scholarly journals Highly Efficient and Stable Hydrogen Production in All pH Range by Two-Dimensional Structured Metal-Doped Tungsten Semicarbides

Research ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Edison H. Ang ◽  
Khang N. Dinh ◽  
Xiaoli Sun ◽  
Ying Huang ◽  
Jun Yang ◽  
...  
Keyword(s):  
Density Functional ◽  
Functional Theory ◽  
Faradaic Efficiency ◽  
Long Term Stability ◽  
Optimal Value ◽  
Tafel Slopes ◽  
Electrochemical Water Splitting ◽  
Ph Range ◽  
Metal Doped

Transition-metal-doped tungsten semicarbide nanosheets (M-doped W2C NSs, M=Fe, Co, and Ni) have been synthesized through carburization of the mixture of tungsten trioxide, polyvinylpyrrolidone, and metal dopant. The nanosheets grow directly on the W mesh and have the lateral dimension of several hundreds of nm to a few μm with a thickness of few tens nm. It is demonstrated that the M-doped W2C NSs exhibit superior electrocatalytic activity for hydrogen evolution reaction (HER). Impressively, the Ni-doped W2C NSs (2 at% Ni) with the optimized HER activity show extremely low onset overpotentials of 4, 9, and 19 mV and modest Tafel slopes of 39, 51, and 87 mV dec−1 in acidic (pH=0), neutral (pH=7.2), and basic (pH=14) solutions, respectively, which is close to the commercial Pt/C catalyst. Density functional theory (DFT) calculations also demonstrate that the Gibbs free energy for H adsorption of Ni-W2C is much closer to the optimal value ∆GH⁎ = -0.073 eV as compared to -0.16 eV of W2C. Furthermore, nearly 100% Faradaic efficiency and long-term stability are obtained in those environments. This realization of highly tolerant metal semicarbide catalyst performing on par with commercial Pt/C in all range of pH offers a key step towards industrially electrochemical water splitting.

Fabrication of CuOx nanowires@NiMnOx nanosheets core@shell-type electrocatalysts: crucial roles of defect modification and valence states for overall water electrolysis

2020 ◽  
Vol 8 (32) ◽  
pp. 16463-16476
Author(s):  
Suchada Sirisomboonchai ◽  
Xiumin Li ◽  
Nutthaphak Kitiphatpiboon ◽  
Rinrada Channoo ◽  
Shasha Li ◽  
...  
Keyword(s):  
Water Electrolysis ◽  
Core Shell ◽  
Faradaic Efficiency ◽  
Cu Nanowires ◽  
Long Term Stability ◽  
Valence States ◽  
Ph Range ◽  
Cu Foam

A bifunctional Cu nanowires@NiMn oxide nanosheet electrocatalyst was in situ grown on Cu foam for overall water splitting, exhibiting high activity in the pH range of 7–14 with excellent long-term stability and high faradaic efficiency.

Density functional theory studies of transition metal doped Ti3N2 MXene monolayer

2021 ◽  
Vol 197 ◽  
pp. 110613
Author(s):  
Ijeoma Cynthia Onyia ◽  
Stella Ogochukwu Ezeonu ◽  
Dmitri Bessarabov ◽  
Kingsley Onyebuchi Obodo
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Density Functional ◽  
Functional Theory ◽  
Metal Doped

scholarly journals Highly CO Selective Trimetallic Metal-Organic Framework Electrocatalyst for the Electrochemical Reduction of CO2

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 537
Author(s):  
Tran-Van Phuc ◽  
Jin-Suk Chung ◽  
Seung-Hyun Hur
Keyword(s):  
High Current Density ◽  
Metal Organic Framework ◽  
Faradaic Efficiency ◽  
Onset Potential ◽  
Long Term Stability ◽  
Metal Organic ◽  
Reduction Of Co2 ◽  
Electrocatalytic Reduction Of Co2 ◽  
Organic Framework

Pd, Cu, and Zn trimetallic metal-organic framework electrocatalysts (PCZs) based on benzene-1,3,5-tricarboxylic were synthesized using a simple solvothermal synthesis. The as-synthesized PCZ catalysts exhibited as much as 95% faradaic efficiency towards CO, with a high current density, low onset potential, and excellent long-term stability during the electrocatalytic reduction of CO2.

