Electronically defective tellurium-doped TiO2 catalysts for enhanced photoelectrochemical water splitting

Fawzy, Samar M.; Khedr, Ghada E.; Allam, Nageh K.

doi:10.1016/j.ijhydene.2023.05.037

Cited by 25 publications

(13 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This significantly inhibits the HER process. According to the literature reports, the higher the positive charge of the metal, the greater the Faradaic efficiency. − Also, HER was investigated as depicted in Figure e. It is noticed that Fe SAC -N-C is not favored for HER as the H + intermediates have positive free energies for @Fe and @N active sites of 0.61 and 0.94 eV, respectively.…”

Section: Resultsmentioning

confidence: 94%

“…It is noticed that Fe SAC -N-C is not favored for HER as the H + intermediates have positive free energies for @Fe and @N active sites of 0.61 and 0.94 eV, respectively. The positive free energy indicates the weak affinity for H + to bind with the Fe SAC -N-C. − Hence, HER would not be competitive to NRR. The remarkable NRR performance of the Fe SAC -N-C catalyst can be attributed to its low energy barrier for the rate-determining step toward NRR and idle HER mechanism.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Fe-Single-Atom Catalysts on Nitrogen-Doped Carbon Nanosheets for Electrochemical Conversion of Nitrogen to Ammonia

Agour,

Elkersh,

Khedr

et al. 2023

ACS Appl. Nano Mater.

Self Cite

View full text Add to dashboard Cite

Electrochemical nitrogen reduction reaction (NRR) has been established as a promising and sustainable alternative to the Haber−Bosch process, which requires intensive energy to produce ammonia. Unfortunately, NRR is constrained by the high adsorption/activation of the N 2 energy barrier and the competing hydrogen evolution reaction, resulting in low faradic efficiency. Herein, a well-dispersed iron single-atom catalyst was successfully immobilized on nitrogen-doped carbon nanosheets (Fe SAC -N-C) synthesized from pre-hydrothermally derived Fe-doped carbon quantum dots with an average particle size of 2.36 nm and used for efficient electrochemical N 2 fixation at ambient conditions. The as-synthesized Fe SAC -N-C catalyst records an onset potential of 0.12 V RHE , exhibiting a considerable faradic efficiency of 23.7% and an NH 3 yield rate of 3.47 μg h −1 cm −2 in aqueous 0.1 M KOH electrolyte at a potential of −0.1 V RHE under continuous N 2 feeding conditions. The control experiments assert that the produced NH 3 molecules only emerge from the dissolved N 2 -gas, reflecting the remarkable stability of the nitrogen−carbon framework during electrolysis. The DFT calculations showed the Fe SAC -N-C catalyst to demonstrate a lower energy barrier during the rate-limiting step of the NRR process, consistent with the observed high activity of the catalyst. This study highlights the exceptional potential of single-atom catalysts for electrochemical NRR and offers a comprehensive understanding of the catalytic mechanisms involved. Ultimately, this work provides a facile synthesis strategy of Fe SAC -N-C nanosheets with high atomic-dispersion, creating a novel design avenue of Fe SAC -N-C that can vividly have a potential applicability in the large spectrum of electrocatalytic applications.

show abstract

Section: Resultsmentioning

confidence: 94%

Section: Resultsmentioning

confidence: 99%

Fe-Single-Atom Catalysts on Nitrogen-Doped Carbon Nanosheets for Electrochemical Conversion of Nitrogen to Ammonia

Agour,

Elkersh,

Khedr

et al. 2023

ACS Appl. Nano Mater.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The photocurrent of the TW3 sample is 0.165 mA/cm 2 at 0.6 V SCE (Figure a), which might be ascribed to (i) the low-light responsivity of the material and (ii) the disparity in the degree of crystallinity of the existing phase structures compared to its counterparts, as observed by the XRD results. Furthermore, a large loss occurs in TW3 as a result of the inability to capture photons below the energy gap, compared to TW6 …”

Section: Resultsmentioning

confidence: 99%

“…Furthermore, a large loss occurs in TW3 as a result of the inability to capture photons below the energy gap, compared to TW6. 58 Also, the photoactivity of the TW4 sample slightly increased as the annealing temperature was increased to 400 °C, which may be ascribed to the increased growth of brookite and rutile crystalline structures with the previously formed anatase (Figures 5a and 2b). Following that, reaching 500 °C greatly increased the PEC performance, demonstrating that the fabricated photoelectrodes have a temperature-dependent performance, which is consistent with the optical observations (Figures 5a and 4a).…”

Section: Optical and Pec Propertiesmentioning

confidence: 93%

Transparent Sn-Decorated W-Doped TiO₂ Multiphase Nanotube Arrays as Efficient Photocatalysts for Solar-Driven Water Splitting

Elbanna,

Mohamed,

Ghanem

et al. 2024

ACS Appl. Eng. Mater.

