On this occasion, I strongly disagree with RP. It's entirely usual to use the body diodes of power mosfets as the flyback diodes in a mosfet H-bridge. 1N4001 and similar diodes are much less suitable because they don't switch off as fast. The only reason not to rely on the mosfet body diodes is if there is so much energy flowing through them from the motor that the mosfets get hot. In this case, using Schottky flyback diodes would be an advantage. You would need to be using a very large motor for this to be a consideration.
What you DO need is a large capacitor between the motor supply +ve and motor supply ground terminals of the H-bridge, to absorb the power flowing through the flyback diodes (whether you are using external flyback diodes or not). Something like 1000uF electrolytic in parallel with 1uF or greater ceramic.
Single mosfets driving motors are a different matter entirely. In that configuration, the body diode is in the wrong place in the circuit to act as a flyback diode. With an H-bridge, the body diode of the upper mosfet acts as the flyback diode when the lower mosfet turns off, and vice versa.