Threshold frequency for platinum is 1.3$\times$10¹⁵ sec^-1. Platinum shows photo electric effect when exposed to 

Threshold frequency of platinum falls in the U V range ( 8$\times$10¹⁴ s^-1 - 3 $\times$10¹⁶ s ^-1). Platinum display the photo electric effect when exposed to 

U V light  pt frequency $⩾$ 1.3 $\times$10¹⁵ s^-1

Frequency of I R light is in the range of 10¹² s^-1 - 4$\times$ 10¹⁴ s^-1 lesser the threshold frequency of platinum, will not show photo electric effect.