Improving the electrocatalytic performance of sustainable Co/carbon materials for the oxygen evolution reaction by ultrasound and microwave assisted synthesis

The design of sustainable procedures for the preparation of cobalt/carbon-based materials as an anode for hydrogen fuel production through electrocatalytic water splitting has attracted much interest in the last few years. Herein, a novel environmentally friendly approach for the development of stable and active catalysts for the oxygen evolution reaction (OER) is reported. In detail, the methodology aimed at developing a sequence of composites having a low cobalt loading (<4%(wt)) using polyphenols extracted from green tea as metal stabilizers and activated carbon derived from pinecones as a metal-support as well as a co-active material. The approach exploited ultrasound (US), microwave (MW) and combined US/MW-assisted techniques with the purpose of enhancing the final electrocatalytic activity of these new composites, replacing conventional high-temperature approaches. The results indicated that the so-produced electrocatalytic materials followed the order of activity US > MW/US > MW > conventional heating, with the best sample requiring an overpotential of 365 mV to deliver a current density of 10 mA cm(-2) and a Tafel slope of 58 mV dec(-1).

Automated summary

The study introduces a novel environmentally friendly approach for developing stable and active catalysts for the oxygen evolution reaction, utilizing polyphenols and activated carbon derived from pinecones to prepare low cobalt loading composites. The use of ultrasound and microwave assisted techniques aimed at enhancing electrocatalytic activity, demonstrating that the best sample required an overpotential of 365mV to achieve a current density of 10mA/cm(-2) with a Tafel slope of 58mV/dec(-1).