Plant derived porous graphene nanosheets for efficient CO2capture

Abstract

There is an urgent need for the mitigation of climate change through CO2 reduction technologies. In this work, we demonstrate a novel method for production of porous graphene-like nanosheets (PGLNS) from the lignocellulosic fiber of oil palm empty fruit bunches (EFB) by a thermal graphitization technique for efficient CO2 capture. We used a wide range of microscopic and spectroscopic techniques to provide insights into the morphological and structural characteristics of the synthesized PGLNS (with d-spacing of ∼0.35 nm and pore size of <1 nm) obtained from the EFB biomass. The PGLNS show excellent performance as adsorbents for post-combustion CO2 capture. At 25 °C and 1 bar pressure, the maximum CO2 uptake was 2.43 mmol g−1 which is considerably higher than other competitive CO2 adsorbents, including zeolite, activated carbon and some metal organic frameworks. The selectivity of the PGLNS for CO2 over N2 (SCO2/N2 = 18.7), computed from single component isotherms at conditions pertinent to post-combustion applications, is also much higher than that of most of the previously reported adsorbents. Moreover, the significantly low isosteric heat of adsorption (∼21 kJ mol−1) revealed the possibility of desorbing CO2 and regenerating the PGLNS for their repeated use at a much lower energy penalty.