we will have a 16 hour lay over in shanghai. is there a hotel where we can spend some time to sleep?

Yes, definitely, you can find a hotel for you near the airport.
As for the visa, you do not need a visa, since you stay there for no more than 48 hours. You show your valid passport, visa of your destination country and connecting flight ticket to the staff, and then you are allowed to go out of the airport.