Because of their exotic electronic properties and abundant active sites, two-dimensional (2D) materials have potential in various fields. Pursuing a general synthesis methodology of 2D materials and advancing it from the laboratory to industry is of great importance. This type of method should be low cost, rapid and highly efficient. Here, we report the high-yield synthesis of 2D metal oxides and hydroxides via a molten salts method. We obtained a high-yield of 2D ion-intercalated metal oxides and hydroxides, such as cation-intercalated manganese oxides (Na0.55Mn2O4·1.5H2O and K0.27MnO2·0.54H2O), cation-intercalated tungsten oxides (Li2WO4 and Na2W4O13), and anion-intercalated metal hydroxides (Zn5(OH)8(NO3)2·2H2O and Cu2(OH)3NO3), with a large lateral size and nanometre thickness in a short time. Using 2D Na2W4O13 as an electrode, a high performance electrochemical supercapacitor is achieved. We anticipate that our method will enable new path to the high-yield synthesis of 2D materials for applications in energy-related fields and beyond.

Transition-metal phosphides (TMPs) are considered as promising non-noble electrochemical catalysts for hydrogen evolution reaction (HER). Their highly active sites are located on certain facets, and single crystalline two-dimensional (2D) structures enable them to expose the most active facets for HER. However, the synthesis of single crystalline 2D TMPs is still a challenge owing to their intrinsically non-layered structures. Herein, we demonstrate the synthesis of various single crystalline 2D TMPs (Co2P, MoP2, Ni12P5 and WP2) by a salt-templating method. The as-synthesized 2D Co2P exhibited efficient electrocatalytic ability for HER with an overpotential of 41 mV at 10 mA cm-2 and a Tafel slope of 35 mV dec-1 in 0.5 M H2SO4 solution. We expect that the synthesis of 2D TMPs reported here will open the way to expand the family of 2D materials for electrocatalysis and beyond.

Co2P is one of the most promising non‐noble metal catalysts for hydrogen evolution reaction (HER) during water splitting, owing to its many advantages, such as earth‐abundance, high activity and good stability. The as‐synthesized Co2P is multi‐faceted while its facet‐dependent HER activity is still little known. To explore the facet‐dependent HER activity of Co2P, density functional theory (DFT) calculations are conducted for five different facets of Co2P: (001), (010), (101), (112) and (113) in this work. By comparing the surface energy and Gibbs free energy of H* (ΔGH*) of these five facets, Co2P (113) is found to possess both good surface stability and high HER activity, which could be the guidance for catalyst design and synthesis. Multiple linear regression has been adopted to quantitatively scrutinize the relationship between H−Co bond length distribution and ΔGH*, and the mean absolute error of the multiple linear regression is as small as 0.0756 eV. This analysis shows that statistical methods are effective to explore the effect of structure on the HER activity, which could be helpful in understanding the underlying HER mechanism.

Owing to high electrical conductivity and ability to reversibly host a variety of inserted ions, 2D metallic molybdenum disulfide (1T‐MoS2) has demonstrated promising energy storage performance when used as a supercapacitor electrode. However, its charge storage mechanism is still not fully understood, in particular, how the interlayer spacing of 1T‐MoS2 would affect its capacitive performance. In this work, molecular dynamics simulations of 1T‐MoS2 with interlayer spacing ranging from 0.615 to 1.615 nm have been performed to investigate the resulting charge storage capacity in ionic liquids. Simulations reveal a camel‐like capacitance‐potential relation, and MoS2 with an interlayer spacing of 1.115 nm has the highest volumetric and gravimetric capacitance of 118 F cm−3 and 42 F g−1, respectively. Although ions in MoS2 with an interlayer spacing of 1.115 nm diffuse much faster than with interlayer spacings of 1.365 and 1.615 nm, the MoS2 with larger interlayer spacing has a much faster‐charging process. Our analyses reveal that the ion number density and its charging speed, as well as ion motion paths, have significant impacts on the charging response. This work helps to understand how the interlayer spacing affects the interlayer ion structures and the capacitive performance of MoS2, which is important for revealing the charge storage mechanism and designing MoS2 supercapacitor.

A chainmail catalyst of Ni2P core encapsulated by ultrathin P-doped carbon shell anchored on graphene network demonstrates efficient and robust activity towards hydrogen evolution.