Morphology‐controlled growth of large‐area PtSe ₂ films for enhanced hydrogen evolution reaction

Transition metal dichalcogenides (TMDs) have emerged as a promising electrocatalyst for hydrogen evolution reaction (HER) due to its excellent conductivity and abundant electrocatalytic active sites of its edges. TMDs nanowall can expose abundant of edges so that they tend to show better catalytic performance for hydrogen evolution reaction. Herein, PtSe 2 nanowall films with morphology controlled at centimeters level are synthesized by selenizing Pt film. The dynamic and thermodynamics of selenation reaction are investigated. The nanowall structure can be obtained by controlling the growth temperature, and the thickness of nanowall can be tuned by the original thickness of Pt film. The Pt atoms can be rearranged into ordered distribution at 550 °C and can be induced to well‐ordered PtSe 2 nanowalls finally. The well‐ordered PtSe 2 nanowall films show excellent HER performance, with an overpotential of 0.3 V at −10 mA·cm −2 and a Tafel slope of ∼52 mV·dec −1 . This work demonstrates the great potential of activated 2D PtSe 2 as an ultrathin film catalyst for the HER, which is valuable to provide instruction and afford experience for further application at industrial level.