Co3O4/stainless steel catalyst with synergistic effect of oxygen vacancies and phosphorus doping for overall water splitting

The electrolysis of water into hydrogen and oxygen provides an effective means of storing electrical energy indirectly. The current challenge is to design an optimal catalyst that exhibits low overpotentials, long-term stability, universal availability, and only uses inexpensive materials. Herein, a Co3O4 nanoflower/stainless steel (P-Ov-Co3O4/SS) catalyst with both oxygen vacancies (Ovs) and phosphorus doping was perfectly prepared via a simple three-step method. The Ovs promoted charge transfer and accelerated the electrocatalysis, while P finely tuned the surface charge state. This resulted in numerous active sites for catalysis, and the synergistic effect of phosphorus doping and oxygen vacancies was finely demonstrated. The resultant electrocatalyst exhibited low hydrogen evolution overpotentials of 118 mV (- 10 mA center dot cm(-2)) and 242 (- 200 mA center dot cm(-2)), as well as oxygen evolution overpotentials of 327 mV (100 mA center dot cm(-2)) and 370 mV (200 mA center dot cm(-2)), owing to the excellent synergistic effect of the Ovs and low-temperature phosphating. Moreover, P-Ov-Co3O4/SS//P-Ov-Co3O4/SS exhibited a low water splitting voltage of 1.681 V at 20 mA center dot cm(-2). These findings will enable the synthesis of novel high-performance electrocatalysts for overall water splitting.

Automated summary

The article discusses the design and synthesis of an optimal catalyst for water electrolysis to store electrical energy. The catalyst, Co3O4 nanoflower/stainless steel (P-Ov-Co3O4/SS), combines oxygen vacancies and phosphorus doping, resulting in a synergistic effect and numerous active sites for catalysis. The electrocatalyst exhibits low overpotentials for both hydrogen and oxygen evolution, making it a promising candidate for overall water splitting.