可捕获的致命错误:类stdClass的对象无法转换为字符串

I get above error on my php code. I get the error for the following line.

 echo '<tr><td style="width:400px;padding:5px;"></td><td style="width:300px;padding:5px;"><img src="'.$image_folder.$value->$value->prfil_img .'" /></td></tr>';

I know I haven't use strings properly here. Either double quotation or single quotation have not been used properly. However, I can't figure it out.

Can anybody help me?

This looks wrong:

$image_folder.$value->$value->prfil_img

You probably meant:

$image_folder . $value->prfil_img