scholarly journals Semiconductive Microporous Hydrogen-Bonded Organophosphonic Acid Frameworks

2020 ◽  
Author(s):  
Patrik Tholen ◽  
Craig A. Peeples ◽  
Raoul Schaper ◽  
Ceyda Bayraktar ◽  
Turan Erkal ◽  
...  
Keyword(s):  
Band Gap ◽  
Density Functional ◽  
Printed Electronics ◽  
High Surface ◽  
Density Functional Theory Calculations ◽  
Thermal Stabilities ◽  
Phenylphosphonic Acid ◽  
Surface Areas ◽  
New Family ◽  
Hydrogen Bonded

<p>We report the first semiconductive, proton-conductive, microporous hydrogen-bonded organic framework (HOF) derived from phenylphosphonic acid and 5,10,15,20‐tetrakis[<i>p</i>‐phenylphosphonic acid] porphyrin (known as GTUB5). The structure of GTUB5 was characterized using single crystal X-ray diffraction (XRD). A narrow band gap of 1.56 eV was extracted from a UV-Vis spectrum of pure GTUB5 crystals, in excellent agreement with the 1.65 eV band gap obtained from density functional theory calculations. The same band gap was also measured for GTUB5 in DMSO. The proton conductivity of GTUB5 was measured to be 3.00 ´ 10<sup>-6 </sup>S cm<sup>-1</sup> at 75 °C and 75 % relative humidity. The surface area of GTUB5’s hexagonal voids were estimated to be 422 m<sup>2</sup> g<sup>-1</sup> from grand canonical Monte Carlo simulations. XRD showed that GTUB5 is thermally stable under relative humidities of up to 90 % at 90 °C. These findings pave the way for a new family of microporous, organic, semiconducting materials with high surface areas and high thermal stabilities. Such materials could find applications in printed electronics, optoelectronics, and electrodes in supercapacitors.<br></p>

scholarly journals Semiconductive Microporous Hydrogen-Bonded Organophosphonic Acid Frameworks

2020 ◽  
Author(s):  
Patrik Tholen ◽  
Craig A. Peeples ◽  
Raoul Schaper ◽  
Ceyda Bayraktar ◽  
Turan Erkal ◽  
...  
Keyword(s):  
Band Gap ◽  
Density Functional ◽  
Printed Electronics ◽  
High Surface ◽  
Density Functional Theory Calculations ◽  
Thermal Stabilities ◽  
Phenylphosphonic Acid ◽  
Surface Areas ◽  
New Family ◽  
Hydrogen Bonded

<p>We report the first semiconductive, proton-conductive, microporous hydrogen-bonded organic framework (HOF) derived from phenylphosphonic acid and 5,10,15,20‐tetrakis[<i>p</i>‐phenylphosphonic acid] porphyrin (known as GTUB5). The structure of GTUB5 was characterized using single crystal X-ray diffraction (XRD). A narrow band gap of 1.56 eV was extracted from a UV-Vis spectrum of pure GTUB5 crystals, in excellent agreement with the 1.65 eV band gap obtained from density functional theory calculations. The same band gap was also measured for GTUB5 in DMSO. The proton conductivity of GTUB5 was measured to be 3.00 ´ 10<sup>-6 </sup>S cm<sup>-1</sup> at 75 °C and 75 % relative humidity. The surface area of GTUB5’s hexagonal voids were estimated to be 422 m<sup>2</sup> g<sup>-1</sup> from grand canonical Monte Carlo simulations. XRD showed that GTUB5 is thermally stable under relative humidities of up to 90 % at 90 °C. These findings pave the way for a new family of microporous, organic, semiconducting materials with high surface areas and high thermal stabilities. Such materials could find applications in printed electronics, optoelectronics, and electrodes in supercapacitors.<br></p>

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.

scholarly journals Effect of Hartree–Fock pseudopotentials on local density functional theory calculations

2018 ◽  
Vol 20 (27) ◽  
pp. 18844-18849 ◽  
Author(s):  
Hengxin Tan ◽  
Yuanchang Li ◽  
S. B. Zhang ◽  
Wenhui Duan
Keyword(s):  
Density Functional Theory ◽  
Band Gap ◽  
Density Functional ◽  
Local Density ◽  
Density Functional Theory Calculations ◽  
Optimal Choice ◽  
Functional Theory ◽  
Hartree Fock ◽  
Local Density Functional Theory ◽  
Local Density Functional

Optimal choice of the element-specific pseudopotential improves the band gap.

