Tailoring the structure and energy level over transition-metal doped MoS₂towards enhancing 4-nitrophenol reduction reaction

Exploring high-efficiency, robust and cost-effective catalysts for the reduction of 4-nitrophenol (4-NP) to 4-Aminophenol (4-AP) is greatly desirable. Herein, a series of transition-metal doped MoS2 (M-MoS2, M = Mn, Fe, Co, Ni, Cu, Zn) with expanded interlayer spacing are fabricated by one-step solvothermal strategy. Notably, nickel doped molybdenum disulfide (Ni-MoS2) is found to exhibit prominent catalytic activity with an apparent rate constant (K) of 1.09 min-1 and excellent stability over six continuous runs of recycling experiments. The results demonstrate that the expanded interlayer spacing (0.94 nm) can increase the active sites of reactant absorption, and Ni dopants can lower the energy level (d-band center) to facilitate the desorption of H. Thus, the catalytic activity of Ni-MoS2 is enhanced by synergistically structural and energy level modulation. This study offers an effective strategy to design transition metal sulfides with higher catalytic reactivity for the environment-related catalysis processes.