WORK FUNCTION OF METALLIC NANOPARTICLE AS A FUNCTION OF ITS RADIUS AND CHARGE

An analytical expression was obtained for the variation of the work function of a metallic nanoparticle in comparison with its value for the flat surface of the bulk corresponding metal as a function of the nanoparticle radius and its charge. It was demonstrated, that the work function for electroneutral nanoparticles starts to diminish essentially for the small radii of 2 nm and less. However, even a single elementary charge, placed on nanoparticle, makes the variation of the work function essential for its radius of 10 nm order, and this effect increases with the increase of the charge. The negative charge placed on nanoparticle causes the decrease of its work function, and the positive one – its increase. The perspectives for the use of an effect under examination in chemical and biological sensing are discussed.