Voltammetric and drift spectroscopy investigation in dithiophosphinate-chalcopyrite system

Guler, T
Hicyilmaz, C
Gokagac, G
Ekmekci, Z
The mechanism of dithiophosphinate (DTPI) adsorption on chalcopyrite was investigated by diffuse reflectance Fourier transformation (DRIFT) spectroscopy and by cyclic voltammetry (CV) at various pHs. CV experiments showed that the redox reactions occurred at a certain degree of irreversibility on the chalcopyrite surface in the absence of a collector due to preferential dissolution of iron ions in slightly acid solution and irreversible surface coverage by iron oxyhydroxides in neutral and alkaline solutions. In the presence of DTPI, CV experiments failed to identify the type of the adsorbed DTPI species and electrochemical processes occurring on chalcopyrite due to formation of an electrochemically passive surface layer preventing electron transfer. However, DRIFT spectroscopy tests showed this passive layer to be mainly CuDTPI + (DTPI)(2). Both CV and DRIFT spectroscopy established that the activity of collector species decreased with increasing pH due to formation of stable hydrophilic metal oxyhydroxides on the chalcopyrite surface.


Magnetically separable rhodium nanoparticles as catalysts for releasing hydrogen from the hydrolysis of ammonia borane
Tonbul, Yalcin; Akbayrak, Serdar; Özkar, Saim (Elsevier BV, 2019-10-01)
Magnetically separable catalysts attract considerable attention in catalysis due to their facile separation from the reaction medium. This propensity is crucial for efficient multiple use of precious noble metal nanoparticles in catalysis. In fact, the isolation of catalysts from the reaction medium by filtration and washing results usually in the loss of huge amount of activity in the subsequent run of catalysis. Although many transition metal nanoparticle catalysts have been reported for the H-2 generatio...
Optoelectrochemical properties of the copolymer of 2,5-di(4-methylthiophen-2-yl)-1-(4-nitrophenyl)-1H-pyrrole monomer with 3,4-ethylenedioxythiophene
AK, Metin; Tanyeli, Cihangir; Akhmedo, Dris M.; Toppare, Levent Kamil (Elsevier BV, 2008-04-30)
Copolymer of 2,5-di(4-methylthiophen-2-yl)-1-(4-nitrophenyl)-1H-pyrrole (MTNP) with 3,4-ethylene dioxythiophene (EDOT) was electro-chemically synthesized and characterized via cyclic voltammetry, Fourier Transform Infrared spectroscopy, Scanning Electron Microscopy, conductivity measurements. Spectroelectrochemical investigations showed that resulting copolymer film has distinct electrochromic properties. It has five different colors (dark purple, red, light grey, green, blue). At the neutral state m due to...
Nickel(0) nanoparticles supported on bare or coated cobalt ferrite as highly active, magnetically isolable and reusable catalyst for hydrolytic dehydrogenation of ammonia borane
Manna, Joydev; AKBAYRAK, SERDAR; Özkar, Saim (Elsevier BV, 2017-12-15)
Nickel(0) nanoparticles supported on cobalt ferrite (Ni-0/CoFe2O4), polydopamine coated cobalt ferrite (NP0/PDA-CoFe2O4) or silica coated cobalt ferrite (NP0/SiO2-CoFe2O4) are prepared and used as catalysts in hydrogen generation from the hydrolysis of ammonia borane at room temperature. Ni-0/CoFe2O4 (4.0% wt. Ni) shows the highest catalytic activity with a TOF value of 38.3 min(-1) in hydrogen generation from the hydrolysis of ammonia borane at 25.0 +/- 0.1 degrees C. However, the initial catalytic activit...
Intensity dependent time-resolved photoluminescence studies of GaN/AlGaN multiple quantum wells of varying well width on laterally overgrown a-plane and planar c-plane GaN
Garrett, GA; Shen, H; Wraback, M; İmer, Muhsine Bilge; Haskell, B; Speck, JS; Keller, S; Nakamura, S; DenBaars, SP (Wiley, 2005-04-01)
GaN/AlGaN multiple quantum wells (MQWs) of varying well width grown on planar c-plane GaN and a-plane GaN templates fabricated by lateral epitaxial overgrowth (LEO) have been studied by subpicosecond photoluminescence (PL) downconversion and time-correlated single photon counting as a function of pump intensity. Although slower room temperature decays at higher carrier density are observed in both a-plane LEO and c-plane MQWs with 3 nm well width, this behavior is attributed to suppression of electric field...
Refractive index, static dielectric constant, energy band gap and oscillator parameters of Ga2SeS single crystals
Qasrawi, A. F.; Hasanlı, Nızamı (Wiley, 2007-09-01)
The optical properties of Bridgman method grown Ga2SeS crystals have been investigated by means of room-temperature transmittance and reflectance spectral analysis. The optical data have revealed direct and indirect allowed transition band gaps of 2.49 and 2.10 eV, respectively. The room-temperature refractive index, which was calculated from the reflectance and transmittance data, allowed the identification of the dispersion and oscillator energies, static dielectric constant and static refractive index as...
Citation Formats
T. Guler, C. Hicyilmaz, G. Gokagac, and Z. Ekmekci, “Voltammetric and drift spectroscopy investigation in dithiophosphinate-chalcopyrite system,” JOURNAL OF COLLOID AND INTERFACE SCIENCE, pp. 46–54, 2004, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/67449.