Bifunctional catalysts are prominent to attain high capacity, maximum energy efficiency and long cycle-life for aqueous rechargeable Na-air batteries. In this work, we report the synthesis of bi-functional noble metal free, Co3(PO4)2 nanostructures by facile precipitation technique and evaluated its electrocatalytic activity. Co3(PO4)2 nanostructure was investigated as a potential electrocatalyst for rechargeable aqueous Na-air battery for the first time. The synthesized Co3(PO4)2 grain-like nanostructures showed better oxygen evolution activity compared to Pt/C catalyst. The fabricated Na-air battery with the Co3(PO4)2 catalyst as air-cathode delivered low overpotential and its round trip energy efficiency reached up to 83%. The Na-air battery exhibited stable cycle performance up to 50 cycles.