I want to make my array unique in php

Question

please look at below output

[
    {
        "id": "8",
        "title": "windows",
        "subtitle": "win"
    },
    {
        "id": "8",
        "title": "windows",
        "subtitle": "win"
    }
]

I only want to display

[
    {
        "id": "8",
        "title": "windows",
        "subtitle": "win"
    }
]

how can i do this? I have tried array_unique() but it is not giving me proper results.

Thanks in advance! please help me.