High phase-purity 1T′-MoS2- and 1T′-MoSe2-layered crystals

Abstract

Phase control plays an important role in the precise synthesis of inorganic materials, as the phase structure has a profound influence on properties such as conductivity and chemical stability. Phase-controlled preparation has been challenging for the metallic-phase group-VI transition metal dichalcogenides (the transition metals are Mo and W, and the chalcogens are S, Se and Te), which show better performance in electrocatalysis than their semiconducting counterparts. Here, we report the large-scale preparation of micrometre-sized metallic-phase 1T'-MoX (X = S, Se)-layered bulk crystals in high purity. We reveal that 1T'-MoS crystals feature a distorted octahedral coordination structure and are convertible to 2H-MoS following thermal annealing or laser irradiation. Electrochemical measurements show that the basal plane of 1T'-MoS is much more active than that of 2H-MoS for the electrocatalytic hydrogen evolution reaction in an acidic medium.

Ultrathin Ni(0)‐Embedded Ni(OH)2 Heterostructured Nanosheets with Enhanced Electrochemical Overall Water Splitting

“…As a clean renewable energy source, hydrogen generation by electrochemical water splitting is attracting great attention . Nevertheless, one of the main technological obstacles for the massive hydrogen production is to develop cost‐efficient electrocatalysts . Noble metal‐based nanomaterials have been reported with superior performance in electrochemical overall water splitting.…”

Hatted 1T/2H‐Phase MoS2 on Ni3S2 Nanorods for Efficient Overall Water Splitting in Alkaline Media

“…The Mo 3d spectrum showedM o 4 + peaks at 228.8 and 232.6 eV,w hich were assigned to the 3d 5/2 and 3d 3/2 components, respectively,o f1 T-MoS 2 . [47][48][49] Clearly,t he peaks of Mo 3d 5/2 and Mo 3d 3/2 were shiftedt oh igherb inding energy owing to the existence of strong electronic interactions between Ni 3 S 2 and MoS 2 . [47][48][49] Clearly,t he peaks of Mo 3d 5/2 and Mo 3d 3/2 were shiftedt oh igherb inding energy owing to the existence of strong electronic interactions between Ni 3 S 2 and MoS 2 .…”

Ultrasonic‐Ball Milling: A Novel Strategy to Prepare Large‐Size Ultrathin 2D Materials

“…[ 24,26,27 ] Approximately, the main characteristic peaks of exfoliated graphene, MoS 2 and WS 2 nanosheets shown in Figure 3b–d demonstrate similar slightly shift due to the expanded layer spacings, which ensure the proposed exfoliation method an effective strategy in peeling off 2D materials. [ 28,29 ] For h‐BNNS, graphene and WS 2 nanosheet, their peak intensities increase and half peak widths reduce after exfoliation, demonstrating a better crystallinity and more exposure of characteristic crystal planes. [ 27 ] The above characteristics of MoS 2 nanosheet are not obvious, which may be due to a decrease of crystallinity caused by slight agglomeration of the MoS 2 nanosheet during the filtration process.…”