Accelerating the Hydrogen Evolution Kinetics with a Pulsed Laser-Synthesized Platinum Nanocluster-Decorated Nitrogen-Doped Carbon Electrocatalyst for Alkaline Seawater Electrolysis.

Efficient and durable electrocatalysts for the hydrogen evolution reaction (HER) in alkaline seawater environments are essential for sustainable hydrogen production. Zeolitic imidazolate framework-8 (ZIF-8) is synthesized through pulsed laser ablation in liquid, followed by pyrolysis, producing N-doped porous carbon (NC). NC matrix serves as a self-template, enabling Pt nanocluster decoration (NC-Pt) via pulsed laser irradiation in liquid. NC-Pt exhibits a large surface area, porous structure, high conductivity, N-rich carbon, abundant active sites, low Pt content, and a strong NC-Pt interaction. These properties enhance efficient mass transport during the HER. Remarkably, the optimized NC-Pt-4 catalyst achieves low HER overpotentials of 52, 57, and 53 mV to attain 10 mA cm-2 in alkaline, alkaline seawater, and simulated seawater, surpassing commercial Pt/C catalysts. In a two-electrode system with NC-Pt-4(-)ǀǀIrO2(+) as cathode and anode, it demonstrates excellent direct seawater electrolysis performance, with a low cell voltage of 1.63 mV to attain 10 mA cm-2 and remarkable stability. This study presents a rapid and efficient method for fabricating cost-effective and highly effective electrocatalysts for hydrogen production in alkaline and alkaline seawater environments.

Deciphering the Electronic Coupling Dynamics of Laser-induced Ru/Cu Electrocatalyst for Dual-Side Hydrogen Production and Formic Acid Co-synthesis via DFT Analysis.

Herein, a straightforward approach using pulsed laser technology to synthesize selective hexagonal-close-packed (hcp) Ru nanoparticles attached to Cu nanospheres (Ru/Cu) as bifunctional electrocatalyst for catalyzing the hydrogen evolution reaction (HER) and formaldehyde oxidation reaction (FOR) are reported. Initially, Ru-doped CuO flakes are synthesized using a coprecipitation method followed by transformation into Ru/Cu composites through a strategy involving pulsed laser irradiation in liquid. Specifically, the optimized Ru/Cu-4 composite not only demonstrates a low overpotential of 182 mV at 10 mA·cm-2 for the HER but also an ultralow working potential of 0.078 V (versus reversible hydrogen electrode) for the FOR at the same current density. Remarkably, the FOR∥HER-coupled electrolyzer employing the Ru/Cu-4∥Ru/Cu-4 system achieves H2 production at both electrodes with a cell voltage of 0.42 V at 10 mA·cm-2 while co-synthesizing formic acid. Furthermore, density functional theory analyses elucidate that the superior activity of the Ru/Cu composite originates from optimized adsorption energies of reactive species on the catalyst surfaces during the HER and FOR, facilitated by the synergistic coupling between Ru and Cu. This study presents an alternative strategy for synthesizing highly effective electrocatalytic materials for use in energy-efficient H2 production with the cosynthesis of value-added chemicals suitable for practical applications.

Laser-Regulated Iridium-Diffused Nitrogen-Carbon Sites for Enhanced Hydrazine-Assisted Alkaline Seawater Splitting and Zinc-Hydrazine Batteries.

The current study presents a quick and simple method for synthesizing Ir nanoclusters decorated on an N-doped carbon (NC) matrix via pulsed laser ablation in liquid, followed by pyrolysis. The resulting Ir-NC material acts as a dual-functional electrocatalyst, efficiently facilitating hydrogen generation through the hydrazine oxidation reaction (HzOR) and the hydrogen evolution reaction (HER) in alkaline seawater. The optimized Ir-NC-2 catalyst exhibits a low operating potential of 23 mV versus the reversible hydrogen electrode for HzOR and a remarkably low overpotential of 24 mV for HER, achieving a current density of 10 mA cm-2 in alkaline seawater, surpassing the performance of the Pt/C catalyst. Notably, the Ir-NC-2 catalyst also demonstrates superior dual-functionality in overall hydrazine-assisted seawater splitting, requiring only 0.1 V at 10 mA cm-2 while maintaining stability. Moreover, density functional theory calculations reveal that the strong electronic interaction between the Ir nanoclusters and the NC matrix enhances mass transfer and electron conductivity, significantly boosting HER activity and accelerating the kinetics of hydrazine dehydrogenation. Consequently, the Ir-NC-2 catalyst performs efficiently in a Zn-hydrazine battery, achieving high energy efficiency of 95.5% and demonstrating excellent stability for 120 h (360 cycles), indicating its potential for practical applications.

Architecting the High-Entropy Oxides on 2D MXene Nanosheets by Rapid Microwave-Heating Strategy with Robust Photoelectrochemical Oxygen Evolution Performance.

High-entropy oxides (HEO) have recently concerned interest as the most promising electrocatalytic materials for oxygen evolution reactions (OER). In this work, a new strategy to the synthesis of HEO nanostructures on Ti3 C2 Tx MXene via rapid microwave heating and subsequent calcination at a low temperature is reported. Furthermore, the influence of HEO loading on Ti3 C2 Tx MXene is investigated toward OER performance with and without visible-light illumination in an alkaline medium. The obtained HEO/Ti3 C2 Tx -0.5 hybrid exhibited an outstanding photoelectrochemical OER ability with a low overpotential of 331 mV at 10 mA cm-2 and a small Tafel slope of 71 mV dec-1 , which exceeded that of a commercial IrO2 catalyst (340 mV at 10 mA cm-2 ). In particular, the fabricated water electrolyzer with the HEO/Ti3 C2 Tx -0.5 hybrid as anode required a less potential of 1.62 V at 10 mA cm-2 under visible-light illumination. Owing to the strong synergistic interaction between the HEO and Ti3 C2 Tx MXene, the HEO/Ti3 C2 Tx hybrid has a great electrochemical surface area, many metal active sites, high conductivity, and fast reaction kinetics, resulting in an excellent OER performance. This study offers an efficient strategy for synthesizing HEO-based materials with high OER performance to produce high-value hydrogen fuel.

