Optimization of the use of Boron Derivate as Activating Agent for Hierarchical Pore Formation in Activated Carbon Structure

Abstract

In this study, the effects of boron-derived chemicals such as ammonium biborate (ABB), borax and boric acid on the size and volume distribution of the pores formed in the structure of activated carbon in the production of activated carbon from agricultural waste pistachio shells were examined. The effect of production conditions such as type of activating agent (ABB, Borax, Boric acid), activating agent rate (10%, 20%, 30%, 40% and 50%), holding time in the activating agent solution (1 day, 2 days, 3 days, 4 days and 5 days) and carbonization temperature (700 ^oC, 750 ^oC, 800 ^oC, 850 ^oC and 900 ^oC) on this distribution was also examined in terms of TG-DTA, FT-IR, SEM, BET surface area and BJH pore volume, pore surface area, volume distribution and pore diameter. According to the results obtained, peanut shells containing pores with an average diameter of 1.122 nm and a volume of 0.033 cc g^-1 turned into AC with a volume of 7.255 cc g^-1, a pore size of 42.52 nm. The highest pore surface area was observed as 300 m² g^-1 when 20% activating agent was used. As a result of waiting for 2 days, an expansion of the pore size up to 60 nm was observed. While the amount of ACs obtained increased to 9 cc g^-1 in the range of 10-15 nm at 800 ^oC, a more hierarchical structure in terms of micro and mesoporosity and even macroporosity was obtained at 850 ^oC. As a result, while AC with high micropore density was obtained from peanut shells with the use of ammonium biborate, both micro-, meso- and macro-sized pores were obtained with the use of boric acid. In addition, the use of 20%, 2 days and 850 ^oC production conditions was seen to support this hierarchy.