Biphasic Mo-based catalysts with abundant pores and rich heterostructures for high-efficient production of hydrogen in both alkaline and acidic media

Abstract

Electrolysis of water to produce H2 demands high-efficient catalysts. Herein, biphasic γ-MoC/MoS2/C electrocatalyst with heterostructures was prepared using methyl orange as the low-cost C and S resource. The γ-MoC/MoS2/C presented convoluted nanosheets with abundant pores and rich heterostructures, which owed it excellent catalytic performance in both of 1 M KOH and 0.5 M H2SO4 solutions. The overpotentials required to reach 10 mA·cm−2 were 58 mV and 81 mV, respectively, under alkaline and acidic conditions. γ-MoC/MoS2/C also exhibited satisfactory long-term stability, that negligible decrease of the LSV curves was observed after 3000 CV cycles. The current density was maintained at approximately 95 % and 91 % in 1 M KOH and 0.5 M H2SO4 solutions, respectively, over 36 h. DFT results showed that the ΔGHads* value of γ-MoC/MoS2/C is −0.12 eV, approaching to zero, which is conducive to the adsorption and desorption of Hads* and thus promotes the hydrogen evolution reactions (HER). The synthesis of γ-MoC/MoS2/C was quite facile and flexible, which avoid stepwise carbonization and sulfuration. It is expected to provide a fresh reference for the synthesis of high-efficient, low-cost and susceptible Mo-based catalysts.