I am going through the same situation as you! I adopted a new puppy about a month ago and just returned to work (I’m a teacher too) on Thursday. Before I started back to work, I started separating both of my pits, who happen to be about the same age as yours, and leaving the house for several hours. For the puppy, I put him in his crate and left the TV or radio on as well as a light and the fan. I made sure to give him a few toys to play with as well as some food and treats in his crate. He cried the first couple times I left him but after a couple days, he became used to it. I started out only leaving him for a couple hours and gradually increased the amount of time that he’s in the crate. He now stays in his crate roughly 8-9 hours and has done fine.
I would suggest getting up a little earlier with the dogs and getting them outside to play. I’ve given myself an additional hour in the morning to allow the pups to run around outside a bit. It lets them release some energy, go to the bathroom, and just be with each other. It seems to make the 8-9 hours of being crated easier for them.
It will take some getting used to but eventually both dogs will get in a routine. They’ll definitely want to run around and play once you get home, so make sure you dedicate time to play with them.