PhD topic selection is an important process and the one in which scholars get confused
Select a topic in the area which you are interested in, and have more knowledge about.
Be confident with what you choose.
Choose topics which creates impact or changes by the research.
Be specific on what you are going to do.
Chapter 1 - Introduction
Chapter 2 - Model and Implementation
Chapter 3 - Methodology
Chapter 4 - Analysis of data obtained
Chapter 5 - Body of the research