When you mention a professor in your thesis, it is important to show why you are including them. For example, you might say "Professor Smith has done groundbreaking research in the field of XYZ, and I have used their work extensively in my own research." By acknowledging the professor, you are showing that you are aware of their work and that it has informed your own thinking.
It is also important to be specific about what you are acknowledging. For example, if you have used a professor's data in your research, you would want to say so. If you have built on their theoretical framework, you would want to say so. This shows that you have read and understood their work, and that you are not simply including them for the sake of it.
Finally, it is also polite to thank the professor for their work. This can be done in a sentence or two at the end of your acknowledgement.