ESTUDO DE PARTICULAS DE ZnO PURO E DOPADO COM Ag APLICADO NA DEGRADAÇÃO DA CAFEÍNA: INFLUÊNCIA DO PH

Caffeine, when detected in drinking water and surface water, is classified as a contaminant of emerging concern. This designation includes substances whose effects on living beings are little known, and there is no legislation that sets a maximum discharge limit. Heterogeneous photocatalysis has proven to be a technique capable of degrading organic compounds through the formation of reactive intermediates. Some of the factors that influence the photocatalytic reaction are pH, a parameter that can alter the surface of the catalyst, whether or not this change is favorable for the adsorption of pollutant molecules and subsequent photocatalytic reaction. This research evaluated the influence of pH on the photocatalytic degradation of caffeine using pure ZnO and 5% Ag as a catalyst. It was possible to verify that, in general, in a basic reaction medium the kinetics of degradation of the pollutant were superior in relation to the acidic medium, however, for the three different pH values, at the end of the reaction the degradation of caffeine was above 98% for both catalysts.