php - "Â " character showing up instead of " "

I found this thread which describes my issue pretty well and this answer describes my issue exactly.

The non-breaking space character is byte 0xA0 is ISO-8859-1; when encoded to UTF-8 it'd be 0xC2,0xA0, which, if you (incorrectly) view it as ISO-8859-1 comes out as "Â ". That includes a trailing nbsp...

However, I have managed to track my issue down to a function I use to wrap image tags in divs.

function img_format($str)
{
    $doc = new DOMDocument();
    @$doc->loadHTML($str);     // <-- Bonus points for the explaination of the @

    // $tags object
    $tags = $doc->getElementsByTagName('img');

    foreach ($tags as $tag) {


        $div = $doc->createElement('div');
        $div->setAttribute('class','inner-copy');
        $tag->parentNode->insertBefore($div, $tag);
        $div->appendChild($tag);

        $tag->setAttribute('class', 'inner-img');
    }

    $str = $doc->saveHTML();


    return $str;
}

Quite simply, how can I fix this issue within this function?

I understand using;

will fix this issue, but there is obviously something I'm overlooking within the function itself.

I've tried;

$dom->validateOnParse = true;

To no avail. (I don't quite know what that does anyway)

Answer

Found it!

@$doc->loadHTML(mb_convert_encoding($str, 'HTML-ENTITIES', 'UTF-8'));

This answer explains the issue and gives the work around above;

DOMDocument::loadHTML will treat your string as being in ISO-8859-1 unless you tell it otherwise. This results in UTF-8 strings being interpreted incorrectly.