Cuprous oxide layers were obtained on a conductive glass substrate via room-temperature electrochemical deposition from the electrolyte containing 0.4 M CuSO4, 3 M lactic acid (pH = 12) at −0.5 V vs. ...SCE for various durations (from 0.25 to 3 h). Physicochemical properties of as-received FTO/Cu2O materials were characterized using SEM, PXRD, and UV–Vis DRS. The photoelectrochemical (PEC) properties of the obtained electrodes were evaluated in detail by analyzing the influence of the energy of monochromatic radiation, and the applied polarization on the resulting photocurrent transients. It was found that Cu2O crystals are getting bigger and sharper with prolonged electrosynthesis duration and a slight decrease in the band gap energy from 2.4 to 2.1 eV with increasing deposition duration was observed. Moreover, this trend was also reflected in PEC properties of resulted material, higher photocurrents were generated by the material deposited for 3 h. More importantly, this PEC response was enhanced by low-temperature (100 °C, 200 °C) annealing. Thermal treatment at 100 °C led to a noticeable improvement in the photoactivity of the samples. Further increasing post-treatment temperature to 200 °C resulted in a further six-fold increase in photocurrents. Finally, the calculated values of accumulated and dissipated charges indicated significantly lower surface recombination after thermal treatment.
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•Room-temperature electrodeposition of Cu2O on FTO-coated glass was studied.•The effect of synthesis time on morphology and structure was studied.•Extended deposition improves the photocurrent generated by the Cu2O/FTO electrodes.•Low-temperature annealing improves the PEC properties of the obtained materials.•Significantly lower surface recombination was observed after thermal treatment.
•MoO3 film is synthesized on carbon cloth through an electrodeposition process.•The electrochemical behaviors of as-made electrode are systematically exploded.•The ASSCs was assembled with MoO3 as ...both cathode and anode.•The 2.0 V ASSCs device shows an energy density of 78 Wh kg−1 at 1 kW kg−1.
Herein, a MoO3 film is directly synthesized on carbon cloth through a simple electrodeposition procedure with an annealing treatment. The clingy MoO3 film on carbon cloth fibers can speedily transfer electrons by virtue of the superior electrical conductivity of carbon cloth, while the outspread MoO3 film in the gap between the adjacent carbon cloth fibers can provide abundant channels for the diffusion of Li+. The electrochemical properties of the as-fabricated MoO3 electrode working as the cathode and anode materials are systematically studied, respectively. The specific capacitances of the MoO3 electrode within the potential ranges of 0–1.0 V and of −1.0 to 0 V are 603 and 835 F g−1 at 1 A g−1, respectively. The CV kinetic analysis reveals the surface capacitance-dominated charge storage mechanism for the MoO3 electrode under different potential windows. Moreover, the energy density of the as-assembled 2.0 V MoO3//MoO3 aqueous symmetric supercapacitor device can reach up to 78 Wh kg−1 at 1 kW kg−1. Notably, this device exhibits a brilliant lifespan with 98% storage retention after 8000 CV scans at 150 mV s−1. The ease of preparation and outstanding energy storage capability make this newly-assembled aqueous symmetric supercapacitor a highly potential candidate for practical applications.
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•Indium was deposited from deep eutectic solvents on copper and carbonaceous substrates.•Indium coatings were used as catalysts for the electrochemical CO2 reduction.•The indium ...coatings were stable after two-hour CO2 electrolysis.•The main product of the electrochemical CO2 reduction was formate.•The use of gas diffusion electrodes improved the formation rate of formate.
The electrochemical conversion of CO2 to high-value molecules is an elegant alternative for combining CO2 utilization with renewable energy conversion and storage. Herein we report the preparation and characterization of indium catalysts for the electrochemical CO2 reduction to formate. Indium coatings were prepared by electrodeposition from a deep eutectic solvent (DES) comprising 1:2 M choline chloride and ethylene glycol (12CE). The electrochemical behavior of indium chloride in this DES was investigated by cyclic voltammetry (CV) on copper, glassy carbon (GC) and platinum electrodes. The effect of InCl3 concentration, electrolyte temperature and deposition method on the phase and morphology of the coatings were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Indium deposits on copper and carbon were deployed as catalysts for the CO2 electrolysis in aqueous media. Chemical analysis by HPLC, GC, and NMR revealed an optimum efficiency toward formate at −1.9 V vs. Ag/AgCl. Indium coatings prepared by potentiostatic deposition showed faradaic efficiencies (FE) up to 72.5%. Gas diffusion electrodes (GDE) coated with indium led to formate concentrations up to 76 mM and formation rates of 0.183 mmol cm−2 h−1, which was considerably superior to indium coatings on planar electrodes.
