Hierarchical Porous Nitrogen-Doped Carbon Nanosheets Modified with Sodium Hydroxide for Efficient Removal of Hydrogen Sulfide at Room Temperature

Abstract

The efficient catalytic oxidation of H₂S under ambient conditions underscores the urgency of designing carbon-based catalysts that exhibit superior catalytic activity coupled with substantial product storage capability. This work introduces a facile and scalable approach to synthesize a nitrogen-doped hierarchical porous carbon nanosheet, which was rigorously evaluated for its efficacy in the catalytic oxidation of H₂S after impregnation with NaOH. It is noteworthy that the impregnation with NaOH promotes the dissociation of H₂S. The nitrogen doping profoundly elevates the defect degree and oxygen vacancy content, which, in turn, enhances the catalytic activity. The unique nanosheet morphology and well-developed pore structure not only improve the mass transfer kinetics but also provide sufficient space for the diffusion of H₂S and storage of products. Consequently, the breakthrough capacity of the nitrogen-doped mesoporous carbon nanosheet catalyst has an astonishing value of 10.94 g H₂S/g-catalyst. Drawing upon comprehensive experimental insights and detailed characterization analyses, we propose a plausible mechanism for the catalytic oxidation of H₂S at room temperature on the NaOH-loaded nitrogen-doped carbon nanosheet catalysts and a deactivation mechanism for the catalysts. This research presents a promising strategy for developing high-performance nitrogen-doped carbon catalysts with potential applications in H₂S removal, thereby advancing the field of environmental catalysis.