Hopefully it is just your 9V batteries that are dead, not the IR LEDs burned out.
You need a half-decent battery. Six AAA size NI-MA cells produce about 7.5V.
It can drive four strings of 5 IR LEDs in series with 51 ohms current-limiting resistors that limits the current to 29mA. The total battery current is 116mA and it should last for 7 hours.
You should buy name-brand parts at a reputable electronics parts distributor like Digikey or Newark. They have detailed datasheets.