Electronic Structure and Optical Properties of Non-Metals (N, F, P, Cl, S)-Doped Cubic NaTaO3 by Density Functional Theory

2009 ◽  
Vol 79-82 ◽  
pp. 1245-1248 ◽  
Author(s):  
Pei Lin Han ◽  
Xiao Jing Wang ◽  
Yan Hong Zhao ◽  
Chang He Tang
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Electronic Structure ◽  
Visible Light ◽  
Absorption Edge ◽  
Density Functional ◽  
Red Shift ◽  
Functional Theory ◽  
Photoactive Materials ◽  
Metal Doped

Electronic structure and optical properties of non-metals (N, S, F, P, Cl) -doped cubic NaTaO3 were investigated systematically by density functional theory (DFT). The results showed that the substitution of (N, S, P, Cl) for O in NaTaO3 was effective in narrowing the band-gap relative to the F-doped NaTaO3. The larger red shift of the absorption edge and the higher visible light absorption at about 520 nm were found for the (N and P)-doped NaTaO3. The excitation from the impurity states to the conduction band may account for the red shift of the absorption edge in an electron-deficiency non-metal doped NaTaO3. The obvious absorption in the visible light region for (N and P)-doped NaTaO3 provides an important guidance for the design and preparation of the visible light photoactive materials.

Oxygen-evolution reactions (OER) on transition-metal-doped Fe3Co(PO4)4 iron-phosphate surfaces: a first-principles study

2021 ◽  
Author(s):  
Yogeshwaran Krishnan ◽  
Sateesh Bandaru ◽  
Niall J. English
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Oxygen Evolution ◽  
First Principles ◽  
Density Functional ◽  
Iron Phosphate ◽  
Functional Theory ◽  
First Principles Study ◽  
Metal Doped ◽  
Catalyst Surfaces

A series of transition-metal-doped Fe1−xMxCo(PO4)4(010) and Fe3Co1−xMx(PO4)4(010) electro-catalyst surfaces (with M = Mn, Os, Ru, Rh and Ir) have been modelled via density-functional theory (DFT) to gauge their oxygen-evolution reactions (OER).

A comparative study of structural, electronic and optical properties based on metal-doped methylammonium lead halidesviafirst-principles calculations

2019 ◽  
Vol 43 (24) ◽  
pp. 9453-9457 ◽  
Author(s):  
Diwen Liu ◽  
Huijuan Jing ◽  
Rongjian Sa ◽  
Kechen Wu
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Solar Cells ◽  
Comparative Study ◽  
Density Functional ◽  
Perovskite Solar Cells ◽  
Functional Theory ◽  
Electronic And Optical Properties ◽  
Metal Doped

To reduce the toxicity of Pb in perovskite solar cells, the structural stabilities, and electronic and optical properties of the mixed perovskites MAPb0.75B0.25I3(B = Mg, Ca, Sr, and Ba) were predicted using density functional theory.

The adsorption of nitrogen oxides on noble metal-doped graphene: The first-principles study

2019 ◽  
Vol 33 (04) ◽  
pp. 1950044 ◽  
Author(s):  
X. Jia ◽  
L. An
Keyword(s):  
Gas Sensors ◽  
First Principles ◽  
Density Functional ◽  
Noble Metals ◽  
Functional Theory ◽  
Adsorption Effect ◽  
Charge Densities ◽  
Adsorption Of Nitrogen ◽  
Doped Graphene ◽  
Metal Doped

The first-principles method based on density functional theory has been used to investigate the adsorption performance of NO/NO2 molecules on intrinsic, Ag-doped, Pt-doped and Au-doped graphene. Results show that graphene doped with Ag/Pt/Au has shorter final adsorption distance, larger adsorption energy and charge transfer amount with NO/NO2 molecules than intrinsic graphene, and the charge densities of doped graphene and NO/NO2 molecules overlap effectively. Therefore, doping graphene with noble metals can greatly enhance the adsorption between graphene and NO/NO2 molecules. Analysis also reveals that Au-doped graphene has the strongest adsorption effect on NO/NO2 molecules, followed by Ag-doped graphene, while Pt-doped graphene has the weakest role on the adsorption of NO/NO2 molecules. The work conducted in this research provides a theoretical guidance for the application of NO/NO2 gas sensors based on graphene.

Sign in / Sign up

Export Citation Format

Share Document