scholarly journals Metal doped layered MgB2 nanoparticles as novel electrocatalysts for water splitting

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ebrahim Sadeghi ◽  
Naeimeh Sadat Peighambardoust ◽  
Masoumeh Khatamian ◽  
Ugur Unal ◽  
Umut Aydemir

AbstractGrowing environmental problems along with the galloping rate of population growth have raised an unprecedented challenge to look for an ever-lasting alternative source of energy for fossil fuels. The eternal quest for sustainable energy production strategies has culminated in the electrocatalytic water splitting process integrated with renewable energy resources. The successful accomplishment of this process is thoroughly subject to competent, earth-abundant, and low-cost electrocatalysts to drive the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), preferably, in the same electrolyte. The present contribution has been dedicated to studying the synthesis, characterization, and electrochemical properties of newfangled electrocatalysts with the formal composition of Mg1−xTMxB2 (x = 0.025, 0.05, and 0.1; TM (transition metal) = Fe and Co) primarily in HER as well as OER under 1 M KOH medium. The electrochemical tests revealed that among all the metal-doped MgB2 catalysts, Mg0.95Co0.05B2 has the best HER performance showing an overpotential of 470 mV at − 10 mA cm−2 and a Tafel slope of 80 mV dec−1 on account of its high purity and fast electron transport. Further investigation shed some light on the fact that Fe concentration and overpotential for HER have adverse relation meaning that the highest amount of Fe doping (x = 0.1) displayed the lowest overpotential. This contribution introduces not only highly competent electrocatalysts composed of low-cost precursors for the water-splitting process but also a facile scalable method for the assembly of highly porous electrodes paving the way for further stunning developments in the field.

2020 ◽  
Author(s):  
Ebrahim Sadeghi ◽  
Naeimeh Peighambardoust ◽  
Masoumeh Khatamian ◽  
Ugur Unal ◽  
Umut Aydemir

Abstract Growing environmental problems along with the galloping rate of population growth have raised an unprecedented challenge to look for an ever-lasting alternative source of energy for fossil fuels. The eternal quest for sustainable energy production strategies has culminated in the electrocatalytic water splitting process integrated with renewable energy resources. The successful accomplishment of this process is thoroughly subject to highly efficient, earth-abundant, and cost-effective electrocatalysts to drive the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), preferably, in the same electrolyte. The present contribution has been dedicated to studying the synthesis, characterization, and electrochemical properties of newfangled electrocatalysts with the formal composition of Mg1-xTmxB2 (x = 0.025, 0.05, and 0.1; Tm (transition metal) = Fe and Co) primarily in HER as well as OER under 1 M KOH medium. The electrochemical tests revealed that among all the metal-doped MgB2 catalysts, Mg0.95Co0.05B2 has the best HER performance showing an overpotential of 470 mV at -10 mA cm-2 and a Tafel slope of 80 mV dec-1 on account of its high purity and fast electron transport. Further investigation shed some light on the fact that Fe concentration and overpotential for HER have adverse relation meaning that the highest amount of Fe doping (x = 0.1) displayed the lowest overpotential. This contribution introduces not only highly competent electrocatalysts composed of low-cost precursors for the water-splitting process but also a facile scalable method for the assembly of highly porous electrodes paving the way for further stunning developments in the field.


Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2839
Author(s):  
Mirza Imran Tariq ◽  
Majad Mansoor ◽  
Adeel Feroz Mirza ◽  
Nouman Mujeeb Khan ◽  
Muhammad Hamza Zafar ◽  
...  

The need for renewable energy resources is ever-increasing due to the concern for environmental issues associated with fossil fuels. Low-cost high-power-density manufacturing techniques for the thermoelectric generators (TEG) have added to the technoeconomic feasibility of the TEG systems as an effective power generation system in heat recovery, cooling, electricity, and engine-efficiency applications. The environment-dependent factors such as the nonuniform distribution of heat, damage to the heat-transfer coating between sinks and sources, and mechanical faults create nonuniform current generation and impedance mismatch causing power loss. As a solution to this nonlinear multisolution problem, an improved MPPT control is presented, which utilizes the improvised barnacle mating optimization (BMO). The case studies are formulated to gauge the performance of the proposed BMP MPPT control under nonuniform temperature distribution. The results are compared to the grey wolf optimization (GWO), particle swarm optimization (PSO), and cuckoo search (CS) algorithm. Faster global maximum power point tracking (GMPP) within 381 ms, higher power tracking efficiency of up to 99.93%, and least oscillation ≈0.8 W are achieved by the proposed BMO with the highest energy harvest on average. The statistical analysis further solidifies the better performance of the proposed controller with the least root mean square error (RMSE), RE, and highest SR.


