Silver deposition on chemically treated carbon monolith

Abstract

Carbon monolith was treated with HNO3, KOH and H2O2. Effects of these treatments on the surface functional groups and on the amount of silver deposited on the CM surface were studied by temperature programmed desorption (TPD) and atomic absorption spectrometry (AAS). As a result of chemical treatment there was an increase in the amount of surface oxygen complexes. The increase in the amount of silver deposit is proportional to the amount of surface groups that produce CO under decomposition. However, the high amount of CO groups, decomposing above 600°C, induces the smaller Ag crystallite size. Therefore, the high temperature CO evolving oxides are, most likely, the initial centers for Ag deposition.

Karbon monolit (KM) tretiran je rastvorima HNO3, KOH i H2O2. Uticaj tretmana na površinske funkcionalne grupe i na količinu izdvojenog srebra na površini KM-a ispitivan je temperaturski programiranom desorpcijom (TPD) i atomskom apsorpcionom spektrometrijom (AAS). Tretman svim navedenim rastvorima dovodi do povećanja količine površinskih kiseoničnih grupa, a količina izdvojenog srebra je proporcionalna količini grupa koje dekompozicijom daju CO. Visoko-temperaturske fenolne, karbonilne, etarske i hinonske grupe, koje dekompozicijom daju CO iznad 600°C, predstavljaju inicijalne centre za rast kristalita Ag, a veličina kristalita srebra je obrnuto proporcionalna koncentraciji ovih visoko-temperaturskih grupa na površini KM.