Hourly room to rest at arrival hall of Beijing airport terminal 3

We are arriving at Terminal 3 at midnight of 21Dec 2017. We will go through the immigration and custom and will be outside the arrival gate. Our friends will pick us up at 9 am on 22 Dec 2017. We need to find a room to rest while waiting for our friends to pick us up at 9 am. Where can we find a room within the Terminal 3 without leaving the airport?