Here are some ideas for a persuasive/informative essay:
Water pollution
Animal rescue (A lot of animals need help and you could tell people about the environment in which animals are in and how to fix it (adopt))
Why sports is dangerous
Why a specific sport should be banned (like football because it is a sport that is super dangerous and causes damages to the brain, leading to medical problems)
(I always used these topics and got A's, but it all depends on what point you are trying to come across). I can comment more based on what you are trying to do (persuade someone or inform them, ext.)