Enhancing Oxygen Evolution Electrocatalysis via the Intimate Hydroxide–Oxide Interface

Abstract

The development of electrocatalysts with high activity and stability for oxygen evolution reaction (OER) is critically important, the one being regarded as the bottleneck process of overall water splitting. Herein, we fulfill significant OER improvement in both activity and stability by constructing a class of Ni(OH)-CeO supported on carbon paper (Ni Ce@CP) with an intimate hydroxide (Ni(OH))-oxide (CeO) interface. Such interface largely promotes the OER activity with a low overpotential of 220 mV at 10 mA cm and a small Tafel slope of 81.9 mV dec in 1 M KOH. X-ray photoelectron spectroscopy analysis shows that the intimate interface induced by the strong electronic interactions between Ni(OH) and CeO involves the modulation of binding strength between intermediates and catalysts, making a great contribution to the OER enhancement. Importantly, such intimate interface structures can be largely maintained even after a long-time stability test. We have further demonstrated that, when pairing the NiCe@CP after phosphorization (P-NiCe@CP), the NiCe@CP and P-NiCe@CP assembly is highly active and stable for overall water splitting with a low voltage of 1.68 V at 25 mA cm and negligible stability delay over 30 h of continuous operation, which are much better than the commercial Ir/C and Pt/C.

Electrodeposition of Unary Oxide on a Bimetallic Hydroxide as a Highly Active and Stable Catalyst for Water Oxidation

“…18,24 In this scenario, the ratio Ni 2+ /Ni 3+ in CeO x /NiFe-OH (0.81) was slightly changed in comparison with that in bare NiFe-OH (0.89), which was denoted as the highest concentration of Ni 3+ in CeO x /NiFe-OH catalysts. 24 In the Fe 2p XPS spectra (Figure 2d), peaks were observed at ∼724.6 eV (2p 3/2 ) and ∼711.7 eV (2p 1/2 ), without dramatic changes in the line shape and peak position, confirming the presence of the Fe species as Fe 3+ in both catalysts. 17,34 Figure 2e shows the deconvoluted XPS spectra of Ce 3d.…”

Zeolitic Imidazolate Framework‐Derived Core‐Shell‐Structured CoS2/CoS2‐N‐C Supported on Electrochemically Exfoliated Graphene Foil for Efficient Oxygen Evolution

“…The same conclusion could also be drawn from the inset amperometric i‐t curve of EG/CoS 2 /CoS 2 ‐NC, where the current density remains 30.9 mA cm −2 at 1.6 V for 10 h, indicating a robust durability of EG/CoS 2 /CoS 2 ‐NC electrode. Such an impressive stability may be attributed to the protection from the carbon shells during the OER procedure.…”

Mesoporous cerium oxide-coated upconversion nanoparticles for tumor-responsive chemo-photodynamic therapy and bioimaging

“…Hence, cerium oxide NPs can achieve O 2 compensation to continuously generate O 2 and provide an O 2 environment for PDT and chemotherapy, thus improving cancer treatment efficiency. [37][38][39] As a semiconductor catalyst, cerium oxide has a relatively unusual specic surface area, which effectively enhances the light capturing ability of the material. The defects on its grain surface and abundant O 2 vacancies further enhance its catalytic ability and the use of visible light.…”