What are some good research topics for a high school student?
Green chemistry is a highly advanced topic. It ain't for the weak of heart, so it is probably not for below university level.

I personally favor pyrotechnics as relatively safe iff every bit of safety rules is strictly followed and stunningly spectacular topic that is pretty easy and cheap to do by own hands (most materials are inexpensive as well as most tools). However, it is extremely time-consuming and has questionable legal status in some countries (and for a good reason: safety may be easily compromised and potential for disaster is high). 

Another interesting topic is fluorescence. Many compounds shine under UV light, and there are families of such compounds that are not exhaustively studied and yet are relatively easy to make. However, a deep study is required, but it is probably advanced school level.

With access to advanced materials/tools/labs more topics become available, but a full list of such tools is required to recommend anything.