Self Cite

View full text Add to dashboard Cite

Photoelectrochemical water splitting is a crucial step in realizing a green hydrogen economy. Herein, we demonstrate, for the first time, the rational design and optimized fabrication of earth-abundant W-doped TiO 2 thin nanotubular structures decorated with Sn in mixed polymorphs (anatase/brookite/rutile) on F-doped tin oxide substrates via a direct-current sputtering technique and subsequent electrochemical anodization followed by thermal treatment. Sn decoration and W doping along with optimized annealing conditions were elucidated as determinant factors controlling the structural and optical features of the fabricated nanotubes. The resulting highly crystalline polymorphic nanotubes showed an enhanced photocurrent at 0.4 V SCE (1.75 mA/cm 2 ) with a noticeable narrowing in the optical band gap and 25 times compared to pristine TiO 2 nanotubes. The photoluminescence spectra revealed enriched oxygen (O) vacancies upon doping with W and decoration with Sn. The Mott−Schottky plot unveils the variations in the density of charge carriers upon annealing at different temperatures and their role in annihilating these O vacancies. Importantly, the electrochemical impedance spectroscopy elucidation helps to reveal the charge-transfer mechanism in the mixed polymorph junctions of the fabricated nanotubes under dark and illumination conditions, revealing reduced charge-transfer resistance under light-on conditions, which is consistent with the produced photocurrent, lifetime of the electrons, and density of the impurity levels. Moreover, the density functional theory investigation unraveled the development of a homojunction between the brookite and rutile phases that improved the photocatalytic activity toward the oxygen evolution reaction, in agreement with the experimental findings. The findings of this work represent a crucial milestone toward the development of visible-light, earth-abundant, light-absorbing photoanodes for solar-assisted water splitting.

show abstract

“…Also, density functional theory (DFT) calculations were executed to scrutinize the electronic properties of oxysulfide structures, as DFT was proven to be a robust tool in examining the electronic properties. 27–32 To unveil the real functionality of the C 3 M 1 OS electrode, an asymmetric device was assembled employing commercial activated carbon (AC) as the negative pole and C 3 M 1 OS as the positive pole, with a weight of ∼4 mg, i.e. , commercial mass loading.…”

Section: Introductionmentioning

confidence: 99%

Compositionally variant bimetallic Cu–Mn oxysulfide electrodes with meritorious supercapacitive performance and high energy density

El Sharkawy,

Elbanna,

Khedr

et al. 2023

Energy Adv.

Self Cite

View full text Add to dashboard Cite

show abstract

Electronically defective tellurium-doped TiO2 catalysts for enhanced photoelectrochemical water splitting

Cited by 25 publications

References 36 publications

Fe-Single-Atom Catalysts on Nitrogen-Doped Carbon Nanosheets for Electrochemical Conversion of Nitrogen to Ammonia

Fe-Single-Atom Catalysts on Nitrogen-Doped Carbon Nanosheets for Electrochemical Conversion of Nitrogen to Ammonia

Transparent Sn-Decorated W-Doped TiO₂ Multiphase Nanotube Arrays as Efficient Photocatalysts for Solar-Driven Water Splitting

Compositionally variant bimetallic Cu–Mn oxysulfide electrodes with meritorious supercapacitive performance and high energy density

Contact Info

Product

Resources

About

Electronically defective tellurium-doped TiO2 catalysts for enhanced photoelectrochemical water splitting

Cited by 25 publications

References 36 publications

Fe-Single-Atom Catalysts on Nitrogen-Doped Carbon Nanosheets for Electrochemical Conversion of Nitrogen to Ammonia

Fe-Single-Atom Catalysts on Nitrogen-Doped Carbon Nanosheets for Electrochemical Conversion of Nitrogen to Ammonia

Transparent Sn-Decorated W-Doped TiO2 Multiphase Nanotube Arrays as Efficient Photocatalysts for Solar-Driven Water Splitting

Compositionally variant bimetallic Cu–Mn oxysulfide electrodes with meritorious supercapacitive performance and high energy density

Contact Info

Product

Resources

About

Transparent Sn-Decorated W-Doped TiO₂ Multiphase Nanotube Arrays as Efficient Photocatalysts for Solar-Driven Water Splitting