php xpath按属性获取特定元素

I'm trying to get an element by an specific attribute ("data-image-id").

I got this:

$dom = new DOMDocument;
@$dom->loadHTML($html);
$xpath = new DOMXpath($dom);
$links = $xpath->query('//div[@data-image-id]/@data-image-id');
die(var_dump($links));

but I got the following:

object(DOMNodeList)#3 (1) { ["length"]=> int(0) } 

I just want to get all elements with the attribute "image-data-id".

What am I doing wrong?