Defect-Rich PdIr Bimetallene Nanoribbons with Interatomic Charge Localization for Isopropanol-Assisted Seawater Splitting

Mechanism insight into the N-C polar bond and Pd-Co heterojunction for improved hydrogen evolution activity

Constructing platinum-like materials with excellent catalytic activity and low cost has great significance for hydrogen evolution reaction (HER) during electrolysis of water. Herein, palladium nanoparticles (NPs) deposition on the surface of Co NPs using nitrogen-doped carbon (NC) as substrate, denoted as N-ZIFC/CoPd-30, are manufactured and served as HER electrocatalysts. Characterization results and density functional theory calculations validate that Pd-Co heterojunctions with NC acting as "electron donators" promote the Pd species transiting to the electron-rich state based on an efficient electron transfer mechanism, namely the N-C polar bonds induced strong metal-support interaction effect. The electron-rich Pd sites are beneficial to HER. Satisfactorily, N-ZIFC/CoPd-30 have only low overpotentials of 16, 162, and 13 mV@-10 mA cm-2 with the small Tafel slopes of 98 mV/decade, 126 mV/decade, and 72 mV/decade in pH of 13, 7, and 0, respectively. The success in fabricating N-ZIFC/CoPd opens a promising path to constructing other platinum-like electrocatalysts with high HER activity.

Modification of carbon nanofibers for boosting oxygen electrocatalysis

Oxygen electrocatalysis is a key process for many effective energy conversion techniques, which requires the development of high-performance electrocatalysts. Carbon nanofibers featuring good electronic conductivity, large specific surface area, high axial strength and modulus, and good resistance toward harsh environments have thus been recognized as reinforcements in oxygen electrocatalysis. This review summarizes the recent progress on carbon nanofibers as electrocatalysts for oxygen electrocatalysis, with special focus on the modulation of carbon nanofibers for further elevating their electrocatalytic performance, which includes morphological and structural engineering, surface and pore size distribution, defect engineering, and coupling with other electroactive materials. Additionally, the correlation between the geometrical/electronic structure of their active centers and electrocatalytic activity is systematically discussed. Finally, conclusions and perspectives of this interesting research field are presented, which we hope will provide guidance for the future fabrication of more advanced carbon-fiber-based electrocatalysts.

SOx Functionalized NiOOH Nanosheets Embedded in Ni(OH)2 Microarray for High-Efficiency Seawater Oxidation

A nano-micro heterostructure has been established to address the challenges of selectivity, stress, pitting corrosion, and long-term durability of anodes in unpurified seawater. The heterostructure comprised NiOOH nanosheets embedded within a high surface area Ni(OH)2 microarray, and the surface structure is further functionalized with sulfate (SOx). This cation-selective protective layer impedes chloride (Cl-) diffusion and abstracts H from reaction intermediates, leading to enhanced selectivity and corrosion resistance of the anode. The multilevel porosity within the randomly oriented nanosheets and the underlying support provide short diffusion channels for ions and mass migration, ensuring efficient ion transport and long-term structural and mechanical durability of the active sites, even at high current density. Remarkably, the catalyst requires a small input voltage of 400 mV to deliver a current density of 1 A cm-2 and maintains it for over 168 h without noticeable degradation or hypochlorite formation. Spectroscopic analysis and density functional theory (DFT) calculations reveal that the Ni electronic structure in the +3 valence state, its strong structural interaction with the underlying microarray, and the functionality of SOx significantly reduce the required potential for O-O coupling.

Recent progress of Ni-based nanomaterials for the electrocatalytic oxygen evolution reaction at large current density

The precise design and development of high-performing oxygen evolution reaction (OER) for the production of industrial hydrogen gas through water electrolysis has been a widely studied topic. A profound understanding of the nature of electrocatalytic processes reveals that Ni-based catalysts are highly active toward OER that can stably operate at a high current density for a long period of time. Given the current gap between research and applications in industrial water electrolysis, we have completed a systematic review by constructively discussing the recent progress of Ni-based catalysts for electrocatalytic OER at a large current density, with special focus on the morphology and composition regulation of Ni-based electrocatalysts for achieving extraordinary OER performance. This review will facilitate future research toward rationally designing next-generation OER electrocatalysts that can meet industrial demands, thereby promoting new sustainable solutions for energy shortage and environment issues.

