To achieve that you will have to set which partition gets mounted as /home. That involves editing your /etc/fstab.
First make sure your present home folder is empty. Then find out what is the partition name of your home drive, use sudo fdisk -l for that. I am going to assume its /dev/sdaX for this post, replace it with yours.
Then find out its uuid
sudo blkid | grep /dev/sdaX
Take note of UUID and TYPE. Now open your fstab file for editing
gksudo gedit /etc/fstab
Fill in a new entry like this,
UUID=xxxxx /home ext4 rw,relatime,data=ordered 0 2
Replace xxxxx with your uuid and ext4 with your TYPE. You could change spaces between columns as you see fit. Reboot your linux and you're done!!
IMPORTANT NOTE!
If you have a separate partition for /home already , you will have to remove its entry from /etc/fstab as you can't mount two drives to same folder.