Charging voltage

You can charge an iPhone, iPad or iPod Touch with any quality USB-A or USB-C power source and matching cable. Essentially any Apple power source and cable that fit into the connectors at either end are compatible and safe to use.

For more info, see:

When to charge your iPhone or iPad - Apple Community

Nope, all universal, it will be fine.

The charging voltage is always USB standard 5v. All USB power supplies will output 5v but the current may vary depending in the wattage capacity of the power supply.

What if we use Adopter of android & data cable of an iPhone? Is it harmful for IOS devices? Thanks in advance.

You mean that the batter performance will remain same? Thanks in advance.