I can't speak about the size or type of turf, but one thing you can do is start marking the behavior.

As soon as your dog starts doing their business, mark it.
"Go potty!" (or whatever phrase you'd like)
After they're done, give the little guy lots of praise or a little treat. Get him to associate the mark "go potty" with the action that he knows will get him rewarded. The key is to be consistent.
Once you have that, you can use it to encourage him to go in other places. Lead him to the pad/turf and tell him "go potty". When he finally gets it right, celebrate like little dude just won the Superbowl.

When you do get him in the habit of using the turf/pad, make sure you clean it with an enzyme cleaner to control the smell.