How to generate xml with prefix namespace? C#

Question

I want to generate the code is as follows

 

<b:library xmlns:b="http://www.library/.com/library">

<b:book>

<b:idbook>220</b:idbook>

<b:title>Name book</b:title>

<b:pages>213</b:pages>

<chapter xmls="http://www.chapters/.com/chapters">

<title>Introducción</title>

</chapter>

</b:book>

</b:library>