scholarly journals Density Functional Theory study of Cu doped {0001} and {012} surfaces of hematite for water splitting

MRS Advances ◽  
2018 ◽  
Vol 3 (13) ◽  
pp. 669-678 ◽  
Author(s):  
Joseph Simfukwe ◽  
Refilwe Edwin Mapasha ◽  
Artur Braun ◽  
Mmantsae Diale
Keyword(s):  
Density Functional Theory ◽  
Water Splitting ◽  
Water Oxidation ◽  
Density Functional ◽  
Band Alignment ◽  
Oxidation Activity ◽  
Functional Theory ◽  
External Bias ◽  
Charge Density Difference ◽  
Favorable Conditions

ABSTRACTDensity Functional Theory (DFT) calculations study of Cu doped {0001} and {01-12} surfaces of hematite for enhanced water splitting have been carried out. The doping was restricted to planes in the vicinity of the surface, specifically from the top most layers to the third inner layer of Fe atoms. Thermodynamic stabilities were evaluated based on surface energies and formation energies. The evaluation of thermodynamic stabilities (negative formation energy values) shows that the systems are thermodynamically stable which suggest that they can be synthesized in the laboratory under favorable conditions. Doping on the top most layer yields the energetically most favorable structure. The calculated charge density difference plots showed the concentration of charge mainly at the top of the surface (termination region), and this charge depleted from the Cu atom to the surrounding Fe and O atoms. This phenomenon (concentration of charge at the top of the surface) is likely to reduce the distance moved by the charge carriers, decrease in charge recombination leading to facile transfer of charge to the adsorbate and, suggesting improved photoelectrochemical water oxidation activity of hematite. The analysis of electron electronic structure reveals that Cu doped surface systems does not only decrease the band gap but also leads to the correct conduction band alignment for direct water splitting without external bias voltage.

scholarly journals Tuning the optoelectronic properties of hematite with rhodium doping for photoelectrochemical water splitting using density functional theory approach

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdur Rauf ◽  
Muhammad Adil ◽  
Shabeer Ahmad Mian ◽  
Gul Rahman ◽  
Ejaz Ahmed ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Optical Absorption ◽  
Water Splitting ◽  
Density Functional ◽  
Formation Energy ◽  
Visible Region ◽  
Photoelectrochemical Water Splitting ◽  
Theory Approach ◽  
Functional Theory

AbstractHematite (Fe2O3) is one of the best candidates for photoelectrochemical water splitting due to its abundance and suitable bandgap. However, its efficiency is mostly impeded due to the intrinsically low conductivity and poor light absorption. In this study, we targeted this intrinsic behavior to investigate the thermodynamic stability, photoconductivity and optical properties of rhodium doped hematite using density functional theory. The calculated formation energy of pristine and rhodium doped hematite was − 4.47 eV and − 5.34 eV respectively, suggesting that the doped material is thermodynamically more stable. The DFT results established that the bandgap of doped hematite narrowed down to the lower edge (1.61 eV) in the visible region which enhanced the optical absorption and photoconductivity of the material. Moreover, doped hematite has the ability to absorb a broad spectrum (250–800) nm. The enhanced optical absorption boosted the photocurrent and incident photon to current efficiency. The calculated results also showed that the incorporation of rhodium in hematite induced a redshift in optical properties.

Understanding the advantage of hexagonal WO3 as an efficient photoanode for solar water splitting: a first-principles perspective

2016 ◽  
Vol 4 (29) ◽  
pp. 11498-11506 ◽  
Author(s):  
Taehun Lee ◽  
Yonghyuk Lee ◽  
Woosun Jang ◽  
Aloysius Soon
Keyword(s):  
Density Functional Theory ◽  
Band Gap ◽  
Water Splitting ◽  
Anode Material ◽  
First Principles ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Good Alternative ◽  
Functional Theory ◽  
Solar Water Splitting

Using first-principles density-functional theory calculations, we investigate the advantage of using h-WO3 (and its surfaces) over the larger band gap γ-WO3 phase for the anode in water splitting. We demonstrate that h-WO3 is a good alternative anode material for optimal water splitting efficiencies.

A systematic computational investigations of water splitting and N2 reduction reaction performances of monolayer MBenes

2021 ◽  
Author(s):  
Yuwen Cheng ◽  
Jisheng Mo ◽  
Yongtao Li ◽  
Yan Song ◽  
Yumin Zhang
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Water Splitting ◽  
Density Functional ◽  
Reduction Reaction ◽  
Functional Theory ◽  
Energy Conversion And Storage ◽  
Metal Borides ◽  
Potential Applications ◽  
And Storage

Recently, transition metal borides (MBenes, analogous to MXenes) have been attracted interest due to their potential applications in energy conversion and storage. In this work, we performed density functional theory...

Prediction of Beryllium Clusters from First Principles: Be17 as a Promising New Material for Water Splitting

2021 ◽  
Author(s):  
Behnaz Abyaz ◽  
Zabiollah Mahdavifar ◽  
Georg Schreckenbach ◽  
Yang Gao
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Water Splitting ◽  
First Principles ◽  
Density Functional ◽  
Global Minimum ◽  
Functional Theory ◽  
New Material ◽  
Universal Structure

Evolutionary searches using the USPEX method (Universal Structure Predictor: Evolutionary Xtallography) combined with density functional theory (DFT) calculations were performed to obtain the global minimum structures of beryllium (Ben, n=3-25)...

Exploring the Photovoltaic Properties of Metal Bipyridine Complexes (Metal = Fe, Zn, Cr, and Ru) by Density Functional Theory

2018 ◽  
Vol 73 (4) ◽  
pp. 337-344 ◽  
Author(s):  
Ahmad Irfan ◽  
Ghulam Abbas
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Photovoltaic Performance ◽  
Open Circuit ◽  
Band Alignment ◽  
Structure Property ◽  
Ambient Conditions ◽  
Photovoltaic Properties ◽  
Functional Theory ◽  
Solar Cell Performance

AbstractThe synthesis and characterisation of mononuclear Fe complexes were carried out by using bipyridine (Compound 1) at ambient conditions. Additionally, three more derivatives were designed by substituting the central Fe metal with Zn, Cr, and Ru (Compound 2, Compound 3, and Compound 4), respectively. The ground state geometry calculations were carried out by using density functional theory (DFT) at B3LYP/6-31G** (LANL2DZ) level of theory. We shed light on the frontier molecular orbitals, electronic properties, photovoltaic parameters, and structure–property relationship. The open-circuit voltage is a promising parameter that considerably affects the photovoltaic performance; thus, we have estimated its value by considering the complexes as donors whereas TiO2 and/or Si were used as acceptors. The solar cell performance behaviour was also studied by shedding light on the band alignment and energy level offset.

Ruthenium-based catalysts for water oxidation: the key role of carboxyl groups as proton acceptors

2020 ◽  
Vol 22 (9) ◽  
pp. 5249-5254 ◽  
Author(s):  
Yuting Liu ◽  
Xiaofang Su ◽  
Wei Guan ◽  
Likai Yan
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Water Oxidation ◽  
Density Functional ◽  
Carboxyl Groups ◽  
Functional Theory

In this work, the mechanism of water oxidation catalyzed by an Ru-based complex [Ru(L)]+ (L = 5,5-chelated 2-carboxy-phen, 2,2′;6′,2′′-terpyridine) was studied by density functional theory (DFT) calculations.

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