Antioxidants for sperm health

My husband and I have been trying for a year with no luck. I went to my obgyn today and one of the things she said is she knows the urologist always puts his patients on an antioxidant for sperm health. She wasn't sure which one and just recommended googling it to find one to get started on it while we wait. She said they should all be pretty similar but I was wondering if any of your husbands take this and have a suggestion on what brand/type to take?