Síntese, caracterização e aplicação de Bi2O2CO3 na redução eletroquímica de CO2 em HCOOH e degradação de poluentes

Abstract

The increasing emission of CO2 into the atmosphere from the burning of fossil fuels is one of the main environmental challenges that humanity has been facing and it is necessary to create new technologies to mitigate the problem. This work investigated the effect of bismuth oxycarbonate (Bi2O2CO3) exfoliation as an electrocatalyst for the reduction of CO2 into formic acid (HCOOH) and compared it with commercial Bi2O2CO3 synthesized at different temperatures. The morphology and catalytic performance of a commercial sample of Bi2O2CO3, a sample exfoliated by TBAOH and two samples synthesized by different routes were analyzed. The samples were characterized by different characterization methods (FTIR, SEM, XRD, Raman and TGA). The study initially evaluated the photocatalytic activity of Bi2O2CO3 in the degradation of dyes (Rhodamine-B and Methylene Blue), highlighting the exfoliated sample, which degraded approximately 40% of Rhodamine-B, and presented a superior performance to the commercial sample. The Bi2O2CO3 samples were applied in the electrochemical reduction of CO2 in an electrochemical flow cell, achieving a current density of -160 mA/cm-2 and a Faradaic efficiency greater than 96% in the production of formic acid. The sample with the best performance was the exfoliated one, followed by the commercial one and those synthesized by Route I and Route II. Thus, the great catalytic potential of the Bi2O2CO3 samples was observed both in the reduction of CO2 and in the degradation of organic pollutants, being a promising strategy for the sustainable conversion of CO2 into products with higher added value, thus aligning with the global goals of pollutant reduction and valorization of industrial waste.