3. Conclusions
In this work, we successfully prepared self-standing 1T/2H mixed phases
of MoSe2 on a carbon paper using a direct growth
approach via hydrothermal synthesis method, where post in-situ Pt
decoration was carried out by electrodeposition method. The
electrocatalyst (Pt decorated1T/2H mixed phase of MoSe2)
prepared by this simple two step approach exhibit high HER activity (133
mV at 10 mA/cm2) under the acidic medium (0.5 M
H2SO4). The direct growth of 1T/2H mixed
phase MoSe2 on a carbon paper contributes to the lower
Rct with reduction in the overpotential by 10 mV at a
current density of 10 mA/cm2 compared to the
electrocatalyst prepared by conventional (electrocatalyst + binder)
approach. Moreover, low concentration (0.15 wt%) decoration of Pt
contributes to significant enhancement in the HER activity with further
reduction in Rct compared to the pristine 1T/2H
MoSe2 electrocatalyst without the Pt deposition. Such
results are well supported by the DFT calculation and provides insight
on enhanced HER activity at the phase boundary region in
MoSe2 compared to the 1T or 2H alone regions due to the
electron accumulation at the heterointerface, while Pt clusters
interacts with Se site in MoSe2 while perturbing the
electronic states of MoSe2, which further improves the
HER activity and confirmed through ΔGH and
Ed analysis, highlighting a origin of phase dependent
HER performances in MoSe2 based electrocatalyst in the
presence of a dopant, which will pave a way for developing advanced
metal dichalcogenide 2D material based electrocatalyst in future.