Visa requirement for the duration of stay for Pakistani and Australian citizen.

Hi I am an Australian passport holder and have a national identity card to enter Pakistan. But my wife is a Pakistani passport holder and we might plan to visit Pakistan using air china from Melbourne in end of November 2017. There is 10:30hrs time gap for the connection flight flight to Pakistan (karachi) from CHINA CAPITAL AIRPORT. And likewise when we will return to Melbourne in mid January 2018. There is gap of 15hrs to connection flight to Australia (Melbourne ) from china.
My question is there any visa required for both us to stay in the airport before boarding the connection flights. Hope to hear from your soon. Thanks.
Kind Regards,
Abdul