Effects of capping layers on the photoelectrochemical property of silver nanoparticle-modified indium–tin-oxide electrode

Photoelectrochemical properties of indium–tin-oxide (ITO) substrate modified with silver nanoparticles (AgNPs) and effects of surface capping layer of AgNP were investigated in the water/acetonitrile (H2O/MeCN) electrolyte solutions with the presence of oxygen as an electron acceptor. The modified ITO substrate showed photocurrent response mainly driven by the photoinduced electron transfer from ITO substrate to AgNPs. In addition, its photoelectrochemical property significantly depended on the solvent composition of electrolyte solution which was in correlation with surface status of AgNPs. Combination of photoelectrochemical measurements and spectroscopic analysis suggested that presence of considerable amount of MeCN in the electrolyte solution triggered partial displacement of capping citrate ions to activate photocurrent generation.

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► Photoelectrochemical properties of ITO substrate modified with AgNPwere examined.
► Acetonitrile functioned as a deprotecting agent ofcitrate capping layer.
► Electroninjection from excited ITO to AgNPinitiated the photocurrent generation.
► The photocurrent response andsurface status of AgNP were deeply correlated.