Review
Multidisciplinary Sciences
Jeffrey Roshan De Lile, Ashkan Bahadoran, Su Zhou, Jiujun Zhang
Summary: This study discusses the research on polaron in TiO2 for light-chemical energy conversion, introducing different first-principles methods and concepts to improve the efficiency of light-chemical energy conversion.
ADVANCED THEORY AND SIMULATIONS
(2022)
Article
Chemistry, Multidisciplinary
Kai Sellschopp, Gregor B. Vonbun-Feldbauer
Summary: Nature is able to create structurally complex materials with diverse properties using only a few organic compounds and minerals. This study focuses on nanocomposites made from TiO2 and carboxylic-acids, which can serve as a representative example of natural and bio-inspired materials. The research aims to understand the atomistic processes and failure mechanisms at the interfaces of these composites. The findings suggest that the failure at the TiO2/carboxylic-acid interfaces is primarily caused by surface failure rather than molecular de-bonding. The study also provides mechanical properties that can be compared with experimental results for further improvements in these materials.
Article
Chemistry, Multidisciplinary
Kai Sellschopp, Gregor B. Vonbun-Feldbauer
Summary: This study models the stress-strain curves of TiO2/carboxylic-acid interfaces and reveals the failure mechanisms and stress-release mechanisms at the interfaces. The calculated mechanical properties are qualitatively consistent with experimental results, which is important for improving these materials.
Article
Engineering, Chemical
Szu-Nung Kao, Ying-Chieh Hung, Yusuke Shimoyama, Chieh-Ming Hsieh, Bor Kae Chang
Summary: Recent research has shown a growing interest in developing titanium dioxide (TiO2) based anodes for lithium ion batteries due to their high theoretical specific capacity, safety, chemical stability, and abundance. Niobium-doped (Nb-doped) TiO2 anodes have been proposed and shown to improve cycling stability and performance in lithium ion batteries. The study used first principles calculations to reveal the mechanism behind the superior performance of Nb-doped TiO2 compared to pristine TiO2, showing improved lithium intercalation process and electronic conductivity.
JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS
(2021)
Article
Optics
Zhongliang Zeng, Mingyao Xu, Yunzhou Sun, Jiakun Xu, Yu Zhong
Summary: This study investigated the geometry structure, electronic structure, and optical properties of TiO2-anatase doped with N and N/P atoms using the plane-wave ultrasoft pseudopotential method based on first-principles density functional theory. Results showed additional states in the band gap and a narrowing band gap, enhancing the oxidation and reduction abilities of the doped TiO2-anatase. Experimental results confirmed the red shift phenomenon, increased oxygen vacancies, and improved photocatalytic properties in the N/P doped TiO2-anatase, validating the theoretical analysis.
Article
Materials Science, Multidisciplinary
S. Muthukrishnan, R. Vidya, Anja Olafsen Sjastad
Summary: Pure anatase TiO2 only has photocatalytic activity in the UV region of solar energy. External impurities can be added to reduce the band gap of TiO2 and enhance its absorption of the visible spectrum. This study investigated the effect of Sc and V mono-doping and co-doping on the electronic structure of pure anatase TiO2 using Density Functional Theory (DFT).
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Chemistry, Physical
Giovanni Di Liberto, Farahnaz Maleki, Gianfranco Pacchioni
Summary: This study conducted ab initio molecular dynamics simulations using density functional theory to investigate the pH-dependent surface chemistry of MgO, TiO2, and γ-Al2O3, successfully predicting the point-of-zero charge values and the proportions of charged species and neutral molecules on the surface as pH varies.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Jing Xu, Min Sun, Yinmei Mi, Lifang Xu
Summary: In this study, the adsorption behaviors of formaldehyde molecule on anatase TiO2 surface were investigated using first-principles method. It was found that the stable bidentate adsorption configuration involving surface bridging O-22 atom can cause surface bond breaking, and the pi bond of formaldehyde molecule to open. The bonding properties of the adsorption were analyzed in detail, revealing the coexistence of covalent and ionic bonding in the oxygen atoms involved.
