Interface Engineering in Two‐Dimensional Heterostructures: Towards an Advanced Catalyst for Ullmann Couplings

Abstract

The design of advanced catalysts for organic reactions is of profound significance. During such processes, electrophilicity and nucleophilicity play vital roles in the activation of chemical bonds and ultimately speed up organic reactions. Herein, we demonstrate a new way to regulate the electro- and nucleophilicity of catalysts for organic transformations. Interface engineering in two-dimensional heteronanostructures triggered electron transfer across the interface. The catalyst was thus rendered more electropositive, which led to superior performance in Ullmann reactions. In the presence of the engineered 2D Cu2 S/MoS2 heteronanostructure, the coupling of iodobenzene and para-chlorophenol gave the desired product in 92 % yield under mild conditions (100 °C). Furthermore, the catalyst exhibited excellent stability as well as high recyclability with a yield of 89 % after five cycles. We propose that interface engineering could be widely employed for the development of new catalysts for organic reactions.

Nitrogen‐Doped Cu2S/MoS2 Heterojunction Nanorod Arrays on Copper Foam for Efficient Hydrogen Evolution Reaction

“…In enlarged TEM image(Figure f), the Cu 2 S nanorod could be clearly identified with a lattice fringe of 0.24 nm in consistent with the Cu 2 S crystalline plane (012). Interplanar spacing of 0.27 nm could be also observed, which was consistent with the spacing of crystalline plane (100) of hexagonal MoS 2 nanosheets ,. In addition, there existed the abnormal structures between both the crystalline lattice patterns of Cu 2 S and MoS 2 in the dashed area.…”

“…Furthermore, the interfacial effects were investigated by the UV‐Vis spectral method (Figure f). Compared to Cu 2 S/CF, the absorption edge of Cu 2 S/MoS 2 /CF showed a red shift in the combined system indicated substantial band‐gap narrowing, which provides the evidence for electronic interactions between Cu 2 S and MoS 2 heterojunction interface . Based on the XPS and UV‐Vis data, it can be assumed that N doped MoS 2 nanosheets were coated on Cu 2 S nanorod, producing strong interfacial effects via heterojunction structure.…”

“…N doping effect manufactures abundant defect sites and the unfolded MoS 2 nanosheet provides high electrochemically active surface area. These factors endowed the enhanced electrocatalytic activity …”

Optical and Electrical Enhancement of Hydrogen Evolution by MoS2@MoO3 Core–Shell Nanowires with Designed Tunable Plasmon Resonance

“…As shown in Figure a, after immobilization of MoS 2 onto MoO 3 , the in‐plane vibration mode E 2g 1 and the out‐of‐plane vibration mode A 1g of MoS 2 in the hybrid nanostructures have been redshifted compared with those of the pristine MoS 2 (from 375 to 381 cm −1 for the E 2g 1 mode and from 401 to 405 cm −1 for the A 1g mode). This shift is attributed to the in situ growth of MoS 2 , changing the primitive vibration mode of the MoS bonds . With the increase of hydrogen reduction time, a shift in the Raman modes (from 381 to 386 cm −1 for E 2g 1 and from 405 to 409 cm −1 for A 1g ) can be noticed, which are possibly attributed to strain and stress on the interface between the MoO 3 and the MoS 2 .…”

“…Transition‐metal chalcogenides (TMCs), with rich electron configurations leading to controllable electronic structures, have undergone major developments in the pursuit of novel photocatalyst designs . However, the limited utilization of visible light and the high recombination ratio of photoinduced electron–hole pairs in layered materials restrict the performance of TMCs in photocatalysis systems.…”