Dynamic path issue

Hi, I want to create a dynamic path in function.php but the path had changed like http://https//vidyapeeth.aphroecs.com/aadharshila-fraternity/welcome-to-aadharshila/
This is the code
//Create shortcode for getting home url
function get_base_url() {
$home_url = home_url();
return $home_url;
}
// register shortcode
add_shortcode('base-url', 'get_base_url');