Hi, I'm currently a 3rd year chemistry student and have spent some time recently thinking about 'what next'. Is doing a PhD worth an extra three years at uni. Is there much of a wage increase available if I was to do a PhD. Thanks.

no.
Its good for the intellect and thats it. Do something else if you want to make some money.

If you want to gain some work related expierence while still doing some research, consider applying for a Knowledge Transfer Partnership. For more information, visit http://www.ktponline.org.uk

Whilst a PhD can help you into a number of careers and is essential if you wish to continue in academia, there are easier ways to make money.

I understand it is vital for academia but what about joining industry. Surely it will be of great use there.

David, have a look at the "Value/Purpose of Phds" thread.