Constructing Double-Layer CoP/CeO₂–FeO_xH Hybrid Catalysts for Alkaline and Neutral Water Splitting

Abstract

There is a great challenge in designing bifunctional electrocatalysts with low-cost and high-efficiency for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline and neutral electrolytes. In this work, a double-layer CoP/CeO 2 −FeO x H mixed catalyst is successfully prepared by a two-step electrodeposition process as a bifunctional electrocatalyst in alkaline and neutral solutions. The CoP/CeO 2 −FeO x H catalytic electrode in alkaline and neutral solutions exhibits overpotentials of 37 for HER and 248 for OER at 10 mA cm −2 . The cell voltages of the whole electrolyzed water in alkaline and neutral media are 1.53 and 1.82 V at the current density of 10 mA cm −2 , respectively. Moreover, this catalyst also shows a significant balance between catalytic activity and stability. This work not only provides a new strategy for the preparation of double-layer composite materials but also provides an experimental reference for the industrial development of electrolyzed water in alkaline or neutral solutions.

Boosting Hydrogen Evolution Electrocatalysis via Regulating the Electronic Structure in a Crystalline–Amorphous CoP/CeOx p–n Heterojunction

“…The earth-abundant ceria (CeO 2 ) possesses the high-density oxygen vacancy via reversible redox transformation between Ce 3+ and Ce 4+ and facile ability to hybrid with other components with a strong coupling effect, showing great promise to enhance the electrocatalytic properties of the active materials. − As a typical n-type semiconductor of CeO 2 , the strongly coupled p–n heterointerfaces within CeO 2 /Co 3 O 4 nanotubes contribute to the improvement of the OER performance . Moreover, the crystalline CeO 2 -involved composite materials, including double-layer CoP/CeO 2 –FeO x H hybrid catalyst and CeO 2 /Co 4 N heterostructures, have shown distinguished activity for alkaline HER. , From another point of view, in comparison with the well-documented crystalline–crystalline counterparts, the crystalline–amorphous heterojunctions may combine the merits of the amorphous structure to further enhance the electrocatalytic performance, such as its abundant defects, high flexibility, and better corrosion resistance. Heterostructured CoP@a-CoO x plate with strong nanointerfaces electronic interactions shows favorable HER activity .…”

“…31 Moreover, the crystalline CeO 2 -involved composite materials, including double-layer CoP/CeO 2 − FeO x H hybrid catalyst and CeO 2 /Co 4 N heterostructures, have shown distinguished activity for alkaline HER. 32,33 From another point of view, in comparison with the welldocumented crystalline−crystalline counterparts, the crystalline−amorphous heterojunctions may combine the merits of the amorphous structure to further enhance the electrocatalytic performance, such as its abundant defects, high flexibility, and better corrosion resistance. Heterostructured CoP@a-CoO x plate with strong nanointerfaces electronic interactions shows favorable HER activity.…”

(FeMnCe)-co-doped MOF-74 with significantly improved performance for overall water splitting

“…The result implies stronger electronic interactions between Fe, Mn and Ce after the stability test. 74,75 The percentage of Ce 4+ decreases after the test, which may be due to the reduction of Ce 4+ to Ce 3+ during the OER. 71 More discussion about XPS results for initial FeMn 6 Ce 0.5 -MOF-74/NF can be found in the ESI †.…”

Self-Supporting Co/CeO2 Heterostructures for Ampere-Level Current Density Alkaline Water Electrolysis

“…The characteristic peaks at 782.7 and 797.6 eV originated from Co 2p 3/2 and Co 2p 1/2 of Co 2+ . 51,52 The high-resolution Ce 3d XPS spectrum could be fitted with eight characteristic peaks (Figure 1h). The characteristic peaks at 884.4 and 902.8 eV were attributed to Ce 3+ , and the six peaks at 882.5, 888.9, 898.4, 901.0, 907.0, and 916.8 eV were attributed to Ce 4+ .…”