Question

why the second ionization energy is more than first ionization energy for any element

Answer 1

the energy required to remove first electron from the outermost orbit or shell of a neutral gaseous atom is called first ionization energy.
  the energy required to remove an electron from uni-positive ion is called 2nd ionization energy.
 the 2nd I.E is greater then the 1st I.E. On  removing an electron from an atom the uni-positive ion formed will have more effective nuclear charge than the neutral atom. at the same time increases the nuclear attraction on the electron in the outer shells. as a result more energy is required is required to remove an electron from an uni-positive ion.hence the 2nd I.E greater than the 1st I.E 

Answer 2

when the first electron is released from an isolated gaseous atom, the number of electron of the atom decreases by 1.
The nuclear charge on the electrons increases and the electrons are held more tightly. Now more energy is required to remove another electron there increasing the ionization energy