The discovery of moiré superlattices (MSLs) opened an era in the research of ‘twistronics’. Engineering MSLs and realizing unique emergent properties are key challenges. Herein, we demonstrate an effective synthetic strategy to fabricate MSLs based on mechanical flexibility of WS₂ nanobelts by a facile one-step hydrothermal method. Unlike previous MSLs typically created through stacking monolayers together with complicated method, WS₂ MSLs reported here could be obtained directly during synthesis of nanobelts driven by the mechanical instability. Emergent properties are found including superior conductivity, special superaerophobicity and superhydrophilicity, and strongly enhanced electro-catalytic activity when we apply ‘twistronics’ to the field of catalytic hydrogen production. Theoretical calculations show that such excellent catalytic performance could be attributed to a closer to thermoneutral hydrogen adsorption free energy value of twisted bilayers active sites. Our findings provide an exciting opportunity to design advanced WS₂ catalysts through moiré superlattice engineering based on mechanical flexibility.

This review systematically summarizes the recent advances in two-dimensional nanomaterials for photocatalytic reduction of CO ₂ and its related mechanisms.

Anion exchange membrane (AEM) water electrolysis employing non-precious metal electrocatalysts is a promising strategy for achieving sustainable hydrogen production. However, it still suffers from many challenges, including sluggish alkaline hydrogen evolution reaction (HER) kinetics, insufficient activity and limited lifetime of non-precious metal electrocatalysts for ampere-level-current-density alkaline HER. Here, we report an efficient alkaline HER strategy at industrial-level current density wherein a flexible WS₂ superstructure is designed to serve as the cathode catalyst for AEM water electrolysis. The superstructure features bond-free van der Waals interaction among the low Young’s modulus nanosheets to ensure excellent mechanical flexibility, as well as a stepped edge defect structure of nanosheets to realize high catalytic activity and a favorable reaction interface micro-environment. The unique flexible WS₂ superstructure can effectively withstand the impact of high-density gas-liquid exchanges and facilitate mass transfer, endowing excellent long-term durability under industrial-scale current density. An AEM electrolyser containing this catalyst at the cathode exhibits a cell voltage of 1.70 V to deliver a constant catalytic current density of 1 A cm⁻² over 1000 h with a negligible decay rate of 9.67 μV h⁻¹.

Heteroatom doping is a promising approach to enhance catalytic activity by modulating physical properties, electronic structure, and reaction pathway. Herein, we demonstrate that appropriate Ni-doping could trigger a preferential transition of the basal plane from 2H (trigonal prismatic) to 1T′ (clustered Mo) by inducing lattice distortion and S vacancy (SV) and thus dramatically facilitate its catalytic hydrogen evolution activity. It is noteworthy that the unique catalysts did possess superior catalytic performance of hydrogen evolution reaction (HER). The rate of photocatalytic hydrogen evolution could reach 20.45 mmol·g⁻¹·h⁻¹ and reduced only slightly in the long period of the photocatalytic process. First-principles calculations reveal that the distorted Ni-1T′-MoS₂ with SV could generate favorable water adsorption energy (E_ad(H₂O)) and Gibbs free energy of hydrogen adsorption (ΔG_H). This work exhibits a facile and promising pathway for synergistically regulating physical properties, electronic structure, or wettability based on the doping strategy for designing HER electrocatalysts.

Defect engineering is one of the effective strategies to optimize the physical and chemical properties of molybdenum disulfide (MoS₂) to improve catalytic hydrogen evolution reaction (HER) performance. Dislocations, as a typical defect structure, are worthy of further investigation due to the versatility and sophistication of structures and the influence of local strain effects on the catalytic performance. Herein, this study adopted a low-temperature hydrothermal synthesis strategy to introduce numerous dislocation-strained structures into the in-plane and out-of-plane of MoS₂ nanosheets. Superior HER catalytic activity of 5.85 mmol·g⁻¹·h⁻¹ under visible light was achieved based on the high-density dislocations and the corresponding strain field. This work paves a new pathway for improving the catalytic activity of MoS₂ via a dislocation-strained synergistic modulation strategy.

Efficient evolution of hydrogen through electrocatalysis holds tremendous promise for clean energy. The catalytic efficiency for hydrogen evolution reaction (HER) strongly depends on the number and activity of active sites. To this end, making vertically aligned, ultrathin, and along with rich metallic phase WS2 nanosheets is effective to maximally unearth the catalytic performance of WS2 nanosheets. Metallic 1T polymorph combined with vertically aligned ultrathin WS2 nanosheets on flat substrate is successfully prepared via one-step simple hydrothermal reaction. The nearly vertical orientation of WS2 nanosheets enables the active sites of surface edge and basal planes to be maximally exposed. Here, we report vertical 1T-WS2 nanosheets as efficient catalysts for hydrogen evolution with low overpotential of 118 mV at 10 mA cm−2 and a Tafel slope of 43 mV dec−1. In addition, the prepared WS2 nanosheets exhibit extremely high stability in acidic solution as the HER catalytic activity and show no degradation after 5000 continuous potential cycles. Our results indicate that vertical 1T-WS2 nanosheets are attractive alternative to the precious platinum benchmark catalyst and rival MoS2 materials that have recently been heavily scrutinized for hydrogen evolution. Vertical 1T-WS2 for hydrogen evolution.