RuO₂-NiO Nanosheets on Conductive Nickel Foam for Reliable and Regeneratable Seawater Splitting

Abstract

Exploration of active and durable electrocatalysts for water splitting has aroused widespread concern and is devoted with huge efforts to produce sustainable energy: hydrogen. Herein, selfstanding RuO 2 -NiO nanosheets on conductive nickel foam (RuO 2 -NiO NSs/NF) are obtained via a spontaneous coprecipitation strategy for the hydrogen evolution reaction (HER). The RuO 2 -NiO NSs/NF electrode not only has efficient intrinsic activity because of the in situ-formed Ru/RuO 2 interface during HER but also presents superior kinetic stability due to the self-standing nanosheet structure. By integrating compositional and structural merits, the RuO 2 -NiO NSs/NF electrode displays higher turnover frequencies compared with Pt/C (0.524 vs 0.376 H 2 s −1 in 1 M KOH and 0.177 vs 0.065 H 2 s −1 in 1 M KPi) and delivers remarkably small overpotentials of 14 and 25 mV at 10 mA cm −2 in 1 M KOH and KPi, respectively. Along with long-term stability at large current densities and excellent regenerative capability with simple acid treatment, the RuO 2 -NiO NSs/NF electrode exhibits potential for commercial seawater splitting.

Designing binary electrocatalysts for hydrogen evolution in saline electrolyte using rapid synthesis on carbon paper supports

“…7 Non-precious metal electrocatalysts have emerged as promising alternatives for HER due to their low cost, abundance, and potential for high activity. [9][10][11][12][13][14][15] In recent years, significant progress has been made in developing efficient and stable nonprecious metal electrocatalysts for HER in acidic and alkaline conditions. 16,17 However, these electrocatalysts have not been extensively tested in the challenging conditions of low-grade water sources, such as seawater, which presents a highly complex corrosive environment.…”

RuO2 Nanostructure as an Efficient and Versatile Catalyst for H2 Photosynthesis

“…Other noble metals demonstrated activity in HER, , and among them, ruthenium, which is at least 6 times cheaper than Pt, has already been employed in 1979, but it gained greater attention only in the last few years, showing HER overpotential at 10 mA cm –2 very close to that of Pt. , Moreover, the oxides of Pt group metals are widely used as an oxygen evolution catalyst (OEC), − but some of them also showed good activity in HER . In particular, ruthenium (IV) oxide (RuO 2 ) has been extensively studied as an OEC, − scarcely for H 2 evolution, and mostly as an electro- ,− or a photoelectro-HEC, − but it is growing as demonstrated by the increasing number of papers since the last 10 years (Figure S1). The RuO 2 -based electrodes and nanoparticles (Nps) are exploited as a HEC by applying an external bias to induce metal reduction and thus favoring the formation of Ru–H bonds and consequent H 2 evolution. , Several examples in which Ru or RuO 2 Nps are supported on other metal oxides and employed as colloidal dispersion for H 2 or O 2 evolution demonstrated improved activity, stability, and recoverability. ,,,, …”

Designing Electrocatalysts for Hydrogen Evolution in Saline Electrolyte Using Rapid Synthesis on Carbon Paper Supports

“…[7] Non-precious metal electrocatalysts have emerged as promising alternatives for HER due to their low cost, abundance, and potential for high activity. [9][10][11][12][13][14][15] In recent years, significant progress has been made in developing efficient and stable nonprecious metal electrocatalysts for HER in acidic and alkaline conditions. [16,17] However, these electrocatalysts have not been extensively tested in the challenging conditions of low-grade water sources, such as seawater, which presents a highly complex corrosive environment.…”