The lower or base Nafs is mentioned in the Quran. Here are some contexually separate ayahs as references, the first refers to the Naf’s Ammara and the second and third to the lower (base) Nafs which is also termed “soul” or “self” in this translation:
REGARDING THE INCIDENT OF SAYYIDNA YUSUF WITH THE WIFE OF THE MINISTER
012.053 YUSUFALI: “Nor do I absolve my own self (of blame): the (human) soul is certainly prone to evil, unless my Lord do bestow His Mercy: but surely my Lord is Oft-forgiving, Most Merciful.”
PICKTHAL: I do not exculpate myself. Lo! the (human) soul enjoineth unto evil, save that whereon my Lord hath mercy. Lo! my Lord is Forgiving, Merciful.
SHAKIR: And I do not declare myself free, most surely (man’s) self is wont to command (him to do) evil, except such as my Lord has had mercy on, surely my Lord is Forgiving, Merciful.
REFERENCE TO THE LOWER SELF REGARDING THE INCIDENT OF THE SONS OF ADAM (AS)
005.030 YUSUFALI: The (selfish) soul of the other led him to the murder of his brother: he murdered him, and became (himself) one of the lost ones.
004.079 YUSUFALI: Whatever good, (O man!) happens to thee, is from Allah; but whatever evil happens to thee, is from thy (own) soul. and We have sent thee as a messenger to (instruct) mankind. And enough is Allah for a witness.
PLEASE ADD OTHER REFERENCES FROM THE QURAN ON THE LOWER NAFS,
JAZAAIK ALLAH HU KHAIRAN.