Effects of morphology and crystallinity of MoS₂ nanocrystals on the catalytic reduction of p-nitrophenol

p-Nitrophenol (p-NP), a well-known organic pollutant in industrial and agricultural wastewater, is difficult to degrade. Therefore, an exploiting efficient and economical reductant is of great significance for environmental remediation and human health. Herein, MoS₂ nanocrystals with different morphologies were successfully prepared by a simple hydrothermal method in the mixed solution of ethylenediamine and ethylene glycol. The morphology can be readily controlled by tuning the volume ratio of ethylenediamine to the solvent (R). Moreover, well-crystallized MoS₂ nanocrystals were developed by the following heat treatment process. The as-prepared MoS₂ nanocrystals were employed as catalysts for the reduction of toxic p-NP to industrially beneficial p-aminophenol (p-AP). It was clearly revealed that both the morphology and crystallinity play critical roles in the catalytic reduction efficiency. Among the MoS₂ samples, the optimized R75 sample with a rough surface exhibits the highest rate constant of k_app = 0.3906 min⁻¹ for the reduction of p-NP, while improved crystallinity will decrease the catalytic efficiency. These novel findings can promote the development of a new non-noble metal catalyst which can be used for wastewater reductive treatment.