitrogen oxide gas into distilled water to produce nitrogen oxide-containing water.