1. Efficient Iron Phosphide Catalyst as a Counter Electrode in Dye-Sensitized Solar Cells : articleAbdullah Yildiz, Takwa Chouki, Aycan Atli, Moussab Harb, Sammy W Verbruggen, Rajeshreddy Ninakanti, Saim Emin, 2021, izvirni znanstveni članek Opis: Developing an efficient material as a counter electrode (CE) with excellent catalytic activity, intrinsic stability, and low cost is essential for the commercial application of dye-sensitized solar cells (DSSCs). Transition metal phosphides have been demonstrated as outstanding multifunctional catalysts in a broad range of energy conversion technologies. Here, we exploited different phases of iron phosphide as CEs in DSSCs with an I–/I3–-based electrolyte. Solvothermal synthesis using a triphenylphosphine precursor as a phosphorus source allows to grow a Fe2P phase at 300 °C and a FeP phase at 350 °C. The obtained iron phosphide catalysts were coated on fluorine-doped tin oxide substrates and heat-treated at 450 °C under an inert gas atmosphere. The solar-to-current conversion efficiency of the solar cells assembled with the Fe2P material reached 3.96 ± 0.06%, which is comparable to the device assembled with a platinum (Pt) CE. DFT calculations support the experimental observations and explain the fundamental origin behind the improved performance of Fe2P compared to FeP. These results indicate that the Fe2P catalyst exhibits excellent performance along with desired stability to be deployed as an efficient Pt-free alternative in DSSCs. Ključne besede: Iron phosphide, catalyst, counter electrode, dye-sensitized solar cell, solvothermal synthesis Objavljeno v RUNG: 06.02.2023; Ogledov: 1983; Prenosov: 0 Gradivo ima več datotek! Več... |
2. Tungsten carbide electrocatalysts prepared from metallic tungsten nanoparticles for efficient hydrogen evolutionSaim Emin, Cesur Altinkaya, Ali Semerci, Hasan Okuyucu, Abdullah Yildiz, Plamen Stefanov, 2018, izvirni znanstveni članek Ključne besede: Tungsten carbide, Colloid, Hydrogen evolution, Overpotential, Electrocatalyst Objavljeno v RUNG: 23.05.2018; Ogledov: 5558; Prenosov: 0 Gradivo ima več datotek! Več... |
3. Tungsten carbide thin films for electrochemical water splitting studiesSaim Emin, Cesur Altinkaya, Ali Semerci, Matjaž Valant, Hasan Okuyucu, Abdullah Yildiz, 2017, objavljeni povzetek znanstvenega prispevka na konferenci Opis: We used wet-chemistry techniques to prepare colloidal tungsten (W) nanoparticles (NPs). The synthesis of W NPs was conducted using the so called hot-matrix method in 1-octadecene [1]. The sizes of obtained W NPs are in the order of 2 - 5 nm. These W NPs are coated with hydrophobic molecules which allow their dispersion in organic solvents like choloroform (CHCl3). It was found that the colloidal stability of the dispersions is exceptionally high exceeding several years. The stability of W NPs which prevents coagulation allows the preparation of thin films with uniform thicknesses by spin-coating, inkjet-printing and spray coating.
We have prepared tungsten carbide (W2C, WC) thin films. The preparation of W2C and WC was achieved by spin-coating of pre-synthesized W NPs on graphite substrate and following heat treatment under Ar atmosphere at 1000 and 1450°C.
The obtained W2C and WC films were used both in electrochemical water splitting studies. We also made a composite W2C-Pt films where we used only 5 at.% of Pt. The W2C-Pt composite has shown similar performance as pure Pt-C for hydrogen (H2) evolution. In conclusion, we have developed a procedure for the synthesis of W NPs which can be applied for the preparation of tungsten carbides films and their use for electrochemical water splitting. Ključne besede: water splitting, nanoparticles, hot-matrix Objavljeno v RUNG: 09.10.2017; Ogledov: 7266; Prenosov: 0 Gradivo ima več datotek! Več... |