A trifunctional Co0.85Se/NC collaborated electrocatalyst enables a self-powered energy system for uninterrupted H2 production

Abstract

Extensive progress has been made in electrocatalytic water splitting technologies powered by direct electricity or solar cells. However, obtaining electric energy from the power grid or sunlight with intermittent nature will inevitably lead to external energy loss and limit the operation of water splitting. Therefore, a novel energy system that uses only clean solar energy to produce H₂ while overcoming the restrictions of intermittent sunlight is highly desirable. In this work, trifunctional Co_0.85Se/NC catalysts have been synthesized, exhibiting promising OER, ORR and HER performance. On the basis of Co_0.85Se/NC catalysts, a self-powered energy system was constructed through connecting a silicon solar cell, zinc–air batteries and a water splitting device to achieve significant H₂ generation. The energy source of the whole system is solar energy. A zinc–air battery is charged by a solar cell for power storage during the day, and discharges consistently to provide a steady power supply for water splitting at night. Simultaneously, water splitting can also be driven directly by solar energy, which ensures uninterrupted power supply for efficient H₂ generation, eliminating sunlight intermittency. The conversion efficiency of the solar-to-water splitting device and solar-to-H₂ is 5.36% and 4.34%, respectively. This work presents a novel and intriguing approach to green renewable energy generation, as well as energy conversion and storage.