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

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.