scholarly journals Three-Dimensional Flower-like Fe, C-doped-MoS2/Ni3S2 Heterostructures Spheres for Accelerating Electrocatalytic Oxygen and Hydrogen Evolution

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 340
Author(s):  
Xuefeng Lv ◽  
Guangsheng Liu ◽  
Song Liu ◽  
Wenting Chen ◽  
Dehua Cao ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Electrical Transport ◽  
Rational Design ◽  
High Efficiency ◽  
Three Dimensional ◽  
Metal Sulfide ◽  
Molybdenum Sulfide ◽  
Alkaline Media ◽  
Energy Storage And Conversion ◽  
Alkaline Electrolyte

The exploration of high-efficiency bifunctional electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) has long been challenging. The rational design of a catalyst by constructing heterostructures and a doping element are possibly expected to achieve it. Herein, the utilization of flower-like Fe/C-doped-MoS2/Ni3S2-450 spherical structural materials for electrocatalytic HER and OER is introduced in this study. The carboxyferrocene-incorporated molybdenum sulfide/nickel sulfide (MoySx/NiS) nanostructures were prepared by solvothermal method. After annealing, the iron and carbon elements derived from ferrocenecarboxylic acid enhanced the electrical transport performance and provided rich electronic sites for HER and OER in alkaline media. Specifically, the optimized flower-like Fe/C-doped-MoS2/Ni3S2-450 exhibited efficient bifunctional performance in alkaline electrolyte, with low overpotentials of 188 and 270 mV required to deliver a current density of 10 mA cm−2 for HER and OER, respectively. This work provides valuable insights for the rational design of energy storage and conversion materials by the incorporation of transition metal and carbon elements into metal sulfide structures utilizing metallocene.

scholarly journals Comprehensive Evaluation of Transition Metal Doped Ni3N to Construct High-Efficiency Hydrogen Evolution Catalyst

2021 ◽  
Author(s):  
Meng Wang ◽  
Zepeng Lv ◽  
Xuewei Lv ◽  
Qian Li ◽  
Jie Dang
Keyword(s):  
Transition Metal ◽  
Hydrogen Evolution ◽  
Density Functional ◽  
Rational Design ◽  
Dft Calculation ◽  
High Efficiency ◽  
Comprehensive Evaluation ◽  
Low Cost ◽  
Alkaline Electrolyte ◽  
Metal Doped

Abstract Density functional theory (DFT) calculation indicators (ΔG, densities of state, D-band and bader charge) are commonly used to predict and analyze the hydrogen evolution reaction (HER) activity of catalysts, and most studies discuss only one or few of these indicators’ impact on catalysis, but still no report has comprehensively evaluated the influence of all these indicators on catalytic performance. Herein, foreseen by comprehensive consideration first, we report transition metal doped Ni3N nanosheets combined on Ni foam for utra-efficient alkaline hydrogen evolution. For dual transition metals doped Ni3N, Co,V-Ni3N exhibits remarkable HER performance with a significantly low overpotential of only 10 mV in alkaline electrolyte and 41 mV in alkaline seawater electrolyte at 10 mA cm− 2; while for single transition metal doped Ni3N, V-Ni3N exhibits the best performance with an overpotential of 15 mV and a Tafel slope of 37 mV dec− 1. Our work highlights the importance of comprehensive evaluation of DFT calculation indexes, and opens up a new method for the rational design of efficient and low-cost catalysts.

scholarly journals Self-ordered nanospike porous alumina fabricated under a new regime by an anodizing process in alkaline media

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mana Iwai ◽  
Tatsuya Kikuchi ◽  
Ryosuke O. Suzuki
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Porous Alumina ◽  
Three Dimensional ◽  
Alkaline Media ◽  
Alkaline Electrolyte ◽  
Subsequent Formation ◽  
Interpore Distance ◽  
Wide Range ◽  
Ordered Porous

AbstractHigh-aspect ratio ordered nanomaterial arrays exhibit several unique physicochemical and optical properties. Porous anodic aluminum oxide (AAO) is one of the most typical ordered porous structures and can be easily fabricated by applying an electrochemical anodizing process to Al. However, the dimensional and structural controllability of conventional porous AAOs is limited to a narrow range because there are only a few electrolytes that work in this process. Here, we provide a novel anodizing method using an alkaline electrolyte, sodium tetraborate (Na2B4O7), for the fabrication of a high-aspect ratio, self-ordered nanospike porous AAO structure. This self-ordered porous AAO structure possesses a wide range of the interpore distance under a new anodizing regime, and highly ordered porous AAO structures can be fabricated using pre-nanotexturing of Al. The vertical pore walls of porous AAOs have unique nanospikes measuring several tens of nanometers in periodicity, and we demonstrate that AAO can be used as a template for the fabrication of nanomaterials with a large surface area. We also reveal that stable anodizing without the occurrence of oxide burning and the subsequent formation of uniform self-ordered AAO structures can be achieved on complicated three-dimensional substrates.

