The advancement of spotless hydrogen energy generation is being accelerated by the advancement in nonprecious electrocatalysts for effective hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and overall water splitting. In this review, the main focus is given to the most significant innovations in the surface topography, morphological shape, size distribution, and electrocatalytic functionality of highly engineered molybdenum nitride catalysts, equal to or even better than state-of-the-art electrocatalyst for HER and OER. Different morphological or interfacial engineering techniques, such as in situ electrospinning, topochemical methods, and classic chemical methods for synthesizing nonprecious molybdenum nitride electrocatalysts, are extensively covered. Molybdenum nitrides are discovered the excellent electrocatalyst, and the factors that can improve its electrocatalytic properties, such as morphological tuning, controlled geometrical composition, pH effect, hybrid and electronic structures, the effect of temperature, and effects of active sites, are comprehensively discussed.