Recent Advances in Hybrid Seawater Electrolysis for Hydrogen Production

Seawater electrolysis (SWE) is a promising and potentially cost-effective approach to hydrogen production, considering that seawater is vastly abundant and SWE is able to combine with offshore renewables producing green hydrogen. However, SWE has long been suffering from technical challenges including the high energy demand and interference of chlorine chemistry, leading electrolyzers to a low efficiency and short lifespan. In this context, hybrid SWE, operated by replacing the energy-demanding oxygen evolution reaction and interfering chlorine evolution reaction (CER) with a thermodynamically more favorable anodic oxidation reaction (AOR) or by designing innovative electrolyzer cells, has recently emerged as a better alternative, which not only allows SWE to occur in a safe and energy-saving manner without the notorious CER, but also enables co-production of value-added chemicals or elimination of environmental pollutants. This review provides a first account of recent advances in hybrid SWE for hydrogen production. The substitutional AOR of various small molecules or redox mediators, in couple with hydrogen evolution from seawater, is comprehensively summarized. Moreover, how the electrolyzer cell design helps in hybrid SWE is briefly discussed. Last, the current challenges and future outlook about the development of the hybrid SWE technology are outlined.

B-Doping-Induced Lattice Expansion of Pd Metallene Nanoribbons for Oxygen Reduction Reaction

Pd-based metallene is regarded as an efficient catalyst in the field of oxygen reduction reaction (ORR) because of its fantastic physicochemical features. The morphological structure control, lattice strain engineering, and electronic structure modulation of Pd-based metallene are effective tactics to enhance its electrocatalytic performance. In this work, we fabricate atomically thin B-doped Pd metallene nanoribbons (B-Pd MNRs) for efficient alkaline ORR. The atomically thin nanoribbon structure of B-Pd MNRs can expose many surface atoms as catalytically active sites. Moreover, the incorporation of boron effectively induces the lattice expansion and modulates the electronic structure of Pd, which can synergistically weaken the adsorption of intermediate species on B-Pd MNRs. Therefore, the B-Pd MNRs display excellent activity and durability for ORR. This work opens an avenue to the synthesis of atomically thin heteroatom-doped metallene nanoribbons for energy electrocatalytic applications.

Engineering metallenes for boosting electrocatalytic biomass-oxidation-assisted hydrogen evolution reaction

Metallenes exhibit great potential for catalytic reaction, particularly for the hydrogen evolution reaction (HER) and biomass oxidation reaction, due to their favorable electronic configurations, ultrahigh specific surface areas, and highly accessible surface atoms. Therefore, metallenes can function as bifunctional electrocatalysts to boost the energy-saving biomass-oxidation-assisted HER, and have attracted great interest. Given the growing importance of green hydrogen as an alternative energy source in recent years, it is timely and imperative to summarize the recent progress and current status of metallene-based catalysts for the biomass-oxidation-assisted HER. Here, we review the recent advances in metallenes in terms of composition and structural regulations including alloying, nonmetal doping, defect engineering, surface functionalization, and heterostructure engineering strategies and their applications in driving electrocatalytic HER, with special focus on biomass-oxidation-assisted hydrogen production. The underlying structure-activity relationship and mechanisms are also comprehensively discussed. Finally, we also propose the challenges and future directions of metallene-based catalysts for the applications in biomass-oxidation-assisted HER.

Pd@PtRuNi core-shell nanowires as oxygen reduction electrocatalysts

Fuel cells, as the alternative to fossil energy, have engaged widespread attention by reason of the high conversion efficiency from the chemical energy to the electric energy combined with low pollution emissions. The cathodic ORR catalysts with excellent performance and cost-effectiveness are the dominant point towards the massive development of fuel cells. Here, our group select the Pd NWs as the template and construct the Pd@PtRuNi core-shell bilayer nanostructure to expand platinum atom utilization. Pd@PtRuNi bilayer core-shell NWs unfold elevated mass activity of1.62Amgmetal-1at 0.9 V versus RHE in alkaline media, 2.03- and 6.23-fold of pristine Pd NWs and benchmark commercial Pt/C, respectively. Meanwhile, the cyclic stability tests reveal the excellent durability of Pd@PtRuNi NWs, whose mass activity is only 13.58% degradation after accelerated durability tests. The catalytic activity and durability towards ORR are better than the U.S. 2025 DOE target (0.44Amgpt-1and less than 40% activity attenuation at 0.9 V after 30 000 potential cycles). The elevated catalytic properties can be traceable to the synergism between the ligand effect of Ni and Ru and one-dimensional structure superiority, which optimizes the electronic structure of active sites, promotes the charge transfer and restrains the agglomeration and detachment.