Amorphous/2H-MoS2 nanoflowers with P doping and S vacancies to achieve efficient pH-universal hydrogen evolution at high current density

Molybdenum disulfide (MoS2) has become a competitive candidate for efficient and economical hydrogen evolution reaction (HER). Compared with 1T-MoS2, 2H-MoS2 possesses exceptional thermodynamic stability but still suffers from low active site density, poor conductivity, and weak hydrogen bonding in the wide pH range. Herein, 2H-MoS2 nanoflowers with phosphorus doping, sulfur vacancies and crystalline-amorphous heterojunction were synthesized via phosphorus-assisted rapid calcination method. Benefiting from the cooperative interaction of multiple strategies, the prepared 2H-MoS2 nanoflowers firstly achieve efficient pH-universal HER at high current densities. Experimental results show that in alkaline, acidic, and neutral media, MoS2-P2 requires only 332, 302, and 417 mV to drive the current density of 500 mA cm−2 and obtains 932, 1100, and 472 mA cm−2 at the potential of −0.4 V vs. RHE, respectively. Moreover, MoS2-P2 shows excellent stability of low and high current density in the full pH range.