function mb_ucfirst($str){
    $str = trim($str);
    $firstChar = mb_substr($str, 0 , 1 ,'UTF-8');
    $firstChar = mb_strtoupper($firstChar, 'UTF-8');
    return $firstChar . mb_substr($str, 1, strlen($str) - 1, 'UTF-8');
}

happy coding