High-entropy metal sulfide nanoparticles with optimized metal composition as highly efficient electrocatalysts for N2 reduction to NH3

• (FeCoNiMoCr)Sx high-entropy sulfide achieves an NH3 yield rate of 47.97 μg/(h·mgcat) at −0.7 V vs RHE and a Faradaic efficiency of 26.1% at −0.4 V vs RHE, outperforming other metal compositions. • The two-step solvothermal synthesis enables the formation of high-entropy sulfides with multiple metal components, which exhibit enhanced charge transport and abundant active sites for NRR. • The synergistic effects among Fe, Co, Ni, Mo, and Cr in the high-entropy structure suppress the competing hydrogen evolution reaction, improving NRR selectivity. • This work provides a rational design strategy for high-entropy sulfide electrocatalysts, offering a promising pathway for sustainable ammonia synthesis under ambient conditions.