Produção e caracterização de biocarvões contendo óxido de grafeno para incorporação de boro

Abstract

Biochars (BC) are carbonaceous materials derived from the biomass pyrolysis process aiming to improve soil quality and are been studied for various industry applications. Some properties presented by BC have awakened interest in the agricultural industry due to their resistance to decomposition and capacity to actuate as a matrix for nutrient storage, promoting improvements in the quality and productivity in agriculture. The high coffee production in the southern region of Minas Gerais has called attention due to the large amounts of generated waste. This waste, when not treated and stabilized, returns to the biogeochemical carbon cycle, emitting gases that contribute to the greenhouse effect. In this sense, thermal stabilization of this material is necessary to add value to the final product, being able to develop properties that facilitate the aggregation of micronutrients in its structure. From this perspective, this work aims to produce and characterize BC obtained from thermally treated biomass of coffee husk surface-functionalized with graphene oxide (GO), under an inert controlled atmosphere in different pyrolysis temperatures ranges, aiming the retention of boron micronutrient. For this purpose, GO was synthesized and used in surface functionalization biomass of coffee husk for BC in four temperatures (400, 500, 750 and 900 oC). The materials produced, treated or not with boric acid, were characterized by thermogravimetric analysis, scanning electron microscopy, Raman and infrared spectroscopies. The results of the characterization analysis indicated structural changes in BC caused by the treatment with GO and boric acid. Changes in crystallite sizes and thermal stability of the material were observed, indication changes induced by existing interactions between BC and GO, as well as interaction GO and boron atom in the structure BC.