Multifunctional nickel sulfide superstructures (h‐NiSx) with 3D hierarchically porosity are prepared by template‐free electrodeposition of porous metallic Ni microspheres arrays on a nickel foam and ...subsequent low‐temperature sulfurization. With the designed nanoscale architecture, the resulting h‐NiSx exhibit superior performance and strong robustness for overall water splitting electrocatalysis and capacitance application in alkaline electrolytes.
One of the challenges to realize large‐scale water splitting is the lack of active and low‐cost electrocatalysts for its two half reactions: H2 and O2 evolution reactions (HER and OER). Herein, we ...report that cobalt‐phosphorous‐derived films (Co‐P) can act as bifunctional catalysts for overall water splitting. The as‐prepared Co‐P films exhibited remarkable catalytic performance for both HER and OER in alkaline media, with a current density of 10 mA cm−2 at overpotentials of −94 mV for HER and 345 mV for OER and Tafel slopes of 42 and 47 mV/dec, respectively. They can be employed as catalysts on both anode and cathode for overall water splitting with 100 % Faradaic efficiency, rivalling the integrated performance of Pt and IrO2. The major composition of the as‐prepared and post‐HER films are metallic cobalt and cobalt phosphide, which partially evolved to cobalt oxide during OER.
Split and polished: Electrodeposited cobalt‐phosphorous‐derived films (Co‐P) can act as superior bifunctional catalysts for overall water splitting. When employed as catalysts on both the anode and cathode for water electrolysis, the Co‐P/Co‐P catalyst couple can rival the integrated performance of IrO2 and Pt in alkaline media. Such a bifunctional Co‐P film is a promising catalyst candidate for overall water‐splitting electrolysis.
Fuel cells are an incredibly powerful renewable energy technology, but their broad applications remains lagging because of the high cost and poor reliability of cathodic electrocatalysts for the ...oxygen reduction reaction (ORR). This review focuses on the recent progress of ORR electrocatalysts in fuel cells. More importantly, it highlights the fundamental problems associated with the insufficient activity translation from rotating disk electrode to membrane electrode assembly in the fuel cells. Finally, for the atomic‐level in‐depth information on ORR catalysts in fuel cells, potential perspectives are suggested, including large‐scale preparation, unified assessment criteria, advanced interpretation techniques, advanced simulation and artificial intelligence. This review aims to provide valuable insights into the fundamental science and technical engineering for efficient ORR electrocatalysts in fuel cells.
Fuel cells are a powerful renewable energy technology. This review gives a comprehensive overview on oxygen reduction electrocatalysts towards practical fuel cells.
The design of active, robust, and nonprecious electrocatalysts with both H2 and O2 evolution reaction (HER and OER) activities for overall water splitting is highly desirable but remains a grand ...challenge. Herein, we report a facile two-step method to synthesize porous Co-P/NC nanopolyhedrons composed of CoP x (a mixture of CoP and Co2P) nanoparticles embedded in N-doped carbon matrices as electrocatalysts for overall water splitting. The Co-P/NC catalysts were prepared by direct carbonization of Co-based zeolitic imidazolate framework (ZIF-67) followed by phosphidation. Benefiting from the large specific surface area, controllable pore texture, and high nitrogen content of ZIF (a subclass of metal–organic frameworks), the optimal Co-P/NC showed high specific surface area of 183 m2 g–1 and large mesopores, and exhibited remarkable catalytic performance for both HER and OER in 1.0 M KOH, affording a current density of 10 mA cm–2 at low overpotentials of −154 mV for HER and 319 mV for OER, respectively. Furthermore, a Co-P/NC-based alkaline electrolyzer approached 165 mA cm–2 at 2.0 V, superior to that of Pt/IrO2 couple, along with strong stability. Various characterization techniques including X-ray absorption spectroscopy (XAS) revealed that the superior activity and strong stability of Co-P/NC originated from its 3D interconnected mesoporosity with high specific surface area, high conductivity, and synergistic effect of CoP x encapsulated within N-doped carbon matrices.