The primary challenge of developing clean energy conversion/storage systems is to exploit an efficient bifunctional electrocatalyst both for oxygen reduction reaction (ORR) and oxygen evolution ...reaction (OER) with low cost and good durability. Here, we synthesized chlorine-doped Co(OH)2 in situ grown on carbon cloth (Cl-doped Co(OH)2) as an integrated electrode by a facial electrodeposition method. The anodic potential was then applied to the Cl-doped Co(OH)2 in an alkaline solution to remove chlorine atoms (electro-oxidation (EO)/Cl-doped Co(OH)2), which can further enhance the electrocatalytic activity without any thermal treatment. EO/Cl-doped Co(OH)2 exhibits a better performance both for ORR and OER in terms of activity and durability because of the formation of a defective structure with a larger electrochemically active surface area after the electrochemical oxidation. This approach provides a new idea for introducing defects and developing active electrocatalyst.
•Electrodeposition of p-type nickel oxide (NiO) using anodic potentiostatic and cyclic voltammetry.•Applying both NiO as the hole transport layer (HTL) in the fabrication of polymer solar cells.•NiO ...synthesized by the anodic potentiostatic exhibited the best features as the HTL.•The best PSC showed JSC, VOC, FF, and PCE of 10.95 mA/cm2, 0.64 V, 0.60 and 4.21 %, respectively.
Hole transport layers (HTLs) are one of the most important components of bulk heterojunction polymer solar cells (BHJ PSCs), having functions of optimizing interface, adjusting the energy match, and helping obtain higher PCE. Inorganic p-type semiconductors are alternative HTLs due to their chemical stability, high mobility, high transparency, and applicable valence band (VB) energy level. In this work, interlayer engineering in BHJ PSC was performed using solution-processed p-type nickel oxide (NiO) as the HTL. NiO nanostructures were synthesized by anodic potentiostatic and cyclic voltammetry (CV) electrodeposition methods. Simple adjustment of the applied potential regime and electrodeposition parameters led to considerable structural and electrochemical changes in the resulting NiO. Eventually, the best sample was selected in terms of suitable surface conductivity, high optical transparency, and appropriate energy levels. NiO nanostructures with FCC crystal structure synthesized by anodic potentiostatic electrodeposition showed conductivity of 0.038 mS.cm−1 and charge mobility of 2.01 cm2.V−1s−1, respectively, about 30.2 % and 24.8 % higher than the NiO synthesized by CV. The anodic potentiostatic electrodeposition method increased the photovoltaic performance of the PSCs by 43 % compared to the CV method. The average power conversion efficiencies for the anodic potentiostatic and CV methods were 2.95 % and 4.21 %, respectively. The PCE of these cells was about 13 % and 62 % higher than that considered for the reference device prepared based on the PEDOT:PSS HTL.
AuPt Bimetal has been successfully synthesized by electrodeposition method with potentiostat technique. By varying the concentration of Au ions in the solution they are able to control the morphology ...and composition of the synthesized sample. The morphology obtained from the AuPt synthesis is cauliflower. The effect of Au ion concentration in solution on the catalytic performance of AuPt, the greater the Au concentration, the greater the current density in the electrooxidation reaction. In addition, the concentration of Au ions in the solution affects the results of the deposition of Au and Pt elements. In the study of AuPt nanocatalysts with a 0.4 mM Au ion concentration in an electrolyte solution, it was shown to have good catalytic activity in the ethanol electrooxidation reaction, with the resulting current densities and If/Ib of 10.1 mA/cm2 and 43.53 mA/cm2, respectively. This is an implication of many Au compositions which are known to have the ability to absorb and oxidize CO to encourage an increase in current density and increase its catalytic activity.
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•The rapid method of electro-deposition was used to load PANI on GF.•It overcomes the secondary pollution coming from traditional EF.•Graphite N was the active catalytic site for the ...production of H2O2.•Pyrrolic-N enhanced the PFOA adsorption capacity of the cathode.
The present study describes the coating of modified graphite felt (GF) with graphene (GE) and polyaniline (PANI). GF was doped with nitrogen atoms by a series of modification and electrolyticdeposition. Tests of different types of N content and cathodic catalytic oxidation performance confirmed that the graphite N introduction promoted the production of H2O2 in the 2e- process. Pyridine N catalyzed the H2O2 decomposition to produce •OH. The amount of H2O2 produced by GF, GF-GE, and GF-GE@PANI system was 11 mg L-1, 70 mg L-1, and 180 mg L-1, respectively. The doping of graphene increased H2O2 yield, and the electrolyticdeposition of PANI converted H2O2 to •OH rapidly. It was proved that the N atom provided by graphene was graphite N, which was the active catalytic site for the production of H2O2. The perfluorooctanoic acid (PFOA) removal at 180 min was 24.1% and 49.8% in the GF and GF-GE systems, respectively. The GF-GE@PANI system achieved 100% PFOA removal within 160 min. It was demonstrated that the enrichment of PANI with pyridine N provided many active sites for improving the conversion of H2O2 to •OH and in-situ degrading organic pollutants, offering an alternative for wastewater treatment.
