Metal telluride-nitride electrocatalysts for sustainably overall seawater electrolysis

2021 ◽  
Author(s):  
Ruopeng Li ◽  
Yaqiang Li ◽  
Peixia Yang ◽  
Penghui Ren ◽  
Dan Wang ◽  
...  
Keyword(s):  
Active Sites ◽  
High Efficiency ◽  
Low Voltage ◽  
Low Cost ◽  
Intrinsic Activity ◽  
Iron Nitride ◽  
Electron Mass ◽  
Nickel Iron ◽  
Solar Powered ◽  
Seawater Electrolysis

Abstract High-efficiency alkaline seawater electrolysis is a promising strategy to promote the sustainability of wide-ranging hydrogen (H2) production, and the global goal of carbon neutrality. Searching for an ideal candidate with low cost and high electrocatalytic performance for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) is a major objective. Herein, we report delicate, heterostuctured NiTe-NiCoN and NiTe-NiFeN electrocatalysts constructed of nickel cobalt nitride and nickel iron nitride nanosheets uniformly anchored on NiTe nanorod arrays, respectively, which ensure outstanding HER and OER activity along with ultra-long-term stability. Impressively, the NiTe-NiCoN || NiTe-NiFeN couples in alkaline seawater solution delivered 500 mA cm−2 at a record low voltage of 1.84 V, and realized an industry-level performance via a solar-powered system and a wind-power system. Further comprehensive analysis has revealed that interface engineering strategy not only ensures that the surficial nitride exposes abundant active sites, but also induces electron modulation that optimizes the binding strength of absorption/desorption for the reaction intermediates to enhanced the the intrinsic activity, as well as facilitate faster electron-mass transfer. Notably, a high electric field intensity generated by the unique nanosheet-nanorod structure induces a local “hydroxide enrichment” environment that effectively promotes the OER kinetics, while inhibits the side effects of chlorine. This work shed lights on these novel heterostructured electrocatalysts with strong synergy, while demonstrating the key role of the unique nanostructures in high-efficiency seawater electrolysis.

Nanoboxes endow non-noble-metal-based electrocatalysts with high efficiency for overall water splitting

2021 ◽  
Author(s):  
Cheng Wang ◽  
Hongyuan Shang ◽  
Hui Xu ◽  
Yukou Du
Keyword(s):  
Water Splitting ◽  
Noble Metal ◽  
Active Sites ◽  
High Efficiency ◽  
Synergistic Effects ◽  
Electron Mass ◽  
Electronic Effects ◽  
Promising Candidate ◽  
Surface Active ◽  
Electrochemical Water Splitting

Non-noble-metal nanoboxes with abundant surface active sites, facilitated electron/mass transport, favorable synergistic effects and electronic effects, serving as promising candidate materials for boosting electrochemical water splitting.

scholarly journals High intrinsic activity of the oxygen evolution reaction in low-cost NiO nanowall electrocatalysts

2020 ◽  
Vol 1 (6) ◽  
pp. 1971-1979
Author(s):  
Salvatore Cosentino ◽  
Mario Urso ◽  
Giacomo Torrisi ◽  
Sergio Battiato ◽  
Francesco Priolo ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Thermal Annealing ◽  
Chemical Bath Deposition ◽  
Oxygen Evolution Reaction ◽  
High Efficiency ◽  
Low Cost ◽  
Intrinsic Activity

NiO nanowalls grown by low-cost chemical bath deposition and thermal annealing are a high-efficiency and sustainable electrocatalytst for OER.

scholarly journals A Comparative Analysis of Half-Bridge LLC Resonant Converters Using Si and SiC MOSFETs

2021 ◽  
Vol 12 (1) ◽  
pp. 43
Author(s):  
Hasaan Farooq ◽  
Hassan Abdullah Khalid ◽  
Waleed Ali ◽  
Ismail Shahid
Keyword(s):  
Silicon Carbide ◽  
Renewable Energy ◽  
High Frequency ◽  
High Efficiency ◽  
Low Voltage ◽  
Low Cost ◽  
Renewable Energy Sources ◽  
Input Voltage ◽  
Resonant Converters ◽  
Wide Range

