Yes light cannot escape them, which is because of the incredibly strong gravity well of a black hole.

The very recent articles on black holes and dark energy are very speculative.

Dark energy and black holes are separate. Black holes are objects that are black because their gravity well is so strong that light cannot escape them. Dark energy is a force that pervades all of spacetime. We measure how much dark energy there is by the red shift of galaxies outside of our local group, and other standard candles like class 1a supernova and Cepheid variable stars. Is there a dark energy particle? Is it a fundamental force like the strong force in an atom? We don't know. So far we can just measure its impact on the expansion of the universe.