Author(s):  
Sohel Shaikh

There has been a recent push to replace the burning of fossil fuels with biofuel. The replacement of this non-renewable energy resources with biological waste lowers the overall pollution of the world. The waste biomass similar to dry leaves, sawdust, rice husk, coffee husk etc. are gathered and compressed into the briquettes, these briquettes can also transport and used as fuel to generate heat and energy. It is a time to take initiative to turn Biomass into a source of energy. Hence here we are taking responsibility in converting agricultural and forestry wastes into useful biomass briquettes, which can also be used as a substitute for Coal and other non-renewable resources. Biomass briquettes are a biofuel substitute or replacement to a coal and charcoal. Biomass briquettes can be manufactured by using agricultural and forestry waste. The low-density biomass Is converted into high density biomass briquettes with the help of a briquetting machine that Uses binder or without binder i.e., binder less technique, as there is no any type of chemical is used so it is 100% natural. The mostly used raw material for biomass briquettes, Mustard Stalks, Sawdust, Groundnut Shell, Coffee Husk, Coir Pitch, Jute Sticks, Sugarcane Bagasse, Rice Husk, Cotton Stalks, Caster Seed Shells / Stalk, Wood Chips, Paddy straw, Tobacco Waste, Tea Waste, maize stalks, bajra Cobs, Arhar stalks, Bamboo Dust, Wheat Straw, Sunflower Stalk, Palm Husk, Soya bean Husk, Veneer Residues, Barks & Straws, Leaf’s, Pine Niddle, Seeds Cases etc. are used. Biomass Briquette are largely used for any type of thermal application, like steam generation in Boilers, in furnace & foundries (It can be used for metal heating & melting where melting point Is less than 1000d/cel.), for heating purpose (Residential & Commercial Heating in winter, Heating in Cold areas and Hotels, Canteens, Cafeterias and house hold kitchen appliances, restaurants etc.), There are several machines available in market but those machines are bulky and are costly, hence here we have developed a portable, low-cost briquetting machine, which makes use of simple mechanism to convert the biological waste into useful briquettes. Any waste or any proportion of Agri waste can be used but with proper binding agent. Some raw materials doesn’t require any binding material high pressure compression is used. The paper presents the results of a project focused on the development of briquettes from the sawdust (Waste Wood) resulting from the primary waste from timber companies. This sawdust currently lacks a useful purpose, and its indiscriminate burning generates CO and CO2 emissions which are harmful to nature. Sawmill Agri waste is a huge problem specially in urban cities. These wastes are burnt openly which is causing environmental pollution and also becomes reason for human health care.


2018 ◽  
Vol 877 ◽  
pp. 409-413 ◽  
Author(s):  
Dhandapani Sathish ◽  
R. Thirunavukkarasu ◽  
S. Jegadeeswaran ◽  
S. Periyasamy

On the increase of energy needs and rising environmental concern forces the use of renewable and to search the alternative source of energy for the polluting fossil fuels. The best alternative energy is solar which is being emitted by the sun and is collected and is stored in various thermal storage medium. Solar pond is one of the best ways to collect solar energy in that shallow solar pond is one of its type. From the name it implies the pond depth is small so the solar pond can be fabricated in a simple manner with very low cost covering large area. Previous research they have used baffle plates to find out the thermal performance, but this research brings out using CuO nano particles and has been examined experimentally. The shallow solar pond is built with a surface area of 1.7m2 with a depth of 0.5m. The experiment has been carried out during the month of April of 2016 under the climatic conditions of pachapalayam [Latitude 10.950N, Longitude 76.890E]. It was examined for the six successive sunny days and its temperature of lower convective zone varies from 1.3°C to 9.2°C, with the maximum rise in temperature is obtained when adding 0.8% concentration of nano particles.


Author(s):  
H. Kaneko ◽  
Y. Naganuma ◽  
S. Taku ◽  
K. Ouchi ◽  
N. Hasegawa ◽  
...  

