V-doped transition metal selenides derived from NiFe Prussian blue analogues for efficient oxygen evolution reaction and urea oxidation reaction

Hydrogen production from electrolytic water is considered as an effective strategy for the preparation of clean energy. Anodic oxygen evolution reaction (OER) is a decisive step for electrolytic water process due to its slow kinetics and excessively high energy barrier. In this work, Prussian blue analogue (PBA) was chosen as a sacrificial template to effectively improve the growth environment of NiFe-based electrocatalysts and V-doped NiSe, FeSe, Fe_4·4Ni_17·6Se₁₆ (FNSe) hybrid electrodes were synthesized using a simple in-situ immersion then multi-step hydrothermal method on a conductive substrate nickel foam (NF). V–NiSe/FeSe/FNSe/NF exhibited a unique nanomicrospheres surface-loaded nanoparticles in a unique morphology. Abundant crystal surface defects and heterojunctions can provide the advantages of a large number of active sites and accelerated electron transfer, which also can lead to the enhancement of catalytic activity, OER (overpotential of 181 mV@10 mA cm⁻²) and UOR (potential of 1.31 V@10 mA cm⁻²). This study provides new ideas for the exploration of transition metal selenide electrocatalysts for electrolytic water.