During the last decade, immense interest has been given to overcoming water pollution and energy storage issues. Conventional water treatment technologies and hydrogen production (replacement of fossil fuels) exhibit certain limitations. Therefore, the present research focuses on the application of novel molybdenum-iron (MoFe) nanosheets in the removal of various water pollutants through membrane filtration technology. Furthermore, the used nanocomposite membranes during the water treatment were recycled for hydrogen production through hydrogen evolution reaction (HER). Membrane studies depicted excellent rejection of water contaminants through MoFe nanocomposite membrane, i.e., 94%–99% removal for dyes with flux rates up to 288 L/m2.h. Whereas 63.4%, 81.3%, and 98.7% removal were achieved for total dissolved solids, total organic carbon, and turbidity, respectively, and toxic metals exhibited 100% removal with a maximum flux rate of 260 L/m2.h. Moreover, a multi-cycle filtration run for the optimized membrane revealed excellent stability performance. HER studies exhibited the remarkable stability of MoFe-based catalysts during electrochemical activity, and their electrochemical kinetics was found to be quite comparable to platinum (Pt) catalysts. All findings supported the extraordinary potential of MoFe nanosheets in water treatment through membrane filtration and their further application as a sustainable option for hydrogen production during the HER process. Hence, the effectiveness of MoFe nanosheets signifies a promising solution for large-scale applications in both water and energy fields, which can not only enhance water purification and provide an affordable alternative to expensive catalysts used in HER but also overcome the limitations of traditional water treatment techniques and hydrogen production.