Photoinduced thermal copper reduction onto gold nanocrystals under potentiostatic control.
We study the photoreduction of adsorbed copper ions onto Au nanoparticles, on an indium tin oxide (ITO) electrode in an aqueous electrochemical cell, as a function of applied voltage and laser intensity. The photocurrent is a nonlinear function of laser intensity and increases sharply with cathodic voltage in the underpotential deposition region. The photoreduction is attributed to laser heating of the Au nanoparticles rather than "hot electron" processes. Numerical simulation of the Butler-Volmer kinetic equation using experimental parameters predicts a several orders of magnitude increase in current for a temperature rise of a few Kelvin.
Redmond
Peter L
PL
Chemistry Department, Columbia University, New York, New York 10027, USA. plr2001@columbia.edu
Walter
Erich C
EC
Brus
Louis E
LE
D000327:Adsorption; D003300:Copper / Q000737:chemistry* / Q000528:radiation effects*; D004563:Electrochemistry; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D008027:Light; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D010777:Photochemistry; D011199:Potentiometry; D012680:Sensitivity and Specificity; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D017971:Tin Compounds / Q000737:chemistry; D014867:Water / Q000737:chemistry
D017971:Tin Compounds; D014867:Water; C109984:indium tin oxide; D006046:Gold; D003300:Copper