Controlled synthesis of NiCoS@Fe6(OH)12(CO3) as efficient electrocatalyst for oxidation reaction in seawater and urea

In today's world, the efficient preparation of clean energy has become a problem for every country. Hydrogen is a very clean and easy to prepare energy source. In this paper, a hybrid materials of Fe-6(OH)(12)(CO3) and sulphide (Ni9S8/Co9S8) was demonstrated as a catalytic electrode for efficient oxidation reaction in seawater and urea. The catalysts were prepared by a three-step hydrothermal-sulfuration-hydrothermal reaction, and the layered composites of hydroxides and sulfides were co-grown into nano-arrays, which exposed more reaction centers and shortened the electron transfer path. The three metal cations were also able to demonstrate different corrosion resistance and excellent adsorption properties for different environments, allowing the catalyst to present better electrochemical activity in seawater as well as in urea solution. In the oxidation reaction in urea solution (1 M KOH+0.5 +0.5 M urea), the required voltage was only 1.33 V at a current intensity of 50 mA/cm(2), and in the water oxidation reaction in seawater, the required voltage was only 1.47 V at a current intensity of 50 mA/cm(2) for Ni9S8@Co9S8@Fe6(OH)(12)(CO3). . Unfortunately, the durability of the catalyst need to be improved, the current density dropped from 40 mA/cm2 2 to 35 mA/cm(2 )and then remained for 12 h. Meanwhile, the comparison of electrochemical performance tests was performed before and after the IT test, it can be clearly seen that the overall performance of Ni9S8@Co9S8@Fe6(OH)(12)(CO3). decreased after the stability test, which may be related to the shedding of active species from the surface of the catalyst. As you can see through density functional theory (DFT) that Ni9S8 can promote the adsorption energy of urea and Co9S8 lowers the barrier to electron conduction. Many conjectures were made and confirmed in this study, and finally, it is hoped that seawater as well as industrial wastewater can be better utilized for the production of clean energy.