Ni(OH)2 nanoparticles encapsulated in conductive nanowire array for high-performance alkaline seawater oxidation

Electrochemical water splitting represents one of the most promising technologies to produce green hydrogen, which can help to realize the goal of achieving carbon neutrality. While substantial efforts on a laboratory scale have been made for understanding fundamental catalysis and developing high-performance electrocatalysts for the two half-reactions involved in water electrocatalysis, much less attention has been paid to doing relevant research on a larger scale. For example, few such researches have been done on an industrial scale. Herein, we review the very recent endeavors to bridge the gaps between fundamental research and industrial applications for water electrolysis. We begin by introducing the fundamentals of electrochemical water splitting and then present comparisons of testing protocol, figure of merit, catalyst of interest, and manufacturing cost for laboratory and industry-based water-electrolysis research. Special attention is paid to tracking the surface reconstruction process and identifying real catalytic species under different testing conditions, which highlight the significant distinctions of corresponding electrochemical reconstruction mechanisms. Advances in catalyst designs for industry-relevant water electrolysis are also summarized, which reveal the progress of moving the practical applications forward and accelerating synergies between material science and engineering. Perspectives and challenges of electrocatalyst design strategies are proposed finally to further bridge the gaps between lab-scale research and large-scale electrocatalysis applications. 

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/eem2.12441

Electrochemical Water Splitting: Bridging the Gaps between Fundamental Research and Industrial Applications

The control in synthesis and composition plays a vital role in exploring cost-effective efficient electrocatalysts for water splitting. This paper reported a glycerol-assisted solvothermal strategy to synthesize Ru-based electrocatalyst (Ru-G/CC), in-situ growing Ru nanoparticles (NPs) on carbon cloth (CC). The optimal Ru-G/CC exhibits a boosted HER activity (overpotential of 40 mV @ 10 mA cm−2, Tafel slope 76 mV dec−1), surpassing benchmark 20 wt% Pt/C; experimental characterization and DFT calculations verified that Ru NPs with a mixed amorphous/crystalline structure in Ru-G/CC effectively decrease the reaction energy barrier in HER. Also, the hydrothermally derived Ru-H2O/CC-350 exhibited a high electrocatalytic OER activity (overpotential of 270 mV @ 10 mA cm−2, Tafel slope 63 mV dec−1), exceeding the commercial RuO2. This work provides a successful story via regulating synthetic parameters to design efficient and stable Ru-based electrocatalysts for water splitting. 

In-Situ Growth of Ruthenium-Based Nanostructure on Carbon Cloth for Superior Electrocatalytic Activity towards HER and OER

Amorphous/Crystalline Heterostructure Transition-Metal-based Catalysts for High-Performance Water Splitting

/pdf/anion-exchange-membrane-water-electrolyzer-electrode-design-w7fk01oa.pdf

Anion Exchange Membrane Water Electrolyzer: Electrode Design, Lab-Scaled Testing System and Performance Evaluation

For industrial high-purity hydrogen production, it is essential to develop low-cost, earth-abundant, highly-efficient, and stable electrocatalysts which deliver high current density (j) at low overpotential (η) for oxygen evolution reaction (OER). Herein, we report an active mesoporous Ni 2 P @ FePO x H y pre-electrocatalyst, which delivers high j = 1 A cm −2 at η = 360 mV in 1 M KOH with long-term durability (12 days), fulfilling all the desirable commercial criteria for OER. The electrocatalyst shows abundant interfaces between crystalline metal phosphide and amorphous phosphorus-doped metal-oxide, improving charge transfer capability and providing access to rich electroactive sites. Combined with an excellent non-noble metal-based HER catalyst, we achieve commercially required j = 500/1000 mA cm −2 at 1.65/1.715 V for full water-splitting with excellent stability in highly corrosive alkaline environment (30% KOH). The alkaline-anion-exchange-membrane water-electrolyzer (AAEMWE) fabricated for commercial viability exhibits high j of 1 A cm −2 at 1.84 V with long-term durability as an economical hydrogen production method, outperforming the state-of-the-art Pt/C – IrO 2 catalyst. • Noble-metal free catalysts for oxygen evolution reactions are investigated. • Crystalline (Ni 2 P) and amorphous (FePO x H y ) phases in Ni 2 P @ FePO x H y catalyst provide more electrocatalytic active sites. • The Ni 2 P @ FePO x H y catalyst shows excellent AAEMWE cell performance with a low overpotential and good stability. • The Ni 2 P @ FePO x H y catalyst exhibits a low overpotential of 360 mV for OER to deliver a high current density of 1 A cm −2 . 

Crystalline-amorphous interface of mesoporous Ni2P@FePOxHy for oxygen evolution at high current density in alkaline-anion-exchange-membrane water-electrolyzer

In this study, the effects of heat treatment on the physical properties of polypropylene (PP) composites with bamboo fiber (BF) treated by silane coupling agent were investigated. The silane coupling agent was (3-mercaptopropyl)trimethoxysilane (MRPS). Heat treatment (curing step) at 25, 80, 110, 130, 150, and 170 oC was applied to induce chemical bonding between the hydroxyl group (-OH) present on the surface of BF and the hydroxyl group (-OH) of the hydrolyzed silane. The chemical structures of BF were analyzed by FTIR and XPS. The thermal stability, tensile and flexural strength were improved after applying heat treatment, and the optimum results were obtained when the heat treatment temperature was the range of 110-130 oC.

Effects of Heat Treatment on the Physical Properties of PP Composites with Bamboo Fiber Treated by Silane

In order to investigate the effect of the chemical treatment of bamboo fiber on physical properties of polypropylene (PP)/bamboo fiber (BF) composites, silane coupling agents such as γ-aminopropyltriethoxysilane (APS), γ-glycidoxypropyltrimethoxysilane (GPS) and γ-mercaptopropyltrimethoxysilane (MRPS) were applied to BF and alkaline treated BF. Morphological properties of the chemically treated BF were confirmed by optical microscope and SEM measurements, and chemical structure changes were confirmed by FT-IR and EDS. TGA results showed that the thermal stability of silane treated BF increased. Based on the analysis of a universal testing machine and an Izod impact test, the flexural and impact properties of PP/silane treated BF composites showed higher values than those of PP/BF composites. The enhancement of interfacial adhesion properties of the PP/BF composite was checked from SEM images of the fracture of specimens after the tensile test.

Da Sol Jeong

Papers

Crystalline-amorphous interface of mesoporous Ni2P@FePOxHy for oxygen evolution at high current density in alkaline-anion-exchange-membrane water-electrolyzer

Effects of Heat Treatment on the Physical Properties of PP Composites with Bamboo Fiber Treated by Silane

Influence of the Chemical Treatment of Bamboo Fiber (BF) on Physical Properties of BF and PP/BF Composites