Hi. Unfortunately it is well known that sometimes 3rd party chargers may damage your device(http://www.macrumors.com/2014/06/19/iphone-5-faulty-chips/)
You may try to do the following: Force your device to start. To do this, press Sleep/Wake and Home buttons and hold them for at least 10 seconds.
Try to reset your device. This won't delete your data stored on the phone.
- Press and hold the Sleep/Wake button
- Press and hold on the Home button
- Keep holding both buttons until the display turns off and back on with Apple logo on it.
If this does not help, take a look these Apple Support articles:
If your iPhone, iPad, or iPod touch doesn't respond or doesn't turn on - Apple Support
Use iTunes to restore your iPhone, iPad, or iPod to factory settings - Apple Support.
If nothing above works, it is high time to take your phone too the Apple Store. Good luck.