PHP mb_convert_encoding不适用于查询

I am trying to generate a query string. Characters show up as different queries.

Php version:7.3.2

Function

$D->query = '';

if ($this->query('x')) {

    $D->query = mb_convert_encoding($this->query('x'), 'UTF-8');
}

Result for #Синодал:

#%D0%A1%D0%B8%D0%BD%D0%BE%D0%B4%D0%B0%D0%BB

The string is urlencoded, you need to simply urldecode first, from there you can do any encoding changes:

$decoded = urldecode($this->query(“x”));
$D->query = mb_convert_encoding($decoded, “utf-8”);