Piezo not loud enough
The device you pictured seems to be a switch-mode power module which will output 10V DC. Get rid of it before you do any damage.

You don't post any link to data, but I assume you mean the Transducer needs 10V peak-to-peak.

This can easily be accomplished by using 2 digital outputs, connected to the transducer, and driven in anti-phase.

The answer to Push-Pull tone code may be an answer to your problem, but may be overkill. If you just want to output a single tone it is easily done with simple code.

I don't know why you think the transducer outputs 50dB. If it really is doubling the drive voltage will only give 56dB.