July 2024
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39 Reads
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5 Citations
Applied Catalysis B Environmental
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July 2024
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39 Reads
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5 Citations
Applied Catalysis B Environmental
June 2024
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34 Reads
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4 Citations
Catalysis Today
August 2023
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33 Reads
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6 Citations
ACS Applied Engineering Materials
April 2023
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37 Reads
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3 Citations
Applied Surface Science
February 2023
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47 Reads
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9 Citations
Results in Engineering
Nanorod-TiO2 electrodes were obtained by a hydrothermal method in the presence of different concentrations of sodium chloride. The addition of NaCl during the synthesis promoted the formation of thinner, well-crystallized nanorods growing along the [001] crystallographic direction, while still, the most intense reflection is related to (101). The optimal electrode demonstrated applied bias photon to current efficiency (ABPE) of 0.24% in solar seawater splitting, which is among the highest reported efficiencies for the pristine TiO2 nanorods. Noteworthy, the ABPE of the obtained electrodes stayed intact during variation of the solar irradiation in the range of 0.2–1 Sun. It was also demonstrated that the efficiency of nanorod-TiO2 electrodes is higher for seawater splitting (0.5 M NaCl) than for water photoelectrolysis in the presence of 0.5 M Na2SO4. This phenomenon is the result of chloride evolution reaction taking place in addition to water oxidation. A gradual decrease in efficiency resulting from the low mobility of holes was observed for all electrodes. This conclusion was confirmed by experiments with a hole-scavenger (improved performance of the cell), as well as surface photovoltage measurements and electrochemical impedance spectroscopy.
February 2023
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33 Reads
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2 Citations
Dyes and Pigments
January 2021
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39 Reads
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2 Citations
Thermodynamics and kinetics of primary photophysical and photochemical processes govern the overall photoactivity of photocatalytic and photoelectrocatalytic systems. A proper determination of redox potentials, Fermi levels, quasi-Fermi levels, distribution of electronic states and surface traps, as well as lifetimes of photogenerated charge carriers and rate constants, are of major importance in understanding and designing photoactive systems. In this review, experimental methods helpful in thermodynamic and kinetic studies are presented and discussed. Among commonly used techniques, like diffuse reflectance, impedance, and time-resolved spectroscopies, the readers are acquainted with other, less known methods.
April 2020
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70 Reads
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31 Citations
Applied Catalysis B Environmental
A visible light responsive heterojunction system composed of Fe2O3 nanorods (NF), reduced graphene oxide (rGO) and double oxide perovskites (LaSrFe2–nConO6, n = 1 (LSFC) and 0 (LSFF)) was rationally designed for an effective photoelectrochemical water splitting. The photoelectrodes were characterized in terms of structure, surface, physicochemical and functional properties with a focus on the electronic structure (e.g., the density of electronic states, band-edge, Fermi level positions), which was gauged from UPS, Kelvin probe (KP) and spectroelectrochemical (SE-DRS) measurements. The KP measurements not only revealed the successful and efficient contact of the materials with different work functions but also showed the drift direction of photogenerated charges. In the studied systems, the transparent, thin layer of rGO facilitates the hole transfer from NF (photoabsorber) to perovskites (electrocatalyst). The hydrogen conversion efficiency under visible and solar simulated irradiation for [email protected]@LSFF reached remarkable values of 3.61% and 1.13% (STH), respectively.
September 2019
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19 Reads
September 2019
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18 Reads
In the energy storage context, metal ion batteries such as Li, Na, and K are governing the market. However, their activity significantly relied on anode materials. Mostly, the charging of these batteries occurs by produced electricity from environmentally hazardous processes [1]. In a totally different approach, light can be utilized to accelerate the charge/discharge process through the photoanode material. In order to reach such a goal, perovskite type oxide, as an important class of materials with suitable chemical and physical properties such as high ionic/electric conductivity, enhanced catalytic/photocatalytic activity and photoelectrochemical durability, is a favorable candidate for Li-O2 batteries. Herein, three-dimensionally ordered mesoporous (3dom) La0.8Ba0.2Co1-xFex (x = 0, 0.2 and 0.4) perovskites (Fig. 1a) decorated with selenium are prepared and employed as a photoanode. The 3dom structure facilitates the access of the reactant to the inner areas of the photocatalyst, which can be resulted in a higher efficiency compared to the nanoparticles. Following, the synthesized materials were investigated as photoactive electrodes using electrochemical techniques such as impedance electrochemical spectroscopy (EIS), cyclic voltammetry (CV) and charge/discharge in 0.5 M Na2SO4. Both CV and charge/discharge techniques showed an acceleration in the charging process once the electrodes were exposed to solar light. However, the discharge process was starched in the presence of light. Also, the EIS technique was used to study electrochemical responses in the presence and absence of light, as shown in Figure 1. The charge resistance of all prepared electrodes was reduced upon illumination. While, 3dom-La0.8Ba0.2Co0.6Fe0.4O3 (3dom-LB82CF64) demonstrated the highest activity.
