No he didn’t. Go look. He imposed sanctions to individuals and companies. Nothing that would ever effect Putin or the economy.

And yes he did remove sanctions .

After putin seized Crimea, Obama put sanctions on Russia. Trump promptly got rid of those sanctions for his buddy, then declared that Crimea belonged to Russia, recognizing the legitimacy of their invasion.

“The Trump administration has lifted sanctions on three firms linked to Russian oligarch Oleg Deripaska, an ally of President Vladimir Putin.”

https://www.bbc.com/news/business-47023004

Putin keeps his money with the oligarchs. Follow the money. That’s usually how you can keep track of corruption .