Apple's OEM iPhone & iPad charger are dual voltage, auto-sensing (110-220/240 volt) but come with No.America style plug. If you travel frequently, invest in a set of plug adapters - sold @Amazon (similar ones at Walmart & Target - usually in the luggage/accessory sections) - http://www.amazon.com/Polarized-Adap...0+volt+adapter

Macy's luggage & American Tourister outlet stores (in Secaucus) have them too - a bit pricer, perhaps. If you have a Dollar Store or 99 cents store (as in NYC,) check the electrical/electronic gadgets section, they have inexpensive adapters that fit over your iOS chargers.

For upscale hotels in PEK, PVG & CAN, etc. - as others said, they usually have at least 1 outlet marked for US plugs, not necessary 110 volts but the iOS charger-adapter together will work. Mini/micro-usb & iOS/30 pins cables are inexpensive and sold in CN at a tiny fraction of US prices. You can also shop eBay as oversea sellers ship free or inexpensively and delivered in usually under 2 weeks with best prices.

Many of the bigger malls in China selling mobile devices, computers & accessories generally will stock these adapters - dirt cheap and worked.

To travel with fewer gadgets & adapters - pick up something like this that provide 2 or 3 USB charger port (1 hi-power @ 2Amp and 1 for regular .5Amp or .7Amp for digital cameras or cellular devices)
http://www.amazon.com/PowerGen-Charg...p_p_img_2_VJG4
Very handy for domestic travel use - combined with plug adapter above, fit for worldwide travel. Without calling down to housekeeping late night or waiting for them to bring one/trip to the front desk, etc.

Facetime usually works from within China as long as you get a quality connection & decent speed, otherwise video could drop - I do recommend pre-installing Skype on the iPad and test it at home first, as WiFi calling is free and it works across different platforms (iOS, Android & PC/desktop, etc.) Backup apps as extra "insurance" just in case FT isn't working for whatever reasons.