Well-dispersed molybdenum nitrides on a nitrogen-doped carbon matrix for highly efficient hydrogen evolution in alkaline media

2017 ◽  
Vol 5 (39) ◽  
pp. 20932-20937 ◽  
Author(s):  
Zhe Lv ◽  
Muhammad Tahir ◽  
Xuewei Lang ◽  
Gang Yuan ◽  
Lun Pan ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Carbon Matrix ◽  
Alkaline Media ◽  
Alkaline Electrolyte ◽  
Nitrogen Doped ◽  
Highly Efficient ◽  
Molybdenum Nitrides ◽  
Nitrogen Doped Carbon

A strategy is designed to fabricate well-dispersed Mo2N nanoparticles on nitrogen-doped carbon as a new and effective electrocatalyst for hydrogen evolution in alkaline electrolyte.

scholarly journals Use of Hybrid PEDOT:PSS/Metal Sulfide Quantum Dots for a Hole Injection Layer in Highly Efficient Green Phosphorescent Organic Light-Emitting Diodes

2021 ◽  
Vol 9 ◽  
Author(s):  
Wenqing Zhu ◽  
Kuangyu Ding ◽  
Chen Yi ◽  
Ruilin Chen ◽  
Bin Wei ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Efficiency ◽  
Light Emitting Diode ◽  
Metal Sulfide ◽  
Molybdenum Sulfide ◽  
Hole Injection ◽  
Light Emitting ◽  
Hole Injection Layer ◽  
Highly Efficient ◽  
Organic Light

In this study, we have synthesized the molybdenum sulfide quantum dots (MoS2 QDs) and zinc sulfide quantum dots (ZnS QDs) and demonstrated a highly efficient green phosphorescent organic light-emitting diode (OLED) with hybrid poly (3,4-ethylenedioxythiophene)/poly (styrenesulfonate) (PEDOT:PSS)/QDs hole injection layer (HIL). The electroluminescent properties of PEDOT:PSS and hybrid HIL based devices were explored. An optimized OLED based on the PEDOT:PSS/MoS2 QDs HIL exhibited maximum current efficiency (CE) of 72.7 cd A−1, which shows a 28.2% enhancement as compared to counterpart with single PEDOT:PSS HIL. The higher device performance of OLED with hybrid HIL can be attributed to the enhanced hole injection capacity and balanced charge carrier transportation in the OLED devices. The above analysis illustrates an alternative way to fabricate the high efficiency OLEDs with sulfide quantum dots as a HIL.

scholarly journals Promoting the Performance of Li–CO2 Batteries via Constructing Three-Dimensional Interconnected K+ Doped MnO2 Nanowires Networks

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhuolin Tang ◽  
Mengming Yuan ◽  
Huali Zhu ◽  
Guang Zeng ◽  
Jun Liu ◽  
...  
Keyword(s):  
Noble Metals ◽  
High Efficiency ◽  
Low Cost ◽  
Three Dimensional ◽  
High Energy ◽  
High Energy Density ◽  
Cycle Performance ◽  
Energy Storage And Conversion ◽  
Actual Application ◽  
Charge Process

Nowadays, Li–CO2 batteries have attracted enormous interests due to their high energy density for integrated energy storage and conversion devices, superiorities of capturing and converting CO2. Nevertheless, the actual application of Li–CO2 batteries is hindered attributed to excessive overpotential and poor lifespan. In the past decades, catalysts have been employed in the Li–CO2 batteries and been demonstrated to reduce the decomposition potential of the as-formed Li2CO3 during charge process with high efficiency. However, as a representative of promising catalysts, the high costs of noble metals limit the further development, which gives rise to the exploration of catalysts with high efficiency and low cost. In this work, we prepared a K+ doped MnO2 nanowires networks with three-dimensional interconnections (3D KMO NWs) catalyst through a simple hydrothermal method. The interconnected 3D nanowires network catalysts could accelerate the Li ions diffusion, CO2 transfer and the decomposition of discharge products Li2CO3. It is found that high content of K+ doping can promote the diffusion of ions, electrons and CO2 in the MnO2 air cathode, and promote the octahedral effect of MnO6, stabilize the structure of MnO2 hosts, and improve the catalytic activity of CO2. Therefore, it shows a high total discharge capacity of 9,043 mAh g−1, a low overpotential of 1.25 V, and a longer cycle performance.

