Ru doped CoP nanosheets for efficient hydrogen evolution in microbial electrolysis cells

Abstract

Microbial electrolysis cells (MECs) are an emerging hydrogen production technology that can potentially purify wastewater at the anode and simultaneously produce hydrogen at the cathode. Development of low-cost and high-efficiency catalysts toward the cathodic hydrogen evolution reaction (HER) is crucial to realize the practical application of MECs for hydrogen production. In this work, ruthenium-doped cobalt phosphide nanosheets (Ru/CoP NSs) are prepared for the HER in alkaline solution (1 M KOH) and neutral phosphate buffered solution (1 M PBS) with impressive over potentials of 38 mV and 148 mV at 10 mA cm⁻², respectively. The MECs are set up by coupling a microbial anode with a Ru/CoP NS cathode which enables an electrolytic current density of ∼16.74 A m⁻² at an applied voltage of 0.8 V, with a hydrogen production rate (Q_H2) is 0.1434 ± 0.0082 m³ m⁻² d⁻¹. Notably, the MECs with Ru/CoP NS catalysts (Ru/CoP NSs-MEC) outperform the MECs with the commercial Pt/C catalysts (Pt/C-MECs), indicating the potential of Ru/CoP NSs to replace Pt for practical H₂ production in MEC applications.