How much energy is required to release one photon?
The energy required to release a photon depends on its frequency.
The energy of a photon is related to its frequency or wavelength. The energy
Photons are commonly emitted by electrons in atoms. Electrons can only occupy certain discrete energy levels. When an atom is in an excited state, one or more of its electrons are pushed into a higher energy level. This requires energy. When an electron drops into a lower energy level it releases the energy by releasing a photon at a precise frequency which corresponds to the different between the two energy levels.
Photons can have any frequency from the very low frequency radio waves, through visible light up to the very high frequency gamma rays.
Lower frequency photons are emitted by electrons losing energy. Gamma rays are emitted when an atomic nucleus needs to lose energy.
Hence a photon can be released by any amount of energy.