Two-dimensional metal-organic frameworks Mo3(C2O)12 as promising single-atom catalysts for selective nitrogen-to-ammonia

2022 ◽  
Author(s):  
Zhen Feng ◽  
Zelin Yang ◽  
Xiaowen Meng ◽  
Fachuang Li ◽  
Zhanyong Guo ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Metal Organic Frameworks ◽  
Density Functional Theory Calculations ◽  
Reduction Reaction ◽  
Single Atom ◽  
Two Dimensional ◽  
Functional Theory ◽  
New Family ◽  
Metal Organic

The development of single-atom catalysts (SACs) for electrocatalytic nitrogen reduction reaction (NRR) remains a great challenge. Using density functional theory calculations, we design a new family of two-dimensional metal-organic frameworks...

Graphene-Based Sensors for Monitoring Strain

2013 ◽  
Vol 3 (1) ◽  
pp. 74-83
Author(s):  
M. Mirnezhad ◽  
R. Ansari ◽  
H. Rouhi ◽  
M. Faghihnasiri
Keyword(s):  
Fermi Level ◽  
Band Gap ◽  
Strain Distribution ◽  
Density Functional ◽  
Tight Binding ◽  
Density Functional Theory Calculations ◽  
Generalized Gradient ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Gap Opening

The application of graphene as a nanosensor in measuring strain through its band structure around the Fermi level is investigated in this paper. The mechanical properties of graphene as well as its electronic structure are determined by using the density functional theory calculations within the framework of generalized gradient approximation. In the case of electronic properties, the simulations are applied for symmetrical and asymmetrical strain distributions in elastic range; also the tight-binding approach is implemented to verify the results. It is indicated that the energy band gap does not change with the symmetrical strain distribution but depend on the asymmetric strain distribution, increasing strain leads to band gap opening around the Fermi level.

Electronic structures and optical properties of cuprous oxide and hydroxide

2014 ◽  
Vol 1675 ◽  
pp. 185-190
Author(s):  
Yunguo Li ◽  
Cláudio M. Lousada ◽  
Pavel A. Korzhavyi
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Cuprous Oxide ◽  
Density Functional ◽  
Spent Nuclear Fuel ◽  
Energy Levels ◽  
Chemical Properties ◽  
Density Functional Theory Calculations ◽  
Hybrid Functional ◽  
Indirect Band Gap

ABSTRACTThe broad range of applications of copper, including areas such as electronics, fuel cells, and spent nuclear fuel disposal, require accurate description of the physical and chemical properties of copper compounds. Within some of these applications, cuprous hydroxide is a compound whose relevance has been recently discovered. Its existence in the solid-state form was recently reported. Experimental determination of its physical-chemical properties is challenging due to its instability and poop crystallinity. Within the framework of density functional theory calculations (DFT), we investigated the nature of bonding, electronic spectra, and optical properties of the cuprous oxide and cuprous hydroxide. It is found that the hybrid functional PBE0 can accurately describe the electronic structure and optical properties of these two copper(I) compounds. The calculated properties of cuprous oxide are in good agreement with the experimental data and other theoretical results. The structure of cuprous hydroxide can be deduced from that of cuprous oxide by substituting half Cu+ in Cu2O lattice with protons. Compared to Cu2O, the presence of hydrogen in CuOH has little effect on the ionic nature of Cu–O bonding, but lowers the energy levels of the occupied states. Thus, CuOH is calculated to have a wider indirect band gap of 2.73 eV compared with the Cu2O band gap of 2.17 eV.

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