Photoelectrochemical Characteristics of n-InSe Single Crystals

1995 ◽  
Vol 60 (12) ◽  
pp. 2039-2046
Author(s):  
Ioannis Poulios ◽  
Kostantinos Farmakis ◽  
Kostantinos Paraskevopoulos
Keyword(s):  
Aqueous Solutions ◽  
Single Crystals ◽  
Energy Gap ◽  
Flat Band ◽  
Flat Band Potential ◽  
Differential Capacity ◽  
Redox Systems ◽  
Donor Density ◽  
Presence And Absence

The photoelectrochemical behaviour of n-InSe single crystals in aqueous solutions has been studied in the presence and absence of several redox systems. Among them, Ce3+/4+ and KI/I2 yielded the highest photocurrents, photovoltages and show the highest stability. The semiconductor energy gap Eg = 1.2 eV, has been calculated from transmittance measurements. The flat band potential UFB = -0.40 V vs NHE and the donor density have been calculated from differential capacity measurements.

Effects of Al on the Flat Band Potential of Nanostructured TiO2 Electrodes

2013 ◽  
Vol 291-294 ◽  
pp. 2731-2733
Author(s):  
Shu Ming Yang ◽  
Guang Hui Zhu ◽  
Shu Pei Guo
Keyword(s):  
Energy Gap ◽  
Visible Region ◽  
Raw Material ◽  
Flat Band ◽  
Flat Band Potential ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
Al Doping ◽  
Doped Tio2 ◽  
X Ray

In this paper, Al(NO3)3•9H2O was used as raw material and the nanoparticles of Al-doped TiO2 were prepared by hydrothermal method. The nanoparticles and films were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Ultraviolet and Visible Spectroscopy (UV-Vis). The flat band potential (Efb) of nanostructured TiO2 and Al-doped TiO2 in acetone have been determined with spectroelectrochemistry measurement. The results show that Al doping decreases the energy gap and improves the absorption ability in visible region. On the other hand, Al doping TiO2 can effectively embarrass the crystal growth of TiO2. Specifically, the Efb of TiO2 and Al-doped TiO2 can be determined to be -0.6 V and -0.3V.

Constraints to the flat band potential of hematite photo-electrodes

2014 ◽  
Vol 16 (30) ◽  
pp. 16176-16186 ◽  
Author(s):  
A. Hankin ◽  
J. C. Alexander ◽  
G. H. Kelsall
Keyword(s):  
Aqueous Solutions ◽  
Flat Band ◽  
Flat Band Potential

Reasons are discussed for the widely disparate, reported flat band potentials for semiconducting hematite (photo-) electrodes in aqueous solutions.

scholarly journals Effects of In Situ Co or Ni Doping on the Photoelectrochemical Performance of Hematite Nanorod Arrays

2020 ◽  
Vol 10 (10) ◽  
pp. 3567
Author(s):  
Feng Cheng ◽  
Xiuwei Li
Keyword(s):  
Band Gap ◽  
Energy Gap ◽  
Saturated Calomel Electrode ◽  
Molar Ratio ◽  
Flat Band ◽  
Flat Band Potential ◽  
Nanorod Arrays ◽  
Ni Doping ◽  
Co Doped

Co-doped and Ni-doped hematite (α-Fe2O3) nanorod arrays were prepared on fluorine-doped tin oxide (FTO) conductive glass via aqueous chemical growth, in which the doping and the formation of nanorods occurred simultaneously (i.e., in situ doping). These samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet (UV)–visible spectrophotometry, linear sweep voltammetry and Mott–Schottky (M–S) measurement. Results showed that the introduction of 5% Co or Ni into α-Fe2O3 (the molar ratio of dopant to Fe is 1:20) did not change its crystal phase, morphology, energy gap and flat band potential. Both the undoped and the doped α-Fe2O3 showed a direct band gap of 2.24 eV, an indirect band gap of 1.85 eV, and a flat band potential of −0.22 V vs. saturated calomel electrode (SCE). At an applied potential of 0.2 V vs. SCE, the Co-doped and the Ni-doped α-Fe2O3 exhibited a photocurrent of 1.28 mA/cm2 and 0.79 mA/cm2, respectively, which were 2.1 times and 1.3 times that of the undoped α-Fe2O3. After the Co or Ni doping, the charge carrier concentration increased from 1.65 × 1025 m−3 to 3.74 × 1025 m−3 and 2.50 × 1025 m−3, respectively. Therefore, the increase in the photocurrent of the doped α-Fe2O3 was likely attributed to their enhanced conductivity.

