In-situ construction of ultrathin MoP-MoS2 heterostructure on N, P and S co-doped hollow carbon spheres as nanoreactor for efficient hydrogen evolution

• N-rich polypyrrole-co-aniline hollow nanospheres serve as carbon precursors. • N, P and S co-doped optimize the electronic structure of carbonaceous catalyst. • Ultrathin MoP-MoS 2 heterojunction is in-situ constructed on N, P and S co-doped HCSs. • The strong interaction among MoP, MoS 2 and HCSs helps to charge and mass transfer. • The as designed catalyst displayed remarkable HER activity and long-term durability. Rational design hierarchical nano-heterojunction electrocatalysts with high activity and durability for hydrogen evolution reaction (HER) are attractive for sustainable energy conversion. Here, one-step and space-confine pyrolysis strategy is demonstrated to in-situ construct ultrathin MoP-MoS 2 heterostructure on N, P and S co-doped hollow carbon spheres (MoP-MoS 2 /HCSs) that present remarkable HER performance. The intimate contact among MoP outer-layer, MoS 2 intermediate layer and N, P and S co-doped HCSs inner-layer facilitates the formation of triple-shelled heterogeneous nanoreactor. Benefiting from abundant active sites, high specific surface area, heteroatomic doping, intimate catalyst-substrate contact and ultrathin active heterostructure, the resulting MoP-MoS 2 /HCSs not only displays significant electrocatalytic activity with low overpotentials (71 mV and 125 mV in 1.0 M KOH and 0.5 M H 2 SO 4 , respectively) at current density of 10 mA cm −2 , but exhibits outstanding stability toward HER process. This study offers a promising approach to design hierarchical nano-heterojunction with remarkable electrochemical properties for green energy development.