Adjusting grain boundary within NiCo2O4rod arrays by phosphating reaction for efficient hydrogen production

In this work, the density and electronic structures of the metal active sites in NiCo₂O₄nanorod arrays were concurrently tuned by controlling the sample's exposure time in a phosphorization process. The results showed that both the density and electronic structure of the active adsorption sites played a key role towards the catalytic activity for water splitting to produce hydrogen. The optimal catalyst exhibited 81 mV overpotential for hydrogen evolution reaction (HER) at 10 mA cm^-2and 313 mV overpotential towards oxygen evolution reaction at 50 mA cm^-2. The assembled electrode delivered a current density of 50 mA cm^-2at 1.694 V in a fully functional water electrolyzer. The further results of theoretical density functional theory calculations revealed the doping of P elements lowered down the H adsorption energies involved in the water splitting process on the various active sites of P-NiCo₂O₄-10 catalyst, and thus enhanced its HER catalytic activities.

Rational Synthesis and Regulation of Hollow Structural Materials for Electrocatalytic Nitrogen Reduction Reaction

The electrocatalytic nitrogen reduction reaction (NRR) is known as a promising mean of nitrogen fixation to mitigate the energy crisis and facilitate fertilizer production under mild circumstances. For electrocatalytic reactions, the design of efficient catalysts is conducive to reducing activation energy and accelerating lethargic dynamics. Among them, hollow structural materials possess cavities in their structures, which can slack off the escape rate of N2 and reaction intermediates, prolong the residence time of N2 , enrich the reaction intermediates' concentration, and shorten electron transportation path, thereby further enhancing their NRR activity. Here, the basic synthetic strategies of hollow structural materials are introduced first. Then, the recent breakthroughs in hollow structural materials as NRR catalysts are reviewed from the perspective of intrinsic, mesoscopic, and microscopic regulations, aiming to discuss how structures affect and improve the catalytic performance. Finally, the future research directions of hollow structural materials as NRR catalysts are discussed. This review is expected to provide an outlook for optimizing hollow structural NRR catalysts.

Chemical Design of Palladium-Based Nanoarchitectures for Catalytic Applications

Palladium (Pd) plays an important role in numerous catalytic reactions, such as methanol and ethanol oxidation, oxygen reduction, hydrogenation, coupling reactions, and carbon monoxide oxidation. Creating Pd-based nanoarchitectures with increased active surface sites, higher density of low-coordinated atoms, and maximized surface coverage for the reactants is important. To address the limitations of pure Pd, various Pd-based nanoarchitectures, including alloys, intermetallics, and supported Pd nanomaterials, have been fabricated by combining Pd with other elements with similar or higher catalytic activity for many catalytic reactions. Herein, recent advances in the preparation of Pd-based nanoarchitectures through solution-phase chemical reduction and electrochemical deposition methods are summarized. Finally, the trend and future outlook in the development of Pd nanocatalysts toward practical catalytic applications are discussed.

Physical vapor deposited highly oriented V2O5 thin films for electrocatalytic oxidation of hydrazine

The proposed work is focused on the effect of substrates on the electrocatalytic performance of physical vapor deposited vanadium pentoxide (V₂O₅) films.

Shape-selective synthesis of NiO nanostructures for hydrazine oxidation as a nonenzymatic amperometric sensor

In this work, we demonstrate the shape-dependent electrocatalytic activity of NiO NPs towards hydrazine oxidation.

Amorphous PtNiP particle networks of different particle sizes for the electro-oxidation of hydrazine

Amorphous PtNiP particle networks with different particle sizes prepared via the reaction temperature control method showed high catalytic activity for hydrazine oxidation compared to the Pt and PtNi catalysts due to its porous, amorphous structure.