Controlled Synthesis of Cr‐Co_0.85Se Nanoarrays for Water Splitting at an Ultralow Cell Voltage of 1.43 V

Abstract

Water splitting has attracted more and more attention as a promising strategy for the production of clean hydrogen fuel. In this work, a new synthesis strategy was proposed, and Co0.85Se was synthesized on nickel foam as the main matrix. The doping of appropriate Cr amount into the target of Co0.85Se and the Cr‐Co0.85Se resulted in an excellent electrochemical performance. The doping of Cr introduces Cr3+ ions which substitute Co2+ and Co3+ ions in Co0.85Se, so that the lattice parameters of the main matrix were changed. It is worth noting that the Cr0.15‐Co0.85Se/NF material exhibits an excellent performance in the oxygen evolution reaction (OER) test. When the current density reaches 50 mA cm−2 for OER, the overpotential is only 240 mV. For the hydrogen evolution reaction (HER) tests, the overpotential is only 117 mV to drive 10 mA cm−2 of current density. Moreover, when the Cr0.15‐Co0.85Se/NF material is used as a two‐electrode device for whole water splitting, the required cell voltage is only 1.43 V to reach a current density of 10 mA cm−2, which is among the lowest values of the published catalysts up to now. In addition, the Cr0.15‐Co0.85Se/NF catalyst also exhibits excellent stability during a long period of water splitting. The experimental result demonstrates that the change of the lattice structure has an obvious influence on the electrocatalytic activity of the material. When an external electric field is applied, it facilitates the rapid electron transfer rate and enhances the electrocatalytic performance and stability of the material.

Fabricating a high-performance anode by coating a carbon layer on a yolk–shell bimetallic selenide microsphere for enhanced lithium storage

“…2i displays three peaks at 284.7, 285.4 and 288.1 eV in the high-resolution spectrum of C 1s, which correspond to the CC/C–C, C–N bond and C–O functional group, respectively. 38…”

Recent Developments on Cr‐Based Electrocatalysts for the Oxygen Evolution Reaction in Alkaline Media

“…This performance was improved on by Du et al . wherein they successfully synthesised Cr x Co y Se nanoarrays on Ni foam and noted that a specific composition of Cr 0.15 ‐Co 0.85 Se exhibits the best activity for alkaline OER [54] . The overpotential of the Cr 0.15 ‐Co 0.85 Se/NF demonstrates a low value of 240 mV at 10 mA cm −2 , superior to that of even RuO 2 / NF (340 mV).…”

Built-in electric fields and extra electric fields in the oxygen evolution reaction

“…[41][42][43] External electric elds have the advantages of easy controllability, efficient energy transfer, and wide applicability, showing great potential in catalytic processes, but no working system has summarized the role of electric elds in the OER. [44][45][46] In this work, we classify electric elds into two categories: built-in electric elds and additional electric elds based on their introduction methods. We examine the generation, specic roles, verication methods, and enhancement strategies of built-in electric elds.…”

“…41–43 External electric fields have the advantages of easy controllability, efficient energy transfer, and wide applicability, showing great potential in catalytic processes, but no working system has summarized the role of electric fields in the OER. 44–46…”