MoS2/Mo2TiC2Tx supported Pd nanoparticles as an efficient electrocatalyst for hydrogen evolution reaction in both acidic and alkaline media

Development of electrocatalytic hydrogen production technology is the key to solving environmental and energy problems. Two-dimensional material Mo 2 TiC 2 T x (T x = –OH, –F) has shown great potential in electrocatalytic hydrogen evolution because of its excellent conductivity and hydrophilicity. However, due to the lack of sufficient active sites of Mo 2 TiC 2 T x itself, its practical applications in electrocatalytic hydrogen evolution are limited. In this work, a highly-efficient hydrogen evolution electrocatalyst, namely Pd@MoS 2 /Mo 2 TiC 2 T x , is prepared through a simple pyrolysis method. In such a composite, the MoS 2 nanoflowers hybridized with the ammonia-treated Mo 2 TiC 2 T x (MoS 2 /Mo 2 TiC 2 T x ) are used as a substrate for loading a small number of Pd nanoparticles (4.27 at.%). Notably, the introduction of Pd nanoparticles into MoS 2 /Mo 2 TiC 2 T x provides abundant active sites for the hydrogen evolution reaction, improves the conductivity of the electrocatalyst, speeds up the adsorption and desorption of hydrogen, and induces a synergistic effect with the MoS 2 . As a result, the Pd@MoS 2 /Mo 2 TiC 2 T x catalyst exhibits excellent electrocatalytic performance and remarkable stability in both acidic and alkaline media. In a 0.5 mol/L H 2 SO 4 electrolyte, the overpotential of Pd@MoS 2 /Mo 2 TiC 2 T x was 92 mV with a Tafel slope of 60 mV/dec at a current density of 10 mA/cm 2 . Meanwhile, the catalyst displayed an overpotential of 100 mV associated with a Tafel slope of 80 mV/dec at the current density of 10 mA/cm 2 in a 1 mol/L KOH electrolyte. This work shows the great potential of using Mo 2 TiC 2 T x -based material in the field of electrocatalysis. • Pd@MoS 2 /Mo 2 TiC 2 T x electrocatalyst for HER is explored. • Atomic ratio of Pd nanoparticles in Pd@MoS 2 /Mo 2 TiC 2 T x is only 4.27 at.%. • Pd@MoS 2 /Mo 2 TiC 2 T x shows excellent HER performance in both acidic and alkaline media. • Pd@MoS 2 /Mo 2 TiC 2 T x has excellent HER catalytic stability under long-term testing.