•In this work, a facile photo-assisted electrodeposition method is used to report the effect of NiOOH cocatalyst on the PEC water splitting performance of hematite.•This preparation method is simple ...and provides a substantial number of catalytic active sites.•OER current approximately increases fourfold than conventional hematite photoanode.•Lower charge transfer resistance at the interface promotes hole transfer and consumption.
This study adopted a photo-assisted electrodeposition method to fabricate NiOOH on α-Fe2O3 photoanode. The detailed microstructure and chemical composition characterizations suggested that the NiOOH particles were selectively deposited on the α-Fe2O3 surface to form hybrid nanocomposites. Photoelectrochemical measurements revealed the important role of NiOOH as a cocatalyst for water splitting under visible light illumination. The prepared photoanode exhibited essentially enhanced photoelectrochemical activity, which was about fourfold higher than that of α-Fe2O3 photoanode. Further study suggested that loading NiOOH by photo-assisted electrodeposition method on α-Fe2O3 surface can facilitate the water splitting process by providing substantial active reaction sites and promoting the transfer and consumption of photogenerated holes. Contribution of this work is to supply a facile method to develop efficient photoelectrochemical anode.
In this study, NiOOH cocatalyst has been loaded by photo-assisted electrodeposition on the surface of hematite, which has promoted the selective distribution of cocatalysts on the surface of α-Fe2O3. Furthermore, photoelectrochemical measurements revealed the important role of NiOOH as cocatalysts in water splitting under visible light illumination. The nanocomposites displayed considerable enhanced photoelectrochemical activity, which was about fourfold higher than that of α-Fe2O3 photoanode. Further study indicated that loading NiOOH on Fe2O3 can facilitate the water splitting process by providing more active reaction sites and promoting the transfer and consumption of photogenerated holes. Contribution of this work is to supply a facile method to develop efficient photoelectrochemical anode.
Schematic model of the enhanced PEC performance on α-Fe2O3@NiOOH-ph photoanode Display omitted
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•Magnetic sediment co-electrodeposition (MSCD) mechanism of Ni-Al2O3 nanocomposites.•Coating morphology, crystal structucture, e, microhardness, nanoparticles loading and zeta ...potential were the main criteria.•Two phenomena control MSCD: (i) magnetohydrodynamic (MHD) and (ii) gravitational force.•MHD predominates for nano-sized particles (<100 nm) by reducing the thickness of the diffusion layer.•Gravitational force is dominant for agglomerated particles (>300 nm).
Our focus in this work is to exploit a mechanistic view of magnetic sediment co-electrodeposition (MSCD). Ni-Al2O3 nanocomposite coatings were electrodeposited in the presence and absence of an external magnetic field using sediment co-deposition (SCD) cell design. The dispersion, zeta potential, and size of Al2O3 particles in solution were measured and interpreted for the MSCD mechanism. The effectsof magnetic field on morphology, crystallographic texture, microhardness, dispersion of Al2O3 nanoparticles in Ni metal matrix were studied and a co-deposition kinetic model was accordingly postulated. Magnetic sediment co-electrodeposition not only changes the surface morphology of Ni-A2O3 from pyramidal-shaped to spherical grains, but it also increases the microhardness (from 365 to 500 HV) by decreasing the crystallite size (from 130 to 110 nm). Calculations of relative texture coefficient (RTC) values and Rietveld analysis showed that the growth of texture (200) of Ni-Al2O3 composite coatings is reinforced in the presence of a magnetic field. Based on our assumed model, two determining phenomena control the magnetic sediment co-deposition process: (i) magnetohydrodynamic (MHD) and (ii) gravitational force. MHD predominates for nano-sized particles (<100 nm) by reducing the thickness of the diffusion layer, whereas, the gravitational force is dominant for agglomerated particles (greater than300 nm).
Electrodeposition from plating baths containing 3,5-diamino-1,2,4-triazole (DAT) as an inhibitor gives Cu films exhibiting high surface area and high CO2 reduction activities. By changes in the pH ...and deposition current density, the morphologies of the Cu films are varied to exhibit wire, dot, and amorphous structures. Among these Cu films, the CuDAT-wire samples exhibit the best CO2 reduction activities activity with a Faradaic efficiency (FE) for C2H4 product formation reaching 40% at −0.5 V vs RHE, a FE for C2H5OH formation reaching 20% at −0.5 V vs RHE, and a mass activity for CO2 reduction at −0.7 V vs RHE of ∼700 A/g.
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