Greenly Synthesized CoPBA@PANI as a Proficient Electrocatalyst for Oxygen Evolution Reaction and Its Green...

Water electrolysis is a key factor to generate mobile and sustainable energy sources for H₂ production. Cobalt-based Prussian Blue analogues encompassed with polymer support electrocatalysts CoPBA_X@PANI (CoPBA@PANI-100, CoPBA@PANI-200, and CoPBA@PANI-300) have been synthesized and characterized. The well-designed CoPBA@PANI-200/GC shows a low overpotential (η₁₀) of 301 mV with a small Tafel slope (56 mV dec^-1), comapred to that of IrO₂ (348 mV ; 98 mV dec^-1) for OER. The conductivity with stability of CoPBA_X@PANI have been increased due to the synergistic effect of CoPBA with PANI. PANI provides additional active sites and shows strong binding with Co ions, and the even distribution of CoPBA overcomes the sluggish kinetics. The turnover frequency (TOF) of CoPBA@PANI-200/GC (0.0212, s^-1) was ∼15 times higher than IrO₂ (0.0014 s^-1) at 1.60 V. Furthermore, CoPBA@PANI-200/NF delivers low overpotential of 274 mV@10 mA cm^-2 and exhibits a durability of >250 h with a potential loss of 4.2%. Benefiting from strong electronic interaction between polymer support and evenly distributed CoPBA, CoPBAx@PANI shows higher electrochemical active surface area (ECSA) of 53.08 mF cm^-2. The solar-based water electrolysis confirmed the practical use of CoPBA@PANI-200/NF (1.57 V) for eco-benign industrial H₂ production. The CoPBA@PANI-200 shows exceptional OER performances as well as favorable kinetics to resolve the sluggish water oxidation. Hence, the cost-effective CoPBA@PANI performances opens a prospective way to boost the efficiency of other cobalt-derived catalysts in renewable energy devices.