Electrocatalytic hydrogen evolution and sulfion (S²⁻) recycling are promising strategies for boosting H₂ production and removing environmental pollutants. Here, a nano-Ni-functionalized molybdenum disulfide (MoS₂) nanosheet was assembled on steel mesh (Ni-MoS₂/SM) for use in sulfide oxidation reaction-assisted, energy-saving H₂ production. Experimental and theoretical calculation results revealed that anchoring nano-Ni on high-surface-area slack MoS₂ nanosheets not only optimized catalyst adsorption of polysulfides but also played an important role in promoting hydrogen evolution reaction kinetics by absorbing OH_ad, thereby greatly enhancing the catalytic performance toward sulfide oxidation reaction and hydrogen evolution reaction. Meanwhile, the Ni/MoS₂-based hydrogen evolution reaction + sulfide oxidation reaction system achieved nearly 100% hydrogen production efficiency and only consumed 61% less power per kWh than the oxygen evolution reaction + hydrogen evolution reaction system, which suggested our proposed Ni-MoS₂ and novel hydrogen production system are promising for sustainable energy production.

Despite being pursued for a long time, hydrogen production via water splitting is still a huge challenge mainly due to a lack of durable and efficient catalysts. Molybdenum phosphide (MoP) is theoretically capable of efficient hydrogen evolution reaction (HER) catalysis, however, there is still room for further improvement in its performance. Herein, we propose a design for MoP with a P-rich outermost atomic layer for enhancing HER via complementary theoretical and experimental validation. The correlation of computational results suggests that the P-terminated surface of MoP plays a crucial role in determining its high-efficiency catalytic properties. We fabricated a P-rich outermost atomic layer of MoP nanoparticles by using N-doped porous carbon (MoP@NPCNFs) to capture more P on the surface of MoP and limit the growth of nanoparticles. Further, the as-prepared material can be directly employed as a self-supported electrocatalyst, and it exhibits remarkable electrocatalytic activity for HER in acidic media; it also reveals excellent long-term durability for up to 5, 000 cycles with negligible loss of catalytic activity.