Driven by the serious ecological problems, it is urgent to explore high-efficiency sustainable energy technologies. Oxygen electrocatalysis acts as important half-reactions in the emerging electrochemical energy techniques including electrolysis and batteries. Gel composites exhibit the merits of rich porous, superior hydrophilic, and large specific surface area, which can significantly improve the electrolyte penetration and boost the kinetics process of oxygen electrocatalysis. In this invited contribution, the advances and challenges of a novel gel materials for oxygen electrocatalysis are summarized. Starting from the structure–activity–performance relationship of gel materials, synthetic routes of nanostructured gel materials, namely, radical polymerization, sol-gel method, hydrothermal/solvothermal reactions, and ligand-substitution method, are introduced. Afterward, the gel composites are divided into polymer-based, metal-based, and carbon-based materials in turn, and their applications in oxygen electrocatalysis are discussed respectively. At the end, the perspective and challenges for advanced gel oxygen electrocatalysts are proposed.

Designing earth-abundant electrocatalysts with high performance towards water oxidation is highly decisive for the sustainable energy technologies. This study develops a facile natural corrosion approach to fabricate nickel-iron hydroxides for water oxidation. The resulted electrode demonstrates an outstanding activity and stability with an overpotential of 275 mV to deliver 10 mA·cm^-2. Experimental and theoretical results suggest the corrosion-induced formation of hydroxides and their transformation to oxyhydroxides would account for this excellent performance. This work not only provides an interesting corrosion approach for the fabrication of excellent water oxidation electrode, but also bridges traditional corrosion engineering and novel materials fabrication, which would offer some insights in the innovative principles for nanomaterials and energy technologies.

Hierarchical FeP nanoarray films composed of FeP nanopetals were successfully synthesized via a bio-inspired hydrothermal route followed by phosphorization. Glycerol, as a crystal growth modifier, plays a significant role in controlling the morphology and structure of the FeO(OH) precursor during the biomineralization process, while the following transfer and pseudomorphic transformation of the FeO(OH) film successfully give rise to the FeP array film. The as-prepared FeP film electrodes exhibit excellent hydrogen evolution reaction (HER) performance over a wide pH range. Theoretical calculations reveal that the mixed P/Fe termination in the FeP film is responsible for the high catalytic activity of the nanostructured electrodes. This new insight will promote further explorations of efficient metal phosphoride-based catalysts for the HER. More importantly, this study bridges the gap between biological and inorganic self-assembling nanosystems and may open up a new avenue for the preparation of functional nanostructures with application in energy devices.

Although nanostructures based on noble metal alloys are widely utilized in (electro)catalysis, their low-temperature synthesis remains an enormous challenge due to the different Nernst equilibrium potentials of metal precursors. Herein, we describe the successful synthesis of trimetallic PtRhNi alloy nanoassemblies (PtRhNi-ANAs) with tunable Pt/Rh ratios using a simple mixed cyanogel reduction method and provide a detailed characterization of their chemical composition, morphology, and structure. Additionally, the electrochemical properties of PtRhNi-ANAs are examined by cyclic voltammetry, revealing composition-dependent electrocatalytic activity in the ethanol oxidation reaction (EOR). Compared to a commercial Pt black electrocatalyst, optimized Pt₃Rh₁Ni₂-ANAs display remarkably enhanced EOR electrocatalytic performance in alkaline media.