Mechanistic and Experimental Study of the Formation of MoS₂/HKUST-1 Core-Shell Composites on MoS₂ Quantum Dots with an Enhanced CO₂ Adsorption Capacity

In this study, a new "one-pot" synthesis method was developed for the fabrication of HKUST-1 on MoS₂ quantum dots (QDs) to form a core-shell structure. It is proved that the HKUST-1 self-Assembles on MoS₂ QDs to form a core-shell structure, which exhibits a high surface area of 1638.9 m²/g and enhances CO₂ uptake to 4.64 mmol/g as compared with HKUST-1 alone. The density functional theory (DFT) calculations revealed that the growth of HKUST-1 on MoS₂ QDs starts from the adsorption of Cu²⁺ cations on the MoS₂(001), followed by the Cu²⁺ cations bonding with trimesic acid (TMA) anions. In addition, the interactions between a CO₂ molecule and the (MoS₂ + SBU) (secondary building unit = SBU) unit were studied using DFT calculations to show the mechanism of CO₂ adsorption on the MoS₂/HKUST-1 core-shell composite. It is found that the MoS₂ QDs induce stronger electrostatic forces on CO₂ than HKUST-1 alone, which subsequently contributes to enhancing the adsorption of CO₂ on the MoS₂/HKUST-1 core-shell composite.