Twinned Tungsten Carbonitride Nanocrystals Boost Hydrogen Evolution Activity and Stability

Abstract

Synergistic integration of two active metal‐based compounds can lead to much higher electrocatalytic activity than either of the two individually, due to the interfacial effects. Herein, a proof‐of‐concept strategy is creatively developed for the successful fabrication of twinned tungsten carbonitride (WCN) nanocrystals, where W2C and WN are chemically bonded at the molecule level. High‐angle annular dark‐field scanning transmission electron microscopy (HAADF‐STEM) and X‐ray absorption fine structure (XAFS) spectroscopy analyses demonstrate that the intergrowth of W2C and WN in the WCN nanocrystals produces abundant N–W–C interfaces, leading to a significant enhancement in catalytic activity and stability for hydrogen evolution reaction (HER). Indeed, it shows 14.2 times higher and 140 mV lower in the respective turn‐over frequency (TOF) and overpotential at 10 mA cm−2 compared to W2C alone. To complement the experimental observation, the theoretical calculations demonstrate that the WCN endows more favorable hydrogen evolution reaction than the single W2C or WN crystals due to abundant interfaces, beneficial electronic states, lower work function, and more active W sites at the N–W–C interfaces.

Plasmonic Enhanced Reactive Oxygen Species Activation on Low‐Work‐Function Tungsten Nitride for Direct Near‐Infrared Driven Photocatalysis

“…[6a,c] Therefore, the lower work function of WN-cub foreseeing its superiority potential on electron donation and ROS activation. [15] Finally, the dielectric function and optical absorption coefficient are calculated (Figure 1d,e). The real part of the dielectric function presents a negative value window between 600 and 2100 nm for WN-cub, and the image part dielectric function of WN-cub shows a peak at 1500 nm, revealing the significant NIR-plasmonic behavior the metallic WN.…”

Metal-organic Framework-driven Porous Cobalt Disulfide Nanoparticles Fabricated by Gaseous Sulfurization as Bifunctional Electrocatalysts for Overall Water Splitting

“…Transition metal oxides 13,14 , hydroxides 15,16 , carbide 17 , nitride 18 , phosphide 19 , and sulfides 20–22 have been studied as OER electrocatalysts under alkaline conditions, and transition metal sulfides 20–22 , phosphides 6,7 , carbonitride 23 , and selenides 24 have been studied as HER electrocatalysts under acidic conditions. In regard to OER and HER performance, the effects of activation and optimization of electrocatalysts have recently been reported 17,18,23 . Furthermore, with a growing demand for simplicity and cost effectiveness, the need for bifunctional electrocatalysts, which operate in the same electrolyzer, is rapidly increasing 21,25,26 .…”

Selective Growth of High‐Density Anatase {101} Twin Boundaries on High‐Energy {001} Facets

“…Crystal TB are generally formed during crystal growth and/or induced through deformation/glide or during phase transformation. To date, different synthetic approaches, such as hydro/solvothermal, [2b,5] catalyzed vapor–liquid–solid (VLS), [ 6 ] catalyst‐free selective‐area metal‐organic vapor‐phase epitaxy (MOVPE), [ 7 ] molecular beam epitaxy (MBE), [ 8 ] pulse laser ablation, [ 9 ] have been reported for the fabrication of twinned crystal structures of noble metals, [ 10 ] metal oxides, [9a] chalcogenides, [8b,11] phosphides, [ 12 ] carbonitride, [ 13 ] and some III–V element compounds. [ 14 ] The reported twin crystal structures include particles, [2b,5] nanowires, [ 14,15 ] spheres, [ 9 ] nanosheets, [8b] and films [1a] .…”