Thermally Labile Organic-Soluble Heterometal Diorganophosphate-Derived Efficient Electrocatalysts for the Oxygen Evolution Reaction

Heterometal phosphates are burgeoning electrocatalysts and cathode materials in energy storage and conversion devices. In this work, we demonstrate a novel and clean synthetic route for substoichiometric lithium-deficient metastable Cmcm -Li 0.65(7) Co 1.16(2) PO 4 ( Li-Co-P-HEX ) and metaphosphate P 2 1 2 1 2 1 -LiCo(PO 3 ) 3 ( Li-Co-P-BT ), starting from the same starting material [LiCo(dtbp) 3 ] (dtbp = di- tert -butyl phosphate) through a thermolytic single-source precursor approach. The heterometal organophosphate [LiCo(dtbp) 3 ] decomposed into different phases of inorganic heterometal phosphates by employing a solution and solid-state thermal treatment. The solution-processed Li-deficient orthophosphate exhibits superior oxygen evolution reaction activity, delivering a current density of 10 mA cm –2 at an overpotential of 294 mV, outperforming other reported lithium–cobalt phosphates for water oxidation. The enhanced performance of the Cmcm -Li 0.65(7) Co 1.16(2) PO 4 as an electrocatalyst elucidates the synergistic effect generated by the structure, composition, and morphology.