Engineering P-Fe2O3-CoP nanosheets for overall freshwater and seawater splitting

Synergizing RuO2 with Fe-doped Co2RuO4 for boosting alkaline electrocatalytic oxygen evolution reaction

Designing and development of electrocatalysts with high catalytic capacity and stability for oxygen evolution reaction (OER) is significant for sustainable water splitting. In this study, we rationally designed Fe-doped Co2RuO4/RuO2 heterostructure electrocatalysts on nickel foam (NF) through mixture hydrothermal, ion exchanging, and calcining methods. The synergistic effect between the Fe-Co2RuO4/RuO2 heterogeneous interfaces can result in superior inherent activity. Meanwhile, the unique nanosheet on nanosheet structure delivers abundant exposed active sites, leading to improved catalytic activity. The resultant Fe-Co2RuO4/RuO2 heterostructured catalysts possessed superior OER property, attaining a current density of 50 mA cm-2 with only 253 mV overpotential in 1.0 M KOH alkaline solution, and demonstrating good durability with continuous operation for up to 50 h. This research provides robust support for the research and development of RuO2-based electrocatalysts through effective interface engineering and doping strategies, and opens up new avenues for the industrial application of water splitting technology.

Applications of Ferric Oxide in Water Splitting by Electrolysis: A Comprehensive Review

In water electrolysis, the use of an efficient catalyst derived from earth-abundant materials which is cost-effective and stable is essential for the economic sustainability of hydrogen production. A wide range of catalytic materials have been reported upon so far, among which Fe2O3 stands out as one of the most credible candidates in terms of cost and abundance. However, Fe2O3 faces several limitations due to its poor charge transfer properties and catalytic ability; thus, significant modifications are essential for its effective utilization. Considering the future of water electrolysis, this review provides a detailed summary of Fe2O3 materials employed in electrolytic applications with a focus on critically assessing the key electrode modifications that are essential for the materials' utilization as efficient electrocatalysts. With this in mind, Fe2O3 was implemented in a heterojunction/composite, doped, carbon supported, crystal facet tuned system, as well as in metal organic framework (MOF) systems. Furthermore, Fe2O3 was utilized in alkaline, seawater, anion exchange membrane, and solid oxide electrolysis systems. Recently, magnetic field-assisted water electrolysis has also been explored. This comprehensive review highlights the fact that the applicability of Fe2O3 in electrolysis is limited, and hence, intense and strategically focused research is vital for converting Fe2O3 into a commercially viable, cost-effective, and efficient catalyst material.

In Situ Fast Construction of Ni3S4/FeS Catalysts on 3D Foam Structure Achieving Stable Large-Current-Density Water Oxidation

By increasing the content of Ni3+, the catalytic activity of nickel-based catalysts for the oxygen evolution reaction (OER), which is still problematic with current synthesis routes, can be increased. Herein, a Ni3+-rich of Ni3S4/FeS on FeNi Foam (Ni3S4/FeS@FNF) via anodic electrodeposition to direct obtain high valence metal ions for OER catalyst is presented. XPS showed that the introduction of Fe not only further increased the Ni3+ concentration in Ni3S4/FeS to 95.02%, but also inhibited the dissolution of NiOOH by up to seven times. Furthermore, the OER kinetics is enhanced by the combination of the inner Ni3S4/FeS heterostructures and the electrochemically induced surface layers of oxides/hydroxides. Ni3S4/FeS@FNF shows the most excellent OER activity with a low Tafel slope of 11.2 mV dec-1 and overpotentials of 196 and 445 mV at current densities of 10 and 1400 mA cm-2, respectively. Furthermore, the Ni3S4/FeS@FNF catalyst can be operated stably at 1500 mA cm-2 for 200 h without significant performance degradation. In conclusion, this work has significantly increased the high activity Ni3+ content in nickel-based OER electrocatalysts through an anodic electrodeposition strategy. The preparation process is time-saving and mature, which is expected to be applied in large-scale industrialization.