With the expansion of renewable energy sources worldwide, the need for developing more economical and more efficient converters that can operate on a high frequency with minimal switching and conduction losses has been increased. In power electronic converters, achieving high efficiency is one of the most challenging targets to achieve. The utilization of wideband switches can achieve this goal but add additional cost to the system. LLC resonant converters are widely used in different applications of renewable energy systems, i.e., PV, wind, hydro and geothermal, etc. This type of converter has more benefits than the other converters such as high electrical isolation, high power density, low EMI, and high efficiency. In this paper, a comparison between silicon carbide (SiC) MOSFET and silicon (Si) MOSFET switches was made, by considering a 3KW half-bridge LLC converter with a wide range of input voltage. The switching losses and conduction losses were analyzed through mathematical calculations, and their authenticity was validated with the help of software simulations in PSIM. The results show that silicon carbide (SiC) MOSFETs can work more efficiently, as compared with silicon (Si) MOSFETs in high-frequency power applications. However, in low-voltage and low-power applications, Si MOSFETs are still preferable due to their low-cost advantage.

scholarly journals Design of Landsman Converter Fed BLDC Motor using IFOC and Back EMF Estimation Method

2020 ◽  
Vol 8 (5) ◽  
pp. 2958-2963
Keyword(s):  
High Efficiency ◽  
Low Voltage ◽  
Low Cost ◽  
Estimation Method ◽  
Torque Ripple ◽  
Bldc Motor ◽  
Brushless Dc ◽  
Low Voltage Operation ◽  
Indirect Field Oriented Control ◽  
Paper Sensor

In this paper, sensor-less control of Brushless DC (BLDC) motor drive fed from Landsman Converter (LC) powered from photovoltaic (PV) is designed to improve the performance of the motor. For obtaining the torque ripple minimization and accurate speed control using simplified Indirect Field Oriented Control (IFOC) is applied to the motor with Back-EMF estimation method. It is used for estimation of speed in sensor-less approach and implements to tracks the continuous changes of speed. This estimated speed is used to initiate the rotor position, and hall commutation signals predicted from the rotor angle. The performance of sensor less BLDC motor with low voltage operation which expresses high efficiency at low cost and reduction in torque ripple are verified using MATLAB/Simulink.

scholarly journals A High-Efficiency, Low-Cost Solution for On-Board Power Converters

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
V. Boscaino ◽  
G. Capponi
Keyword(s):  
Power Efficiency ◽  
High Efficiency ◽  
Low Voltage ◽  
Low Cost ◽  
Input Voltage ◽  
High Current ◽  
Forward Converter ◽  
System Cost ◽  
Zero Voltage Switching ◽  
Reset Voltage

Wide-input, low-voltage, and high-current applications are addressed. A single-ended isolated topology which improves the power efficiency, reduces both switching and conduction losses, and heavily lowers the system cost is presented. During each switching cycle, the transformer core reset is provided. The traditional tradeoff between the maximum allowable duty-cycle and the reset voltage is avoided and the off-voltage of active switches is clamped to the input voltage. Therefore, the system cost is heavily reduced and the converter is well suited for wide-input applications. Zero-voltage switching is achieved for active switches, and the power efficiency is greatly improved. In the output mesh, an inductor is included making the converter suitable for high-current, low-voltage applications. Since the active clamp forward converter is the closest competitor of the proposed converter, a comparison is provided as well. In this paper, the steady-state and small-signal analysis of the proposed converter is presented. Design examples are provided for further applications. Simulation and experimental results are shown to validate the great advantages brought by the proposed topology.

scholarly journals Atomically dispersed Ni in cadmium-zinc sulfide quantum dots for high-performance visible-light photocatalytic hydrogen production

2020 ◽  
Vol 6 (33) ◽  
pp. eaaz8447 ◽  
Author(s):  
D. W. Su ◽  
J. Ran ◽  
Z. W. Zhuang ◽  
C. Chen ◽  
S. Z. Qiao ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Zinc Sulfide ◽  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Surface Engineering ◽  
High Efficiency ◽  
Single Atom ◽  
Intrinsic Activity ◽  
Cadmium Zinc Sulfide ◽  
Cadmium Zinc

Catalysts with a single atom site allow highly tuning of the activity, stability, and reactivity of heterogeneous catalysts. Therefore, atomistic understanding of the pertinent mechanism is essential to simultaneously boost the intrinsic activity, site density, electron transport, and stability. Here, we report that atomically dispersed nickel (Ni) in zincblende cadmium–zinc sulfide quantum dots (ZCS QDs) delivers an efficient and durable photocatalytic performance for water splitting under sunlight. The finely tuned Ni atoms dispersed in ZCS QDs exhibit an ultrahigh photocatalytic H2 production activity of 18.87 mmol hour−1 g−1. It could be ascribed to the favorable surface engineering to achieve highly active sites of monovalent Ni(I) and the surface heterojunctions to reinforce the carrier separation owing to the suitable energy band structures, built-in electric field, and optimized surface H2 adsorption thermodynamics. This work demonstrates a synergistic regulation of the physicochemical properties of QDs for high-efficiency photocatalytic H2 production.