Laser-Synthesized Co-Doped CuO Electrocatalyst: Unveiling Boosted Methanol Oxidation Kinetics for Enhanced Hydrogen Production Efficiency by In Situ/Operando Raman and Theoretical Analyses.

The present study details the strategic development of Co-doped CuO nanostructures via sophisticated and expedited pulsed laser ablation in liquids (PLAL) technique. Subsequently, these structures are employed as potent electrocatalysts for the anodic methanol oxidation reaction (MOR), offering an alternative to the sluggish oxygen evolution reaction (OER). Electrochemical assessments indicate that the Co-CuO catalyst exhibits exceptional MOR activity, requiring a reduced potential of 1.42 V at 10 mA cm-2 compared to that of pure CuO catalyst (1.57 V at 10 mA cm-2). Impressively, the Co-CuO catalyst achieved a nearly 180 mV potential reduction in MOR compared to its OER performance (1.60 V at 10 mA cm-2). Furthermore, when pairing Co-CuO(+)ǀǀPt/C(-) in methanol electrolysis, the cell voltage required is only 1.51 V at 10 mA cm-2, maintaining remarkable stability over 12 h. This represents a substantial voltage reduction of ≈160 mV relative to conventional water electrolysis (1.67 V at 10 mA cm-2). Additionally, both in situ/operando Raman spectroscopy studies and theoretical calculations have confirmed that Co-doping plays a crucial role in enhancing the activity of the Co-CuO catalyst. This research introduces a novel synthetic approach for fabricating high-efficiency electrocatalysts for large-scale hydrogen production while co-synthesizing value-added formic acid.

A facile synthesis of nano AgBr attached potato-like Ag2MoO4 composite as highly visible-light active photocatalyst for purification of industrial waste-water.

In recent times, silver (Ag) based semiconductors have been gained a lot of attention as photocatalysts for industrial waste-water treatment owing to their strong visible-light absorbing capability and small bandgap energy. Therefore, herein, we have designed and utilized a one-pot hydrothermal approach to the synthesis of nano-sized AgBr covered potato-like Ag2MoO4 composite photocatalysts for the elimination of organic wastes from the aquatic environment. To achieve a high-performance photocatalyst, a sequence of AgBr/Ag2MoO4 composites were acquired with varying CTAB from 1 to 4 mmol. Furthermore, the photocatalytic activity of these photocatalysts was confirmed from decomposing of Rhodamine B (RhB) dye via visible-light elucidation. It can be noticed that AgBr/Ag2MoO4 composites exhibited significantly increased photocatalytic behaviour as compared with pure AgBr and Ag2MoO4. Surprisingly, the AgBr/Ag2MoO4 composite obtained from 2 mmol CTAB was eliminated the entire RhB dye with 25 min. Also, the recycling experiment indicates the AgBr/Ag2MoO4 composite has an excellent photo-stability. Accordingly, the as-acquired AgBr/Ag2MoO4 composite would be a suitable photocatalytic material for industrial waste-water purification.

Hierarchically activated porous carbon derived from zinc-based fluorine containing metal-organic framework as extremely high specific capacitance and rate performance electrode material for advanced supercapacitors.

In this work, a hierarchically activated porous carbon (APC) was synthesized using fluorine-containing metal-organic framework via facile combined carbonization and KOH activation treatments. The influences of activation conditions on the surface structures and electrochemical performance of APC were systematically studied. Afterwards, the electrochemical responses of APC electrode were further assessed from the cyclic voltammetry and galvanostatic charge-discharge examinations by 6 M KOH electrolyte. The as-obtained APC electrode delivered the high specific capacitances of 540.8 and 280 F g-1 at 1 and 500 A g-1, correspondingly with superior capacitance retention of 94% after 250,000 cycles even at 100 A g-1, which is showing that its outstanding capacitance, remarkable rate capacity, and very-long cyclic life. Furthermore, the as-assembled APC-based symmetrical supercapacitor offers a superb energy density of 19 Wh kg-1 at 182 W kg-1, indicating its large-scale application. Thus, this work proposes a potential route to synthesize highly efficient porous carbon material for the future development of energy storage systems.

Couple of Nonpolarized/Polarized Electrodes Building a New Universal Electrochemical Energy Storage System with an Impressive Energy Density.

Herein, we propose a new concept of energy storage system composed of a nonpolarized electrode and a polarized electrode (PPE) with an impressive energy density. It offered nearly 4 times higher energy density than that of carbon-based supercapacitor. Among the suggested potential PPE system, we introduced an electrodeposited nanozinc on the copper foam as the nearly nonpolarized electrode and a Zn-2,5-dihydroxyterephthalic acid (DHTA) metal-organic framework (MOF)-derived activated porous carbon as a nearly polarized electrode in KOH-ZnO electrolyte to constitute the C|Zn PPE system prototype. The C|Zn system achieved an impressive energy density of 84.5 Wh kg-1 at 1000 W kg-1, 4 times higher than that of the C|C supercapacitor. It also shows a high capacitance retention rate of 94.5% at 10 A g-1 after 10 000 cycles. Therefore, the amazing results indicate that the PPE energy system integrates the advantages of supercapacitors and secondary batteries. It will be a promising and effective energy device for higher-performance electric vehicles.