... Therefore, the first idea in designing a new perovskite catalyst can start from the micro-morphology, synthesizing special spatial structures to directly increase the effective contact between active sites and reactants. Three-dimensional ordered macroporous (3DOM) structures, [11][12][13][14][15] with their larger pore diameters, allow soot to penetrate deep into the catalyst interior through gas mass transfer, thus efficiently utilizing the catalyst's active sites. [16,17] In addition, the rich active sites on the porous structure surface can significantly improve the catalyst's ability to adsorb and activate gas molecules (O 2 , NO x ), and the activation of gas molecules into highly active intermediates will help the occurrence of low-temperature deep oxidation reactions of soot particles. ...
July 2024
Applied Catalysis B Environmental
... The development of photocatalysts has made great strides in the past few decades [1][2][3][4][5][6][7][8]. Since 1972, TiO 2 has been used as a photocatalyst for the first time. ...
June 2024
Catalysis Today
... Moreover, an increase in the Cu concentration results in an increase in the Co 3+ ionic state, which can facilitate the formation of higher oxidation states, such as Co 4+ , which are believed to be the active species in the OER. The presence of Co 3+ in the catalyst structure leads to the formation of oxyl radicals, which are crucial for the OER mechanism [31][32][33]. However, an increase in the Cu concentration can cause serious agglomeration, which results in smaller electrochemically active surface areas, indicating the availability of a lower number of active sites for the OER. ...
August 2023
ACS Applied Engineering Materials
... Given the redox properties of the adsorbed (metallo)porphyrins and P25, the observed visible light-induced photocurrents may be due to electron transfer from the excited dyes to the TiO 2 conduction band. Tabari et al. recorded the generation of photocurrent when surface-modified TiO 2 remained unchanged under different polarization conditions, whether negative or positive ones [68]. Upon UV irradiation in the studied potential range, pristine TiO 2 generates anodic photocurrents. ...
February 2023
Dyes and Pigments
... Consequently, maximum ABPE values were shifted towards higher potentials > 900 mV, and, thus, they were slightly lower. Similar behavior was also found for nanorod-TiO 2 electrodes (measurements performed in 0.5M of NaCl and 0.5M Na 2 SO 4 ) [39], suggesting that the ClER (and possibly other reactions involving Cl-species) is more efficient than the OER at low overpotentials (<1000 mV), independent of the type of photoanode. photocurrent for individual electrodes and all-together connected electrically in parallel (bold line). ...
February 2023
Results in Engineering
... The bandgap engineering via introducing defects in the system along with the generation of new states whether occupied or empty within the valence band (VB) and conduction band (CB) is an efficient route to extend the light absorption range of the photocatalyst. At the same time, heterojunction design has been used to increase the cross-section of the light absorption, which can be divided into three categories: type I, type II, and type III [21][22][23]. Among all mentioned ways of engineering the bandgap, surface modification employing organic molecules (dyes) is straightforward and efficient. ...
January 2021
... The synthesis of double perovskite/rGO composite involved wet-chemical mixing of as-synthesized double perovskite oxide with graphene oxide (GO), followed by reduction of the GO into rGO via hydrothermal/solvothermal process. The resulting composite material consisted of the rGO dispersed throughout a matrix of double perovskite oxide which provided a highly conductive network for electron transport and ion diffusion [33][34][35][36][37][38][39][40][41][42]. The energy storage potential of the LMFO electrode and its composite have comprehensively been examined to illustrate their performance in supercapacitors. ...
April 2020
Applied Catalysis B Environmental
... Microwave-prepared BiFeO 3 and LaFeO 3 were examined for their photoelectrochemical properties. LaFeO 3 showed stronger water splitting than BiFeO 3 because of the Jahn-Teller distortion, which leads to charge separation [64]. Kim and his coworkers investigated the Fe doping in Co-based Perovskite oxide and explored its catalytic activity towards oxygen evolution reaction in alkaline media. ...
December 2018
Applied Surface Science
... Solar energy harvesting and utilization have paramount importance in the sustainable development and replacement of fossil fuels [1][2][3][4]. More importantly, the cost-effective and environmentally benign methods are well-appreciated to be employed in solar energy harvesting [5][6][7]. ...
March 2018
Journal of Alloys and Compounds
... Besides the methods mentioned above, Ball milling is also a simple physical process that can reduce the particle size of conventionally synthesized perovskites to the nanometer scale. However, this method often leads to high power consumption and typically results in perovskite nanomaterials with irregular shapes, contaminants, or amorphous components [70,110] In addition, researchers have successfully fabricated perovskite nanostructures using various other methods, including combustion synthesis [111,112], microwave-assisted method [113], pulsed laser deposition [114,115], chemical vapour deposition [116], and others [117][118][119]. The comparison of advantages and disadvantages of synthesis methods for perovskite oxides is presented in Table 1. ...
August 2017
Ceramics International