CHEMICAL PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Yong Han, Tianyu Li, Qingrui Zhang, Xiaoqiang Guo, Tifeng Jiao
Summary: This study utilized density functional theory to investigate the impact of electrostatic fields on the properties of g-C3N4/TiO2 heterostructures. The results showed that applying electric fields in different directions leads to changes in binding energy, optical absorption spectra, and charge transfer numbers, improving the photocatalytic ability of the heterostructure.
Article
Physics, Condensed Matter
Xiangjiang Xiao, Jielei Tu, Zuming Liu, Jiahao Wu, Lei Liu
Summary: The structural and photoelectric properties of (Nb, Ta) codoped anatase TiO2 were investigated using first-principles calculations based on density functional theory and the Hubbard U correction. The results showed that the (Nb, Ta) codoping induced hybridized states, resulting in the n-type metallic characteristics and increased conductivity of Ti-0.Nb-875(0).0625Ta0.0625O2(I) compared to Ti-0.Nb-9375(0).O-0625(2). The distance between Nb and Ta atoms and the Nb doping concentration were found to affect the conductivity and mobility of the material. Additionally, (Nb, Ta) codoped anatase TiO2 exhibited shifts in the absorption edges towards the ultraviolet region and high transmittance due to its low absorption and reflection of visible light.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Chemistry, Multidisciplinary
Dongxiang Li, Ruiqin Li, Fanjin Zeng, Shuyi Wang, Wanjun Yan, Mingsen Deng, Shaohong Cai
Summary: In this study, the electronic and optical properties of Sc-doped, C-doped, and Sc/C-codoped TiO2 (101) surfaces were systematically investigated. It was found that the Sc/C-codoped TiO2 (101) surface exhibited the most enhanced absorption coefficient in the high energy region of visible light. The surface with 5.56% impurity concentration showed optimal photocatalytic performance in the visible region.
Article
Chemistry, Physical
Jacqueline Hidalgo-Jimenez, Taner Akbay, Tatsumi Ishihara, Kaveh Edalati
Summary: In this study, the high-pressure torsion method was used to stabilize the oxygen-deficient high-pressure phase of TiO2, columbite, as an active photocatalyst. The activity of columbite was found to be higher than that of the anatase phase. DFT calculations revealed that columbite has improved optical bandgap and light absorbance due to oxygen vacancies, as well as higher water adsorption energy and lower surface activation energy for water splitting.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Chemistry, Physical
Anum Shahid Malik, Lisa A. Fredin
Summary: Photocatalytic water splitting using rutile (100) surfaces as photocatalyst for water oxidation was systematically studied using density functional theory. The highest stability and activity were observed on fully covered (100) surfaces and surfaces with oxygen vacancies in the first two sublayers of the slab. The lowest overpotential for oxygen evolution was found on a reduced rutile (100) surface with a vacancy in the second subsurface oxygen layer, while the oxygen covered surface had a higher overpotential. The rate-limiting step in both cases was the transfer of a proton from a surface adsorbed OH to the electrolyte.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Lunwei Yang, Wei Xiao, Jianwei Wang, Xiao-Wu Li, Ligen Wang
Summary: This study compares the adsorption properties of various gases on graphene-based sensors and finds that oxygen functionalized graphene improves the selectivity for formaldehyde detection. The sensing properties of the sensors are evaluated and the predicted responses for formaldehyde detection are 76% and 32% in different directions. This research provides insights for designing graphene-based sensing materials with high selectivity.
Article
Chemistry, Multidisciplinary
Xiaogang Liu, Wenjie Chen, Xin Zhang
Summary: The introduction of carbon quantum dot (CQD) enhances the catalytic performance of Pd/TiO2 nanocomposites for generating H2 from formaldehyde (HCHO) solution at room temperature.
