No, corys don’t eat algae. Even though cory catfish are bottom feeders, they won’t eat algae that grow on the tank walls or substrate. They might eat sinking algae wafers occasionally, but in general, corys refuse to eat algae. For that reason, you can’t rely on your corys to clean up the tank if algae bloom occurs.
However, having corys can help prevent algae blooms from happening in the first place. Corys scavenge on scraps and leftover foods in the tank. Thus, they can help reduce the overall growth of algae in your tank.