The aim of this work is to exploit the negative electron affinity of the surface of hydrogenated diamond combined with the excitation of conduction band electrons to induce emission of electrons following the interaction with visible light. Diamond is a very wide band gap semiconductor and therefore interacts weakly with visible light. However, we show that by combining plasmonic nanoparticles with diamond it is possible to excite electrons into the conduction band of the diamond through a multistep process involving at least two visible light photons.