Vertical 1T‐TaS2 Synthesis on Nanoporous Gold for High‐Performance Electrocatalytic Applications

2D metallic TaS₂ is acting as an ideal platform for exploring fundamental physical issues (superconductivity, charge‐density wave, etc.) and for engineering novel applications in energy‐related fields. The batch synthesis of high‐quality TaS₂ nanosheets with a specific phase is crucial for such issues. Herein, the successful synthesis of novel vertically oriented 1T‐TaS₂ nanosheets on nanoporous gold substrates is reported, via a facile chemical vapor deposition route. By virtue of the abundant edge sites and excellent electrical transport property, such vertical 1T‐TaS₂ is employed as high‐efficiency electrocatalysts in the hydrogen evolution reaction, featured with rather low Tafel slopes ≈67–82 mV dec^?1 and an ultrahigh exchange current density ≈67.61 µA cm^?2. The influence of phase states of 1T‐ and 2H‐TaS₂ on the catalytic activity is also discussed with the combination of density functional theory calculations. This work hereby provides fundamental insights into the controllable syntheses and electrocatalytic applications of vertical 1T‐TaS₂ nanosheets achieved through the substrate engineering.     

A Joint Experimental and Computational Search for Authentic Nano‐electrocatalytic Effects: Electrooxidation of Nitrite and L‐Ascorbate on Gold Nanoparticle‐Modified Glassy Carbon Electrodes

The investigation of electrocatalytic nanoeffects is tackled via joint electrochemical measurements and computational simulations. The cyclic voltammetry of electrodes modified with metal nanoparticles is modeled considering the kinetics of the electrochemical process on the bulk materials of the different regions of the electrode, that is, the substrate (glassy carbon) and the nanoparticles (gold). Comparison of experimental and theoretical results enables the detection of changes in the electrode kinetics at the nanoscale due to structural and/or electronic effects. This approach is applied to the experimental assessment of electrocatalytic effects by gold nanoparticles (Au NPs) in the electrooxidation of nitrite and L‐ascorbate. Glassy carbon electrode is modified with Au NPs via seed‐mediated growth method. Divergence between the kinetics of these processes on gold macroelectrodes and gold nanoparticles is examined. Whereas claimed catalytic effects are not observed in the electrooxidation of nitrite, electrocatalytic nanoeffects are verified in the case of L‐ascorbate. This is probably due to that the electron transfer process follows an adsorptive mechanism. The combination of simulation with experiments is commended as a general strategy of authentification, or not, of nanoelectrocatalytic effects.