A multifunctional Mo–N/Fe–N interfaced MoS2/FeNC electrocatalyst for energy conversion applications

Heteroatomdopingandphaseengineeringhavebecomecaptivatingstrategiestoboostthemultifunctional
catalytic activity of an electrocatalyst for energy conversion. In this study, for the first time, we synthesized
a polymer–ironcomplex(Fe-polydiaminonaphthalene) andpyrolyzed it to produceFe andN dopedcarbon
nanospheres, and then vertically aligned MoS2 nanosheets were anchored to the doped carbon
nanospheres (MoS2/FeNC). During pyrolysis, Mo–N was formed in the MoS2/FeNC matrix and served as
an active site enabling robust trifunctional catalytic activity towards the ORR, the HER, and H2O2
reduction. MoS2/FeNC exhibits excellent performance for the ORR with onset and half-wave potentials
(E1/2) of 0.988 V and 0.866 V (vs. RHE), respectively, and a Tafel slope of 58 mV dec−1, better than those
of benchmark Pt/C (E1/2 = 0.861 V and 60 mV dec−1), with excellent methanol tolerance and stability in
0.1 M KOH. The catalytic activity towards the HER is also remarkable, with an overpotential of 128 mV at
10 mA cm−2 in alkaline media. Additionally, the electrocatalytic behavior towards H2O2 reduction exhibits
enhanced analytical performance for detecting H2O2 from A549 cells with a low detection limit of 200
nM (S/N = 3). The energy level and charge distribution calculation for the proposed catalysts suggested
that forming MoS2 nanosheets on the FeNC surface facilitated multifunctional catalytic activity for
sustainable applications.