Waste biomass-derived oxygen and nitrogen co-doped porous carbon/MgO composites as superior acetone adsorbent: Experimental and DFT study on the adsorption behavior.

• Oxygen and nitrogen co-doped porous carbon/MgO (ONPC@MgO) composites were synthesized. • Acetone is captured by O/N functional groups and MgO by monolayer adsorption at low pressure. • Acetone is adsorbed on the surface of carbon and MgO by multilayer adsorption at high pressure. • Adsorption mechanism between acetone and ONPC@MgO composites is elucidated by experimental and DFT methods. The amount of anthropogenic volatile organic compounds (VOCs) emission keeps increasing worldwide, and it urges the development of VOC emission reduction technology. Efficient and environmentally friendly adsorption technology is receiving more interest, and carbon-based materials have attracted enormous attention for VOC capture. However, the poor adsorption capacity and cycling stability still hinder their application. Moreover, the mechanism of adsorption behavior between functionalized carbon surfaces and VOCs has not been investigated in detail. Herein, we report a sustainable and cost-effective method for the anchoring of the MgO nanoparticle onto O/N co-doped porous carbon derived from waste biomass (denoted as MgO@ONPC). The optimized 7%MgO@ONPC composite exhibited an exceedingly high acetone adsorption capacity (859 mg g−1 at 25 °C, 18 kPa) and excellent cycling stability (95.2% capacity retention over 10 cycles). Acetone dynamic breakthrough tests showed that the adsorption capacity of 7%MgO@ONPC composite at 10% breakthrough level (10% BT) and 100% BT was 384 and 508 mg g−1, respectively (in terms of PC: 3.9 × 10−3 and 5.2 × 10−2 mol kg−1 Pa−1, respectively). Isotherm model fitting and quantum chemistry calculation studies indicated O/N functional groups and MgO nanoparticles can significantly improve the acetone monolayer adsorption at low relative pressures due to hydrogen bonds and electrostatic interaction. Highly active MgO nanoparticles and pore structure characteristics are found to be determinative factors for acetone adsorption at high relative pressure. [ABSTRACT FROM AUTHOR]