301 redirect to web2.0

I have a domain with some backlinks, can I 301 redirect it to my web2.0 buffer site? Will this help for ranking?

Instead of just removing the redirect, you should check the reason why your SEO was affected.

1. Is the domain spammy? If this is the case, you should remove the redirect. Submitting a disavow file may help.
2. Have you done the redirect correctly? When the reader clicks on a link from another website, do they get what they expect? If not, then you did the redirect incorrectly and you will get a “soft 404″ error. User experience is very much part of SEO.

A correct redirect would include recreating the pages that the links point to with quality content and individually redirecting each URL, making sure relevancy is maintained. Otherwise people will click on your links, then bounce immediately and that will kill your SEO.

Why redirect to a web2.0? you should build a website and link from it, rather than redirect it.. remember that the web2.0 isn't something you own and could be deleted at any given point

Why not. However, if the expired domain is good it's better to build a pbn. However, if it still has good links, but it has been spammed in the past redirecting it to a web 2.0 could work.