Vertically stacking two-dimensional (2D) materials with small azimuthal deviation or lattice mismatch generate distinctive global structural periodicity and symmetry, revealed as the moiré superlattices (MSLs). Manipulating the interlayer twist angle enables the modification of the electronic structure of 2D materials to explore the advanced applications. Although extraordinary progress has been achieved in the unique structure and emergent properties of MSLs, the investigation of the catalytic applications of MSLs materials is still in its infancy. It is therefore very urgent to summarize the advanced development of MSLs in the field of catalysis. In this review, we firstly summarize the advanced fabrication and high-resolution characterization techniques of the MSLs materials, as well as their novel properties related to catalysis represented by electrocatalytic hydrogen evolution reaction (HER). Then, all the MSLs materials such as MoS₂, WS₂, and Ru serving as electrocatalysts for HER are further reviewed in detail. Finally, we outline the current challenges as well as the experimental and theoretical strategies to advance the development of function-oriented MSLs materials for catalysis. This review aims to provide profound insight into the wide applications of this novel material platform in catalytic field.

As a clean, efficient, and sustainable energy, hydrogen is expected to replace traditional fossil energy. A series of studies focusing on morphology regulation, surface modification, and structural reconstruction have been devoted to improving the intrinsic catalytic activity of non-noble metal catalysts. However, complex system structure design and the mutual interference of various chemical components would hinder the further improvement of hydrogen evolution performance. In recent years, external field assisted hydrogen evolution reaction (HER) has become a new research hotspot. Herein, we systematically summarize the promoting effects of various external fields on catalytic hydrogen production from the aspects of system design and catalytic mechanism, including electric field, thermal field, optical field, magnetic field, and acoustic field. Ultimately, we discuss the key challenges facing this external field regulation strategy and put forward the prospect of future research topics. We sincerely expect that this review could not only provide a new insight into the basic mechanism of external-assisted catalysis, but also promote further research on improving HER performance from a more diverse and comprehensive perspective.

Electrochemical gas evolution reactions are common but essential in many electrochemical processes including water electrolysis. During these processes, gas bubbles are constantly nucleating on reaction interfaces in electrolyte and consequently exert an impact on catalysts and the performance. In the past few decades, extensive studies have been conducted to characterize bubbles with emerging advanced technologies, manage behaviors of bubbles, and apply bubbles to various domains. In this review, we summarize representative discoveries as well as recent advancements in electrochemical gas evolution reactions from the perspective of gas bubbles. Finally, we end up this review with a profound outlook on future research topics from the combination of experiments and theoretical techniques, non-negligible bubble effects, gravity-free situation, and reactions under practical industrial conditions.