Electrochemical water splitting driven by sustainable energy such as solar, wind, and tide is attracting ever‐increasing attention for sustainable production of clean hydrogen fuel from water. ...Leveraging these advances requires efficient and earth‐abundant electrocatalysts to accelerate the kinetically sluggish hydrogen and oxygen evolution reactions (HER and OER). A large number of advanced water‐splitting electrocatalysts have been developed through recent understanding of the electrochemical nature and engineering approaches. Specifically, strain engineering offers a novel route to promote the electrocatalytic HER/OER performances for efficient water splitting. Herein, the recent theoretical and experimental progress on applying strain to enhance heterogeneous electrocatalysts for both HER and OER are reviewed and future opportunities are discussed. A brief introduction of the fundamentals of water‐splitting reactions, and the rationalization for utilizing mechanical strain to tune an electrocatalyst is given, followed by a discussion of the recent advances on strain‐promoted HER and OER, with special emphasis given to combined theoretical and experimental approaches for determining the optimal straining effect for water electrolysis, along with experimental approaches for creating and characterizing strain in nanocatalysts, particularly emerging 2D nanomaterials. Finally, a vision for a future sustainable hydrogen fuel community based on strain‐promoted water electrolysis is proposed.
The recent theoretical and experimental progress of applying strain to enhance heterogeneous electrocatalysts for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) is reviewed. Materials ranging from 0D nanoparticles to 1D nanowires/nanotubes, and 2D nanosheets are discussed. It is shown that elastic strain enriches the toolbox for improving electrocatalysts, particularly for the HER and OER.
The development of high-performance nonprecious electrocatalysts with both H2 and O2 evolution reaction (HER and OER) activities for overall water splitting is highly desirable but remains a grand ...challenge. Herein, we report a facile two-step method to synthesize three-dimensional hierarchically porous urchin-like Ni2P microsphere superstructures anchored on nickel foam (Ni2P/Ni/NF) as bifunctional electrocatalysts for overall water splitting. The Ni2P/Ni/NF catalysts were prepared by template-free electrodeposition of porous nickel microspheres on nickel foam followed by phosphidation. The hierarchically macroporous superstructures with 3D configuration can reduce ion transport resistance and facilitate the diffusion of gaseous products (H2 and O2). The optimal Ni2P/Ni/NF exhibited remarkable catalytic performance and outstanding stability for both the HER and OER in alkaline electrolyte (1.0 M KOH). For the HER, Ni2P/Ni/NF afforded a current density of 10 mA cm–2 at a low overpotential of only −98 mV. When it served as an OER electrocatalyst, Ni2P/Ni/NF was partially oxidized to nickel oxides/hydroxides/oxyhydroxides (mainly NiO) on the catalyst surface and exhibited excellent OER activity with small overpotentials of 200 and 268 mV to reach 10 and 100 mA cm–2, respectively. Furthermore, when Ni2P/Ni/NF was employed as the electrocatalyst for both the cathode and anode, a water splitting electrolyzer was able to reach 10 and 100 mA cm–2 in 1.0 M KOH at cell voltages of 1.49 and 1.68 V, respectively, together with robust durability. Various characterization techniques and controlled experiments indicated that the superior activity and strong stability of Ni2P/Ni/NF for overall water splitting originated from its electrochemically active constituents, 3D interconnected porosity, and high conductivity.
Available targeted therapies for esophageal squamous cell carcinoma (ESCC) are limited; thus, further genetic and epigenetic studies are needed. Recently, many long noncoding RNAs (lncRNAs) have been ...reported to be involved in various cancers. Here, we investigated whether the lncRNA LUCAT1 was related to the carcinogenesis of ESCC based on previous studies in lung cancer. LUCAT1 was significantly upregulated in ESCC cell lines and cancer tissue compared with normal cells and adjacent normal tissues. LUCAT1 knockdown reduced cell proliferation, induced apoptosis, and upregulated tumor-suppressor genes by reducing DNA methylation in KYSE-30 cells. Moreover, LUCAT1 siRNA reduced DNA methyltransferase 1 (DNMT1) protein levels without affecting transcription. Patients with high LUCAT1 expression had significantly lower survival rates than patients with low LUCAT1 expression. Our results thus suggest that LUCAT1 regulates the stability of DNMT1 and inhibits the expression of tumor suppressors through DNA methylation, leading to the formation and metastasis of ESCC. We identified LUCAT1 as a potential target for drug development and as a biomarker for ESCC.
