A similar enhancement in HER catalysis has been observed in medium-entropy oxides. For instance, a medium-entropy CoNiCu oxide cocatalyst exhibited a maximum hydrogen production rate of 1177.52 μmol•g -1 •h -1 under visible light, which is approximately 291 times higher than that of pure g-C3N4 . This enhancement is attributed to reduced ΔGH* and improved photoinduced charge separation and transfer .In conclusion, both high-entropy and medium-entropy materials offer unique advantages for HER catalysis, including enhanced electronic effects, optimized active sites, and improved charge transfer properties. These findings suggest that entropy engineering is a promising approach for developing highperformance HER catalysts.