Tungsten-based porous thin-films for electrocatalytic hydrogen generation

Developing inexpensive and efficient electrocatalysts without using precious metals for the hydrogen evolution reaction (HER) is essential for the realization of economical clean energy production. Here we demonstrate a facile approach to access interconnected three-dimensional (3-D) porous tungsten-based (WS2 and WC) thin-films without using any templates. Benefiting from the 3-D open frameworks of these highly porous thin-films, there are enormous amounts of exposed active sites and efficient mass transport in favor of the HER. Both electrodes exhibit excellent catalytic activity towards HER with onset overpotentials of similar to 100 mV for WS2 and similar to 120 mV for WC, and similar Tafel slopes of similar to 67 mV per decade. The long-term operation of these thin-film electrodes is confirmed by their electrochemical stability test. With the low loading mass (similar to 80 and similar to 160 mg cm(-2) for WS2 and WC, respectively), these porous thin-films are among the best tungsten-based HER electrocatalysts.