Through a facile and effective strategy by employing lithium molten salts the controlled synthesis of 2H- and 1T-MoS monolayers with high-yield production is achieved. Both phases of MoS monolayers exhibit high stabilities. When used as a catalyst for hydrogen evolution, these phased MoS monolayers deliver respective advantages in the field of electro- and photo-catalytic hydrogen evolution.

Graphitic carbon nitride (g‐C3N4) has recently emerged as an attractive photocatalyst for solar energy conversion. However, the photocatalytic activities of g‐C3N4 remain moderate because of the insufficient solar‐light absorption and the fast electron–hole recombination. Here, defect‐modified g‐C3N4 (DCN) photocatalysts, which are easily prepared under mild conditions and show much extended light absorption with band gaps decreased from 2.75 to 2.00 eV, are reported. More importantly, cyano terminal CN groups, acting as electron acceptors, are introduced into the DCN sheet edge, which endows the DCN with both n‐ and p‐type conductivities, consequently giving rise to the generation of p–n homojunctions. This homojunction structure is demonstrated to be highly efficient in charge transfer and separation, and results in a fivefold enhanced photocatalytic H2 evolution activity. The findings deepen the understanding on the defect‐related issues of g‐C3N4‐based materials. Additionally, the ability to build homojunction structures by the defect‐induced self‐functionalization presents a promising strategy to realize precise band engineering of g‐C3N4 and related polymer semiconductors for more efficient solar energy conversion applications.

An efficient nitrogen fixation reaction is highly desirable for obtaining the essential chemicals and energy carriers but remains a challenge due to the strong nonpolar bonding and considerable activation barrier of the NN triple bond (bond energy 940.95 kJ mol−1). Using an appropriate nanostructured catalyst that strongly interacts with nitrogen could promote adsorption and activation, lowering the energy barrier of nitrogen fixation and thus resulting in a relatively mild reaction. In this article, the review of the recent progress in nanostructured catalytic materials for nitrogen fixation is presented, including a comprehensive introduction and discussion on the pathway and mechanism of nitrogen fixation reaction, the recent achievements of a variety of nanostructured catalysts, and the kinds of catalytic nitrogen fixation reactions they are used in. In addition, the challenges faced by the reaction, strategies of catalyst design, and outlooks for further improving the performance of nitrogen fixation are also highlighted.