Enhancing CO₂ capture through innovating monolithic graphene oxide frameworks

The advancement and engineering of novel crystalline materials is facilitated through the utilization of innovative porous crystalline structures, established via KOH-treated monolithic graphene oxide frameworks. These materials exhibit remarkable and versatile characteristics for both functional exploration and applications within the realm of CO₂ capture. In this comprehensive study, we have synthesized monolithic reduced graphene oxide-based adsorbents through a meticulous self-assembly process involving different mass ratios of GO/malic acid (MaA) (1:0.250, 1:0.500, and 1:1 by weight). Building upon this foundation, we further modified MGO 0.250 through KOH-treatment by chloroacetic acid method, leading to the creation of MGO 0.250_KOH, which was subjected to CO₂ capture assessments. The comprehensive investigation encompassed an array of parameters including morphology, specific surface area, crystal defects, functional group identification, and CO₂ capture efficiency. Employing a combination of FT-IR, XRD, Raman, BET, SEM, HR-TEM, and XPS techniques, the study revealed profound insights. Particularly notable was the observation that the MGO 0.250_KOH adsorbent exhibited an exceptional CO₂ capture performance, leading to a significant enhancement of the CO₂ capture capacity from 1.69 mmol g^-1 to 2.35 mmol g^-1 at standard conditions of 25 °C and 1 bar pressure. This performance enhancement was concomitant with an augmentation in surface area, elevating from 287.93 to 419.75 m² g^-1 (a nearly 1.5-fold increase compared to MGO 1.000 with a surface area of 287.93 m² g^-1). The monolithic adsorbent demonstrated a commendable production yield of 82.92%, along with an impressive regenerability of 98.80% at 100 °C. Additionally, adsorbent's proficiency in CO₂ adsorption, rendering it a promising candidate for post-combustion CO₂ capture applications. These findings collectively underscore the capacity adsorbents to significantly amplify CO₂ capture capabilities. The viability of employing this strategy as an uncomplicated pre-treatment technique in various industrial sectors is a plausible prospect, given the study's outcomes.