Fe-Co-P multi-heterostructure arrays for efficient electrocatalytic water splitting

2021 ◽  
Author(s):  
Hanwen Xu ◽  
Jiawei Zhu ◽  
Pengyan Wang ◽  
Ding Chen ◽  
Chengtian Zhang ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Hydrogen Evolution ◽  
Water Splitting ◽  
Oxygen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Oxygen Evolution Reaction ◽  
Rational Design ◽  
Large Scale ◽  
High Efficiency ◽  
Bifunctional Catalysts

Rational design and construction of high-efficiency bifunctional catalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is crucial for large-scale hydrogen production by water splitting. Herein, by a...

MOF-derived hierarchical 3D bi-doped CoP nanoflower eletrocatalyst for hydrogen evolution reaction in both acidic and alkaline media

2020 ◽  
Vol 56 (56) ◽  
pp. 7702-7705 ◽  
Author(s):  
Lei Guo ◽  
Xue Bai ◽  
Hui Xue ◽  
Jing Sun ◽  
Tianshan Song ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Current Density ◽  
Alkaline Media ◽  
Alkaline Electrolyte ◽  
Acidic Electrolyte ◽  
Acidic And Alkaline Media ◽  
A Current

A 3D hierarchical Bi-doped CoP nanoflowers electrocatalyst is developed based on a MOF self-sacrifice strategy. The 3% Bi/CoP catalyst delivers a current density of 10 mA cm−2 at low overpotentials of 122 mV in alkaline electrolyte and 150 mV in acidic electrolyte.

scholarly journals Nitrogen Functionalization of CVD Grown Three-Dimensional Graphene Foam for Hydrogen Evolution Reactions in Alkaline Media

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4952
Author(s):  
Daniela Ion-Ebrașu ◽  
Radu Dorin Andrei ◽  
Stanică Enache ◽  
Simona Căprărescu ◽  
Constantin Cătălin Negrilă ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Photoelectron Spectroscopy ◽  
Hydrothermal Process ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Alkaline Media ◽  
Active Nitrogen ◽  
Graphene Foam ◽  
Graphene Layers ◽  
Nitrogen Doped

Three-dimensional graphene foam (3D-GrFoam) is a highly porous structure and sustained lattice formed by graphene layers with sp2 and sp3 hybridized carbon. In this work, chemical vapor deposition (CVD)—grown 3D-GrFoam was nitrogen-doped and platinum functionalized using hydrothermal treatment with different reducing agents (i.e., urea, hydrazine, ammonia, and dihydrogen hexachloroplatinate (IV) hydrate, respectively). X-ray photoelectron spectroscopy (XPS) survey showed that the most electrochemically active nitrogen-doped sample (GrFoam3N) contained 1.8 at % of N, and it exhibited a 172 mV dec−1 Tafel plot associated with the Volmer–Heyrovsky hydrogen evolution (HER) mechanism in 0.1 M KOH. By the hydrothermal process, 0.2 at % of platinum was anchored to the graphene foam surface, and the resultant sample of GrFoamPt yielded a value of 80 mV dec−1 Tafel associated with the Volmer–Tafel HER mechanism. Furthermore, Raman and infrared spectroscopy analysis, as well as scanning electron microscopy (SEM) were carried out to understand the structure of the samples.

scholarly journals Ru catalyst supported on nitrogen-doped nanotubes as high efficiency electrocatalysts for hydrogen evolution in alkaline media

RSC Advances ◽  
2020 ◽  
Vol 10 (38) ◽  
pp. 22297-22303
Author(s):  
Qinglei Liu ◽  
Lehao Yang ◽  
Peng Sun ◽  
Haigang Liu ◽  
Jiahua Zhao ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Hydrogen Evolution ◽  
Potential Application ◽  
High Efficiency ◽  
Alkaline Media ◽  
Ru Catalyst ◽  
Nitrogen Doped ◽  
Conversion System ◽  
Energy Conversion System ◽  
Increasing Demand

Due to the potential application in the future energy conversion system, there is an increasing demand for efficient, stable and cheap platinum-free catalysts for hydrogen evolution.

Tunable Linear Donor-π-Acceptor Conjugated Polymers with Vinylene Linkage for Visible-Light Driven Hydrogen Evolution

2021 ◽  
Author(s):  
Shitong Han ◽  
Tao Huang ◽  
Yi Pan ◽  
JiWu Zhao ◽  
Lin Huan ◽  
...  
Keyword(s):  
Visible Light ◽  
Conjugated Polymers ◽  
Hydrogen Evolution ◽  
Rational Design ◽  
High Efficiency ◽  
H2 Production ◽  
Design And Synthesis ◽  
Visible Light Driven

This work demonstrated the rational design and synthesis of the donor-π-acceptor (D-π-A) linear vinylene-linked polymers for visible-light driven H2 production with high-efficiency. Extending the in-plane conjugation, enhancing the electron push-pull...

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