Hi – The short answer is yes you can, but how this works will depend on how the business is run. Are you running the business directly (ie as a sole trader) or have you set up a company through which the business will be run?
If you are running as a sole trader the business is not separated from your own tax affairs and you do not need to charge interest. You should still have a separate business bank account and keep records of the loan and all business transactions.
If you have set up a company then a market interest rate should be charged (there is generally less sensitivity around an interest free loan to a company you wholly own than from a company however). The interest expense should be tax deductible to the company and the interest income will be included in your personal tax return. There may also be withholding tax obligations.
Aside from potential withholding tax admin a loan is a very flexible way of providing funding to/from a business. You should think about the overall business to decide what is best (for example if the business is loss-making in the first year the interest is going to widen this tax loss while giving you a tax liability.