Size-selective electrodeposition of meso-scale metal particles: a general method

Metal nano- and microparticles that are narrowly dispersed in diameter can be electrodeposited on graphite basal plane surfaces using the two-step method: First, a voltage pulse with a duration of 5 ms and an overpotential, eta = - 500 mV was used to nucleate metal particles on the graphite surface. Then, a growth pulse with an overpotential, ij, of - 20 to - 250 mV was applied to grow the metal particles obtained in step 1 to the desired final diameter. For a variety of metals, including silver, gold, platinum, molybdenum, and nickel, this 'slow-growth' method yielded dispersions of particles ranging in diameter from 50 nm to 2 mum having a relative standard deviation (RSDdia = sigma (dia)/< dia >) as low as 7%. (C) 2001 Elsevier Science Ltd. All rights reserved.