Dear Philanthropist,
Professional ethics are related to the moral issues that arise due to the specialized know-how which professionals attain, and how the use of this knowledge should be governed when providing a service to the public. It is more along the lines of a code of conduct. For example, lawyers are supposed or obliged to maintain confidentiality in clients' cases, even if they may be aware of other facts personally. However, their professional ethics guide them to diligently follow their code of professional ethics and seek justice.
Business ethics or Corporate Ethics is a form of applied ethics that examines ethical principles and moral or ethical problems that arise in a business environment, such as international business ethics and ethics of production.
On the other hand, General Ethics are a set of moral codes or conduct, such as righteousness, etc. The above-mentioned points of differentiation are according to my knowledge. Hope this piece of information helps you :)
Best Wishes,