Study of potential oscillations during reaction of an aluminium single crystal with an aqueous KOH solution

1990 ◽  
Vol 55 (2) ◽  
pp. 345-353 ◽  
Author(s):  
Ivan Halaša ◽  
Milica Miadoková
Keyword(s):  
Aqueous Solutions ◽  
Single Crystal ◽  
Single Crystals ◽  
Periodic Potential ◽  
Optimum Conditions ◽  
Potential Oscillations ◽  
Dilute Aqueous Solutions ◽  
Experimental Findings ◽  
Kinetics Of

The authors investigated periodic potential changes measured on oriented sections of Al single crystals during spontaneous dissolution in dilute aqueous solutions of KOH, with the aim to find optimum conditions for the formation of potential oscillations. It was found that this phenomenon is related with the kinetics of the reaction investigated, whose rate also changed periodically. The mechanism of the oscillations is discussed in view of the experimental findings.

Flat band potential of as-grown n-MoSe2 single crystal electrodes

1988 ◽  
Vol 110 (1) ◽  
pp. 293-299 ◽  
Author(s):  
R. Srivastava ◽  
V. M. Pathak ◽  
V. V. Rao
Keyword(s):  
Single Crystal ◽  
Flat Band ◽  
Flat Band Potential

Syntheses, Crystal Structures and Thermal Stability of Co(II) and Zn(II) Complexes with Ethyl Carbazate

2005 ◽  
Vol 60 (5) ◽  
pp. 505-510 ◽  
Author(s):  
Tong-Lai Zhang ◽  
Jiang-Chuang Song ◽  
Jian-Guo Zhang ◽  
Gui-Xia Ma ◽  
Kai-Bei Yu
Keyword(s):  
Thermal Stability ◽  
Aqueous Solutions ◽  
Diffraction Analysis ◽  
Single Crystals ◽  
Slow Evaporation ◽  
X Ray Diffraction ◽  
Element Analysis ◽  
Thermal Stabilities ◽  
X Ray ◽  
Thermal Stability Of

Cobalt(II) and zinc(II) complexes of ethyl carbazate (ECZ), [Co(ECZ)3](NO3)2 and [Zn(ECZ)3] (NO3)2, were synthesized. Single crystals of these two compounds were grown from aqueous solutions using a slow evaporation method. Their structures have been determined by X-ray diffraction analysis. Both of them are monoclinic with space group P21/n. The complexes are further characterized by element analysis and IR measurements. Their thermal stabilities are studied by using TG-DTG, DSC techniques. When heated to 350 °C, only metal oxide was left for both complexes.

scholarly journals Growth and Characterization of Epsomite Single Crystals Doped with KCl from low Temperature Aqueous Solutions

1970 ◽  
Vol 33 (1) ◽  
pp. 47-54 ◽  
Author(s):  
S Ferdous ◽  
J Podder
Keyword(s):  
Aqueous Solutions ◽  
Single Crystals ◽  
Optical Quality ◽  
Dielectric Studies ◽  
Slow Cooling ◽  
Large Size ◽  
Isothermal Evaporation ◽  
Academy Of Sciences

Highly transparent and well faceted large size epsomite single crystals have been grown in pure form and doped with KCl from aqueous solutions by slow cooling and isothermal evaporation method. The optical quality of the epsomite improves on doping by KCl. Mass growth rates were found to increase with doping of lower concentrations of KCl and then decreases with the higher concentration of KCl. KCl doped epsomite crystal reveals that structures are slightly distorted due to adsorption of Cl- ion into the crystal lattice. DC conductivity along the growth axis for all of the grown crystals increases with temperature in the range of 25 to 70ºC and also increases with the KCl concentration. Dielectric constant is found to be almost independent of frequency up to range of 106Hz. The dielectric studies show the suitability of these grown crystals for optoelectronic applications. DOI: 10.3329/jbas.v33i1.2949 Journal of Bangladesh Academy of Sciences, Vol. 33, No. 1, 47-54, 2009

Fermi level pinning or semiconductor electrodes in aqueous and non aqueous electrolytes: influence of the modification of the electrode surface

1989 ◽  
Vol 67 (3) ◽  
pp. 382-388 ◽  
Author(s):  
O. Savadogo
Keyword(s):  
Fermi Level ◽  
Acidic Medium ◽  
Open Circuit ◽  
Flat Band ◽  
Flat Band Potential ◽  
Fermi Level Pinning ◽  
Material Surfaces ◽  
Electrolyte Interface ◽  
Semiconductor Electrodes ◽  
Minority Carriers

Modification of several semiconductors material surfaces with H4SiW12O40•nH2O have been carried out to produce an increase in the open circuit photopotential at the semiconductor/electrolyte interface (Voc) without changing the flat-band potential. The augmentation of Voc is shown to be attributed to a decrease of the minority carriers recombination at the semiconductor/electrolyte interface along with the suppression of Fermi level pinning. The enhancement of Voc and the electrocatalytic activity of the hydrogen evolution reaction in acidic medium of the derivatized electrodes is attributed to the Fermi level unpinning. Keywords: photoelectrodes, photoelectrocatalysis, pinning, modification improvement.

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