Afro-American vs African-American

Afro-American and African-American both are nouns.

Word	Noun	Adjective	Verb	Adverb
Afro-American	Yes	Yes	No	No
African-American	Yes	Yes	No	No

As adjectives, Afro-American and African-American are synonyms defined as:

Afro-American and African-American: pertaining to or characteristic of Americans of African ancestry

Afro-American (noun)	African-American (noun)
an American whose ancestors were born in Africa	a person with African ancestry, "Negro" and "Negroid" are archaic and pejorative today

Afro-American (adjective)	African-American (adjective)
pertaining to or characteristic of Americans of African ancestry	pertaining to or characteristic of Americans of African ancestry