Molybdenum diselenide (MoSe2) is an emerging alternative to platinum-group-metal electrocatalysts for the hydrogen evolution reaction (HER). Herein, the chemical vapor deposition (CVD) approach was demonstrated to be a successful route to grow MoSe2 thin films using colloidal molybdenum nanoparticles (Mo NPs). The synthesis of Mo NPs was achieved using a wet-chemical method. After spin-coating of Mo NPs onto graphite substrates, heat treatments in the presence of selenium vapors at several temperatures (?750 °C) were carried out. Electrocatalytic activities of the obtained MoSe2 films were evaluated for HER using linear sweep voltammetry (LSV). The best performing MoSe2 film (800°C) showed an overpotential of 218 mV at 10 mA cm-2 in 0.5 M sulfuric acid (H2SO4). In addition, electrochemical impedance spectroscopy (EIS) was used to access the charge-transfer resistance (Rct) of the MoSe2 films. The colloidal approach combined with CVD is a promising route to produce carbon supported MoSe2 electrocatalyst for HER.
COBISS.SI-ID: 47257603
In this paper, we present a solvothermal synthesis of iron phosphide electrocatalysts using a triphenylphosphine (TPP) precursor. The synthetic protocol generates Fe2P phase at 300°C and FeP phase at 350°C. To enhance the catalytic activities of obtained iron phosphide particles heat-treatments were carried out at elevated temperatures. Annealing at 500°C under reductive atmosphere induced structural changes in the samples: (i) Fe2P provided a pure Fe3P phase (Fe3P-500°C) and (ii) FeP transformed into a mixture of iron phosphide phases (Fe2P/FeP-500°C). Pure Fe2P films was prepared under argon atmosphere at 450°C (Fe2P-450°C). The electrocatalytic activities of heat-treated Fe2P-450°C, Fe3P-500°C, and Fe2P/FeP-500°C catalysts were studied for hydrogen evolution reaction (HER) in 0.5 M H2SO4. The HER activities of the iron phosphide catalyst were found to be phase dependent. The lowest electrode potential of 110 mV vs. a reversible hydrogen electrode (RHE) at 10 mA cm-2 was achieved with Fe2P/FeP-500°C catalyst.
COBISS.SI-ID: 22969603
A novel method was developed for the preparation of porous hematite (?-Fe2O3) thin films. First, a solution containing iron precursor was spin-coated on fluorine-doped tin oxide substrate and later short heat-treated at 750o C. The prepared ?-Fe2O3 thin films were applied as dual-function catalyst in photoelectrochemical (PEC) water oxidation and textile dye degradation studies. For the first time, ?-Fe2O3 thin films were used in efficient PEC degradation of a textile dye (Basic Blue 41 ? B41) using in-situ generated reactive chlorine species. In comparison with photocatalytic and electrocatalytic approaches, the PEC technique allows faster degradation of B41 dye at an applied bias potential of 1.5 V versus reversible hydrogen electrode and under visible light illumination. In the presence of Cl? using the PEC approach the degradation of B41 reaches 99.8 %. High-performance liquid chromatography coupled with UV-VIS system confirmed the degradation of B41 dye using PEC. Gas-chromatography coupled to mass spectrometry was used to study the by-products obtained during PEC degradation. Chemical oxygen demand analyses confirmed that the mineralization level of B41 is in the order of 68%. The ?-Fe2O3 films developed in this study give a higher level of PEC degradation efficiency compared to other iron oxide-based systems.
COBISS.SI-ID: 62466051
A solvothermal synthesis of iron phosphide electrocatalysts using triphenylphosphine (TPP) as phosphorus precursor is presented. The synthetic protocol generates Fe2P/FeP phase at 350°C. After deposition of the catalyst onto graphite substrate heat-treatment at higher temperature was carried out. Annealing at 500°C under reductive atmosphere induced structural changes in the Fe2P/FeP samples which yielded a pure Fe2P phase. The electrocatalytic activity of the Fe2P catalyst was studied for hydrogen evolution reaction (HER) in 0.5 M H2SO4. The recorded overpotential for HER was about 130 mV vs. a reversible hydrogen electrode (RHE) at 10 mA cm-2.
COBISS.SI-ID: 62474499