Yes. Zakat is an act of worship (ʿibādah), and the Prophet (ﷺ) said that deeds are only by their intentions, so the payer must intend that what he is giving is his obligatory zakat and not merely voluntary charity. The intention is a matter of the heart and need not be spoken aloud, and it is enough to intend it at the time of paying or when setting the money aside. If a person gives money away as general charity without intending zakat, it does not count toward the zakat obligation.
Evidence — the daleel
Sahih al-Bukhari 1 ṢaḥīḥSahih Muslim 1907 Ṣaḥīḥ
On deen2u
Informational, not a personal fatwa. Consult a qualified scholar for rulings on your situation.