Reference: Fataawa Noor ‘alad-Darb – Question No.6344, Pages 179-180, Volume 12
Question: Is it permissible to recite soorah al-Faatihah whilst supplicating, or at the end of the supplication? And is that [considered to be] an innovation?
Response: Certainly the recitation of [soorah] al-Faatihah during the supplication or at the end of the supplication is an innovation, because there is nothing reported from the Prophet ﷺ that he would begin his supplication with [soorah] al-Faatihah, or [even] finish his supplication with [soorah] al-Faatihah.
[As a rule, we must be aware that] introducing any act of worship which the Prophet ﷺ did not do is an innovation.
Yes, it has been [authentically] reported from the Prophet ﷺ that [soorah] al-Faatihah is to be recited over the sick person, as a means of seeking a cure; this is something which is a reality and practiced [by many]. Certainly, [there is no doubt] the recitation of [soorah] al-Faatihah upon the sick person is from the most beneficial treatments aiding healing.