For the List of PhD. topics you can consult 'University News' a weekly news journal. It is publishing the awarded PhD. in different universities in same time.
Rather than giving suggestions on topics for Ph.D, I would like to give you some tips on searching a topic for Ph.D.
First of all think of some broad areas of your interest in the field of LIS.
Go through some abstracting databases such as PoQuest (Thesis database), EBESCO, LISA etc. for the latest research trends on these topics.
Then try to zero down and limit your research problem on a specific topic.