•We investigated whether the lncRNA LUCAT1 was related to the carcinogenesis of ESCC.•LUCAT1 was significantly upregulated in ESCC cell lines and tissues.•LUCAT1 modulated cell proliferation, apoptosis, and tumor-suppressor genes in ESCC.•LUCAT1 regulated the stability of DNMT1.•We identified LUCAT1 as a potential drug target and biomarker for ESCC.
Electroreduction of small molecules such as H2O, CO2, and N2 for producing clean fuels or valuable chemicals provides a sustainable approach to meet the increasing global energy demands and to ...alleviate the concern on climate change resulting from fossil fuel consumption. On the path to implement this purpose, however, several scientific hurdles remain, one of which is the low energy efficiency due to the sluggish kinetics of the paired oxygen evolution reaction (OER). In response, it is highly desirable to synthesize high‐performance and cost‐effective OER electrocatalysts. Recent advances have witnessed surface reconstruction engineering as a salient tool to significantly improve the catalytic performance of OER electrocatalysts. In this review, recent progress on the reconstructed OER electrocatalysts and future opportunities are discussed. A brief introduction of the fundamentals of OER and the experimental approaches for generating and characterizing the reconstructed active sites in OER nanocatalysts are given first, followed by an expanded discussion of recent advances on the reconstructed OER electrocatalysts with improved activities, with a particular emphasis on understanding the correlation between surface dynamics and activities. Finally, a prospect for clean future energy communities harnessing surface reconstruction‐promoted electrochemical water oxidation will be provided.
During water splitting, the water oxidation condition reconstructs the electrocatalyst surface and concurrently enhances the performance and durability. To address the surface dynamics of the electrocatalyst and importance of reconstruction process under oxygen evolution reaction (OER) condition, in this review, the fundamentals of OER, origin of surface reconstruction, and comprehensive discussion on the experimental approaches for the electrocatalyst surface reconstruction are presented.
Developing robust electrocatalysts and advanced devices is important for electrochemical carbon dioxide (CO2) reduction toward the generation of valuable chemicals. We present herein a ...carbon‐confined indium oxide electrocatalyst for stable and efficient CO2 reduction. The reductive corrosion of oxidative indium to the metallic state during electrolysis could be prevented by carbon protection, and the applied carbon layer also optimizes the reaction intermediate adsorption, which enables both high selectivity and activity for CO2 reduction. In a liquid‐phase flow cell, the formate selectivity exceeds 90 % in a wide potential window from −0.8 V to −1.3 V vs. RHE. The continuous production of ca. 0.12 M pure formic acid solution is further demonstrated at a current density of 30 mA cm−2 in a solid‐state electrolyte mediated reactor. This work provides significant concepts in the parallel development of electrocatalysts and devices for carbon‐neutral technologies.
A robust carbon‐covered indium oxide electrocatalyst demonstrates an enhanced and stable activity for the direct production of formic acid in a solid‐state carbon dioxide electrolyzer.
Efficient, stable, and low‐cost electrocatalysts are crucial for realizing large‐scale water splitting. Herein, we report that electrodeposited nickel–phosphorous (Ni–P) films can act as efficient ...bifunctional electrocatalysts for overall water splitting. The as‐prepared Ni–P films exhibit remarkable catalytic performance for both H2 and O2 evolution reactions (HER and OER) in alkaline media, achieving a current density of 10 mA cm−2 at overpotentials of −93 mV for HER and 344 mV for OER with Tafel slopes of 43 and 49 mV dec−1, respectively, rivaling the performance of Pt and IrO2. Various techniques were employed to probe the composition and morphology of the Ni–P films prior to and post catalysis, revealing the major composition of the as‐prepared and post‐HER films as metallic nickel and nickel phosphide, which partially transform to nickel oxides during OER. It was also found that the catalytic rate of OER catalyzed by Ni–P was first order in the activity of the hydroxide anion.
Overall water splitting: Electrodeposited nickel–phosphorous films (Ni–P) function as efficient bifunctional catalysts for overall water splitting under strong alkaline conditions, rivalling the performance of the state‐of‐the‐art catalysts, Pt and IrO2.
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