郑Zhèng
The zh sound and falling tone merit practice as part of the complete name.
A historical connection
Zheng He, the Ming voyager, is a historical bearer. His story is not a surname origin for present users.
The named reference here is Zheng He. It gives a point of entry into history; it cannot establish the origin or genealogy of everyone who writes this surname.
What to check in your own name
Say the whole name aloud, including its surname/given-name boundary. Check the surname’s tone and whether the next syllable begins comfortably. If your family already uses a Chinese surname, use its own documented written form and reading instead of replacing it with an attractive historical story.
These combinations are exploration examples. Only the linked dossier’s original surname pairing has its specific editorial note; a changed surname needs fluent-speaker review.
Sources & limits
Sources support the specific facts cited above. An editorial name interpretation is not an ancient quotation or proof of family ancestry.