Interfacial Engineering of Cobalt Titanate With Phosphorus Doped Carbon Nanosheets for Optimal Oxygen Redox Catalysis

The oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are the bottlenecks that govern the performance of contemporary electrochemical energy conversion and storage devices. The synergistic strategy of coupling cobalt titanate (CoTiO₃) composites with phosphorus-doped carbon substrates is explored to enhance the active sites, conductivity, and electrocatalytic activity of CoTiO₃. However, the typical carbon substrates like reduced graphene oxide (rGO) and graphitic carbon nitride (g-C₃N₄) are limited by tedious synthesis methods using toxic reagents and low active surface area, respectively. Alternatively, defect-rich P-doped carbon nanosheets (CP) with enhanced active surface area and conductivity using eco-friendly citric acid is proposed as promising support material for boosting the OER/ORR performance of CoTiO₃. As such, the composite CoTiO₃/CP exhibits promising bifunctional performance in OER/ORR with a bifunctional index (ΔE) value of 0.8 V, due to the interfacial engineering of the hybrid material with the synergistic effects of CoTiO₃ and CP layers.