Hand in notice without another job

After graduating from uni last year I took a job as a science technician. For a variety of reasons including a commute of 3 hours combined, a lack of potential progression within the company and working in an environment with potentially hazardous fumes I have decided want to find a new job.

I have applied for a number of jobs, three of which I was given a phone interview and asked to go in for a face-to-face interview. However, whenever I mention my notice period is three months the recruiter immediately seems to get cold feet about my application. I was going smoothly through the recruitment process with one company, I then said notice period is 3 months and they said they'll try and arrange an interview for me, 3 weeks later I'm still waiting for an interview date after positive feedback about my CV, application and phone interview.

I've decided that I need to hand in my notice period now, and then look for a new job. Then I can give potential recruiters an exact date to expect me to finish (it may be sooner then 3 months as it has happened with a few employees already).

Is this a wise idea? My fear is I could end up finishing my job 2-3 months later with nothing lined up, then desperately looking for a new job afterwards. But at the moment, working full time and travelling 3 hours a day I have very little time or energy to look for a new job.

Going a month without getting paid will affect me but it won't be critical as I have saved up from my current employment to cover me, I'm more worried about having a gap in my CV of a couple of months out of employment and the affect it would have on morale. Also getting a 2.2 in physics I'm not sure how employable that would make me, although my GCSE grades were exceptional and my A levels were relatively good, I now I would get a very good reference from my current employer- which I wouldnt' be able to use if I did look for a job without handing in my notice.