What not to do! Do not spray any coating to the area. Do not wrap the area. Trees heal by  setting set up a healing "scab" around the area. To help with the process you can take a razor knife to clear ragged areas back to firm healthy areas. Through this process, trees can close off injured portions of wood and seal them from the rest of the plant. They can also prevent nutrient decay before it becomes a problem for the tree’s root system. This prevents the spread of infection and is one of the most common wound reactions for trees
The extent of this damage is life-threatening for the tree. You might want to consult a certified arborist.