Vertical 1T-TaS Synthesis on Nanoporous Gold for High-Performance Electrocatalytic Applications.

2D metallic TaS 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 TaS nanosheets with a specific phase is crucial for such issues. Herein, the successful synthesis of novel vertically oriented 1T-TaS 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-TaS is employed as high-efficiency electrocatalysts in the hydrogen evolution reaction, featured with rather low Tafel slopes ≈67-82 mV dec and an ultrahigh exchange current density ≈67.61 µA cm . The influence of phase states of 1T- and 2H-TaS 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-TaS nanosheets achieved through the substrate engineering.