function to remove duplicates from different sheets

I have this code that do that task of extracting unique lists from multi sheets..

Sub UniqueId()
For j = 2 To Sheets.Count
    With Sheets(j)
    Set deb = .Range("G4:G" & .Range("G" & .Rows.Count).End(xlUp).Row)
        For i = 1 To deb.Rows.Count
            If InStr(raj & ",", "," & deb(i, 1) & ",") = 0 Then raj = raj & "," & deb(i, 1)
        Next i
    End With
Next j
 
    roy = Split(Mid(raj, 2), ",")
    Sheets(1).Range("C4").Resize(UBound(roy) + 1) = Application.Transpose(roy)
End Sub

But it extracts a blank cell which is considered as a unique value.. I want to get rid of that blank unique value