scholarly journals Three-Phase Heterojunction NiMo-Based Nano-Needle for Water Splitting at Industrial Alkaline Condition

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Guangfu Qian ◽  
Jinli Chen ◽  
Tianqi Yu ◽  
Jiacheng Liu ◽  
Lin Luo ◽  
...  
Keyword(s):  
Water Splitting ◽  
Active Sites ◽  
High Performance ◽  
Density Functional ◽  
High Efficiency ◽  
Density Functional Theory Calculations ◽  
Intrinsic Activity ◽  
Alkaline Condition ◽  
Rate Determining Step ◽  
Three Phase

AbstractConstructing heterojunction is an effective strategy to develop high-performance non-precious-metal-based catalysts for electrochemical water splitting (WS). Herein, we design and prepare an N-doped-carbon-encapsulated Ni/MoO2 nano-needle with three-phase heterojunction (Ni/MoO2@CN) for accelerating the WS under industrial alkaline condition. Density functional theory calculations reveal that the electrons are redistributed at the three-phase heterojunction interface, which optimizes the adsorption energy of H- and O-containing intermediates to obtain the best ΔGH* for hydrogen evolution reaction (HER) and decrease the ΔG value of rate-determining step for oxygen evolution reaction (OER), thus enhancing the HER/OER catalytic activity. Electrochemical results confirm that Ni/MoO2@CN exhibits good activity for HER (ƞ-10 = 33 mV, ƞ-1000 = 267 mV) and OER (ƞ10 = 250 mV, ƞ1000 = 420 mV). It shows a low potential of 1.86 V at 1000 mA cm−2 for WS in 6.0 M KOH solution at 60 °C and can steadily operate for 330 h. This good HER/OER performance can be attributed to the three-phase heterojunction with high intrinsic activity and the self-supporting nano-needle with more active sites, faster mass diffusion, and bubbles release. This work provides a unique idea for designing high efficiency catalytic materials for WS.

FeP3 monolayer as a high-efficiency catalyst for hydrogen evolution reaction

2019 ◽  
Vol 7 (44) ◽  
pp. 25665-25671 ◽  
Author(s):  
Shuang Zheng ◽  
Tong Yu ◽  
Jianyan Lin ◽  
Huan Lou ◽  
Haiyang Xu ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
High Efficiency ◽  
Low Cost ◽  
High Electrical Conductivity

An urgent and key problem in hydrogen evolution reaction (HER) is to prepare low-cost catalysts with activity comparable to that of platinum (Pt), an intrinsic large number of active sites, and high electrical conductivity.

Stabilizing Oxygen Intermediates on Redox-Flexible Active Sites in Multimetallic Ni-Fe-Al-Co Layered Double Hydroxide Anodes for Excellent Alkaline and Seawater Electrolysis

2021 ◽  
Author(s):  
Enhbayar Enhtuwshin ◽  
Kang Min Kim ◽  
Young-Kwang Kim ◽  
Sungwook Mhin ◽  
So Jung Kim ◽  
...  
Keyword(s):  
Water Splitting ◽  
Layered Double Hydroxide ◽  
Layered Double Hydroxides ◽  
Oxygen Evolution Reaction ◽  
Active Sites ◽  
Oxygen Intermediates ◽  
Nickel Iron ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Seawater Electrolysis

Development of an efficient and stable electrocatalyst for oxygen evolution reaction (OER) is crucial to make hydrogen generated via water splitting as a sustainable fuel. Nickel iron layered double hydroxides...

Research of Practical Solar Energy Intelligent Regulated Power Supply

2013 ◽  
Vol 385-386 ◽  
pp. 1189-1192
Author(s):  
Hong Li Cheng ◽  
Wei Zhang ◽  
Geng Chuan Zhang
Keyword(s):  
Pid Control ◽  
Output Voltage ◽  
High Efficiency ◽  
Abrupt Change ◽  
Low Voltage ◽  
Buck Converter ◽  
Fuzzy Pid ◽  
Fuzzy Pid Control ◽  
Circuit Structure ◽  
Solar Powered

A solar-powered fuzzy PID control based DC/DC series the LDO method is suggested to take advantage of the performance of the DC/DC converter high efficiency while reduce the output ripple and low voltage is continuously adjustable. Fuzzy PID control according to the error of sampling the output voltage and the desired output voltage, the DC/DC output and LDO output with constant pressure difference control. The circuit structure, the dynamic response of output voltage in the process of abrupt change of load and starting is analyzed. Parameter selection and design considerations are given. A BUCK converter is used as an example to show the design steps. Simulation study are made on the supply, the results of which show that method is feasible

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