A first-principles study on Ni-decorated MoS2 for efficient formaldehyde degradation over a wide temperature range

Abstract

The development of a high-efficiency, low-cost, and environmentally friendly catalyst for formaldehyde degradation is crucial for addressing the issue of indoor formaldehyde pollution. Given that modern individuals spend over 90% of their time indoors, effectively tackling indoor formaldehyde pollution holds significant importance. Therefore, this paper proposes an efficient catalyst for formaldehyde degradation: surface modification of MoS₂ by single-atom Ni, which can convert formaldehyde into harmless H₂O and CO₂. The DFT method is employed to systematically investigate the oxidative degradation pathways of formaldehyde on the surface of Ni-doped MoS₂. The research focuses on two common oxidative degradation pathways in both the L–H mechanism and E–R mechanism. Our findings demonstrate that these four reaction paths occur spontaneously within the temperature range of 300–800 K with a reaction equilibrium constant greater than 10⁵. Moreover, even under extreme temperature conditions (100 K), the reaction rate remains favorable. Furthermore, our findings indicate that the minimum activation energy is merely 0.91 eV and H₂O and CO₂ only need to overcome an energy barrier of 0.71 eV for desorption from the catalyst surface. This substantiates its potential application both in indoor environments and under extreme temperature conditions. This theoretical research provides innovative ideas and strategies for effectively oxidizing formaldehyde.