Millisecond-timescale electrodeposition of platinum atom-doped molybdenum oxide as an efficient electrocatalyst for hydrogen evolution reaction

We present a straightforward method for one-pot electrodeposition of platinum atoms-doped molybdenum oxide (Pt·MoO3−x) films and show their superior electrocatalytic activity in the hydrogen evolution reaction (HER). A ∼15-nm-thick Pt·MoO3−x film was prepared by one-pot electrodeposition at −0.8 V for 1 ms. Due to considerably different solute concentrations, the content of Pt atoms in the electrode-posited composite electrocatalyst is low. No Pt crystals or islands were observed on the flat Pt·MoO3−x films, indicating that Pt atoms were homogeneously dispersed within the MoO3−x thin film. The catalytic performance and physicochemical features of Pt·MoO3−x as a HER electrocatalyst were characterized. The results showed that our Pt·MoO3−x film exhibits 23- and 11-times higher current density than Pt and MoO3−x electrodeposited individually under the same conditions, respectively. It was found that the dramatic enhancement in the HER performance was principally due to the abundant oxygen defects. The use of the developed one-pot electrodeposition and doping method can potentially be extended to various catalytically active metal oxides or hydroxides for enhanced performance in various energy storage and conversion applications.