Vertically aligned NiFeP@Ni nanotubes for efficient electrochemical production of green hydrogen and sulfur: Circular economy meets sustainable energy

Abstract

A massive quantity of hydrogen sulfide (H₂S) is produced in the industrial world as an unwanted waste due to the processing of fossil fuels, such as natural gas, petroleum, and coal gasification. This necessitates a more environmentally friendly method for its conversion into more valuable products, such as hydrogen (H₂) and sulfur (S). Herein, the scalable electrochemical alloying-dealloying approach is used to prepare the self-generated vertically aligned porous Ni nanotube on Ni foam. Benefiting from the excellent catalytic activity of phosphorus-based materials, NiFeP nanocomposite is fabricated using the electrochemical deposition technique. The fabricated composite illustrates the vertically aligned nanosheets on the Ni nanotubes, which efficiently increases the active sites of the electrode. The fabricated electrodes demonstrate excellent anodic sulfur oxidation reaction (SOR) and cathodic hydrogen evolution reaction (HER). The sulfur oxidation reaction was initiated at 0.093 V vs RHE, which is 1.13 V less than the thermodynamic potential of the oxygen evolution reaction (1.23 V). The stability of NiFeP@Ni@NF electrode for simultaneous HER and SOR in bi-functional electrolyser was measured for time interval of 25 h at 0.7 V cell voltage. This work provides a route for low-cost, large-scale hydrogen synthesis from industrial by-products by presenting a novel approach for effectively manufacturing hydrogen while recycling hazardous sulfide waste.