Solar H2 production by the two-step water splitting process with thermochemical reaction has been proposed to convert solar energy into chemical energy. We succeeded in repeating the cyclic two-step water splitting process composed of the O2-releasing and H2-generation reactions with metal (Fe, Ni) doped ceria. The metal doped ceria with low content of metal ion (Fe3+, Ni2+) formed a solid solution with fluorite-type structure between ceria (CeO2) and metal oxide (Fe2O3, NiO). The empirical formula of the solid solution was Ce1-αMαO2−δ (M = Fe, Ni), and it was assumed that the high reactivity on the two-step water splitting process was due to an oxygen deficiency in the solid solution. The metal doped ceria with different Ce:M mole ratio (Ce:M = 0.97:0.03–0.7:0.3) was prepared through the combustion method. The two-step water-splitting process with metal doped ceria proceeded at 1673K for the O2-releasing reaction and at 1273K for the H2-generation reaction by irradiation of an infrared imaging lamp for a solar simulator. The amounts of H2 gas evolved in the H2-generation reaction with Fe-doped ceria and Ni-doped ceria with different Ce:M (M = Fe, Ni) mole ratio were 0.97–1.8 and 1.7–2.5 cm3/g, respectively, and the evolved H2/O2 ratios were approximately equaled to 2 of the stoichiometric value. The amounts of H2 and O2 gases evolved in the two-step water splitting process varied with the Ce:M mole ratio in the metal doped ceria. It was suggested that the O2-releasing and H2-generation reactions with metal doped ceria was repeated with the reduction and oxidation of Ce4+-Ce3+ enhanced by the presence of Fe or Ni ions. Furthermore, the O2-releasing reaction with Ni-doped ceria proceeded under a high O2 partial pressure atmosphere (pO2 = 0.05 atm) and at the temperature of 1773K. The progress of the O2-releasing reaction under a high pO2 indicates that metal doped ceria can be applicable for the rotary-type solar reactor developed by Tokyo Tech group for solar H2 production.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dingwang Huang ◽  
Lintao Li ◽  
Kang Wang ◽  
Yan Li ◽  
Kuang Feng ◽  
...  

AbstractA highly efficient, low-cost and environmentally friendly photocathode with long-term stability is the goal of practical solar hydrogen evolution applications. Here, we found that the Cu3BiS3 film-based photocathode meets the abovementioned requirements. The Cu3BiS3-based photocathode presents a remarkable onset potential over 0.9 VRHE with excellent photoelectrochemical current densities (~7 mA/cm2 under 0 VRHE) and appreciable 10-hour long-term stability in neutral water solutions. This high onset potential of the Cu3BiS3-based photocathode directly results in a good unbiased operating photocurrent of ~1.6 mA/cm2 assisted by the BiVO4 photoanode. A tandem device of Cu3BiS3-BiVO4 with an unbiased solar-to-hydrogen conversion efficiency of 2.04% is presented. This tandem device also presents high stability over 20 hours. Ultimately, a 5 × 5 cm2 large Cu3BiS3-BiVO4 tandem device module is fabricated for standalone overall solar water splitting with a long-term stability of 60 hours.


Author(s):  
Xiao Tan ◽  
Xin Liu ◽  
Yingying Si ◽  
Zunhang Lv ◽  
Zihan Li ◽  
...  

It is very important to design and prepare low-cost and efficiency electrocatalysts for water splitting in alkaline solution. In this works, Ni-Fe-P and Ni-Fe-P-FeMnO3 electrocatalysts are developed using facile electrodeposition...


2021 ◽  
Author(s):  
Harsha Bantawal ◽  
Sandhya U. Shenoy ◽  
Denthaje Krishna Bhat

CaTiO3 has attracted enormous interest in the field of photocatalytic dye degradation and water splitting owing to its low cost, excellent physicochemical stability and structural tunability. Herein, we have developed...


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shan Wang ◽  
Aolin Lu ◽  
Chuan-Jian Zhong

AbstractAs a promising substitute for fossil fuels, hydrogen has emerged as a clean and renewable energy. A key challenge is the efficient production of hydrogen to meet the commercial-scale demand of hydrogen. Water splitting electrolysis is a promising pathway to achieve the efficient hydrogen production in terms of energy conversion and storage in which catalysis or electrocatalysis plays a critical role. The development of active, stable, and low-cost catalysts or electrocatalysts is an essential prerequisite for achieving the desired electrocatalytic hydrogen production from water splitting for practical use, which constitutes the central focus of this review. It will start with an introduction of the water splitting performance evaluation of various electrocatalysts in terms of activity, stability, and efficiency. This will be followed by outlining current knowledge on the two half-cell reactions, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), in terms of reaction mechanisms in alkaline and acidic media. Recent advances in the design and preparation of nanostructured noble-metal and non-noble metal-based electrocatalysts will be discussed. New strategies and insights in exploring the synergistic structure, morphology, composition, and active sites of the nanostructured electrocatalysts for increasing the electrocatalytic activity and stability in HER and OER will be highlighted. Finally, future challenges and perspectives in the design of active and robust electrocatalysts for HER and OER towards efficient production of hydrogen from water splitting electrolysis will also be outlined.


Author(s):  
Yuting Luo ◽  
Zhiyuan Zhang ◽  
Fengning Yang ◽  
Jiong Li ◽  
Zhibo Liu ◽  
...  

Large-scale production of green hydrogen by electrochemical water splitting is considered as a promising technology to address critical energy challenges caused by the extensive use of fossil fuels. Although nonprecious...


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