So I wrote this article on my own, and shared it between my friends via online, but I did not want anyone to use it for any monetary reasons, such as publishing it into a book and selling it. Is there a disclaimer I can use to tell people to not publish the article, and keep it private from publicity?
That's what a copyright notice is for. It informs the public that the work is copyrighted, when it was copyrighted, and who owns the copyright.
This is the standard form of a copyright notice:
© 2017 James Homicker
If your friends know the meaning of the copyright notice, that's all you need. If not, add a line at the top of your article, asking them not to copy, distribute, or publish the article for any reason.
ETA: I noticed that you said "for any monetary reasons." If you wish to allow non-commercial use of your article, consider issuing a "creative commons" license. The For Licensors section of the CreativeCommons.org FAQ offers guidance on how to choose and apply an appropriate license.
I am not a lawyer, but I do know you own the copyright on the material from the moment you finished it. Other's cannot publish it for money without your permission. Unfortunately, you need to get a lawyer to write a cease-and-desist letter for anybody that does, or perhaps you can find a model for one online, but the copyright is yours. Which means nobody else has the right to publish copies of it for any reason unless you grant them that.
IANAL but you should have a lawyer draft a Non-Disclosure Agreement (NDA) that they all must sign in order to read. This then protects you from having them leak your article. Details in the NDA can provide any retribution should they break the NDA. However they all need to sign an NDA. That legally holds them responsible to your wishes of keeping it private and holds them legally accountable for any actions that violate the agreement signed.