Yes, you can use MacBook Pro chargers for iPhone and iPad fast charging

Recommendations for fast-charging iPhone or iPad often include picking up the $20 18W power adapter from Apple or similar from a third party, but if you already have a higher-powered USB-C charger for your MacBook Pro or MacBook Air, you’re all set.
Apple’s flagship iPhone 11 Pro Max in Midnight Green
Michael Potuck for 9to5Mac:Most recent iPhones and iPads work with all of the Mac notebook USB-C chargers, even the 96W model that comes with the 16-inch MacBook Pro. While it may sound