NEW JOURNAL OF CHEMISTRY
(2023)
Article
Physics, Condensed Matter
A. Jbeli, N. Zeiri, N. Yahyaoui, P. Baser, M. Said
Summary: The electronic and optical properties of CdSe/ZnSe semiconductor core/shell quantum dots with hydrogenic donor impurity were investigated theoretically. The perturbation and variational methods were used to calculate the binding energy, photoionization cross-section, polarizability, and diamagnetic susceptibility of the excited impurity under various conditions. A significant stark shift in the binding energy was observed under the influence of an external electric field.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Rahat Batool, Tariq Mahmood, Sajid Mahmood, Abdul Aziz Bhatti
Summary: This study investigates the effects of alkali metal doping (Na, K, Cs) on MAPbI3 through compositional engineering. The results show that doping Na, K, and Cs can improve the phase stability, thermodynamic stability, and optical absorption of MAPbI3.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
N. A. N. M. Nor, M. A. H. Razali, W. H. A. W. K. Annuar, N. N. Alam, F. N. Sazman, N. H. M. Zaki, A. S. Kamisan, A. I. Kamisan, M. H. Samat, A. M. M. Ali, O. H. Hassan, B. U. Haq, M. Z. A. Yahya, M. F. M. Taib
Summary: This study investigates the potential of quaternary chalcogenides semiconductors as thin film solar cell absorbers using density functional theory (DFT) and density functional theory plus Hubbard U (DFT + U) approach. The results show that by applying Hubbard U terms, the electronic band gaps can be accurately predicted, providing valuable insights for finding cost-effective new thin film solar cell materials.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Ashwani Kumar, Anuj Kumar, Mohaseen S. Tamboli, Mohd Ubaidullah, J. Jayarubi, S. K. Tripathi
Summary: In this study, lead-based perovskite solar cells are replaced by bismuth-based perovskite cells to overcome their instability and toxicity. CsBi3I10 perovskite films are fabricated using a modified drop-casting process, and the effects of post-annealing temperature on the morphological, structural, and optical properties are investigated. The photovoltaic performance of the cells without a hole transport layer is also quantitatively evaluated.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Yang Gao, Shu-Ming Chen, Shuo Cao, Shang-Zhou Zhang, Philippe Djemia, Qing-Miao Hu
Summary: This study investigates the phase stability, elastic modulus, and hardness of ternary nitride Ti1-xAlxN. It is found that the hardness increases with the Al content x. The cubic B1 structure is more stable for x < about 0.75, while the hexagonal structure (B4) is more stable for x > about 0.75. The composition dependent hardness and phase decomposition contribute to the convex shaped hardness curve of Ti1-xAlxN.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Fengqi Wang, Qinyan Ye, Xulin He, Kun Luo, Xiaolong Ran, Xingping Zheng, Cheng Liao, Ru Li
Summary: This report uses rigorous calculations based on density functional theory to study the piezoelectric and elastic properties of wurtzite aluminum nitride (w-AlN) with single- and co-alloying by Hf (or Zr) and Sc. The research finds that the (HfSc)0.375Al0.625N and (ZrSc)0.375Al0.625N with stable wurtzite phase have a large piezoelectric coefficient d33 of 49.18 pC/N and 47.00 pC/N, respectively. However, the piezoelectric voltage constant g33 and electromechanical coupling constant k233 of HfAlN, ZrAlN, HfScAlN, and ZrScAlN are smaller than that of ScAlN, which is attributed to the large dielectric constant epsilon 33 of Hf (or Zr) alloying samples. Furthermore, the calculations of internal parameter u and bond angle alpha elucidate the brittle-to-ductile transformation in alloying w-AlN crystal structure. Electronic structure calculations show that the bandgap decreases almost linearly with the increase of alloying concentration, and the Hf (or Zr) alloying compounds become n-type semiconductors due to the existing high-charge states.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
S. R. Athul, K. Arun, S. Swathi, U. D. Remya, Andrea Dzubinska, Marian Reiffers, Nagalakshmi Ramamoorthi
Summary: The magnetic and magnetocaloric characteristics of Ho6FeSb2 have been studied. The compound exhibits two second-order ferromagnetic transitions, enabling hysteresis-free magnetocaloric effect across a wide temperature range. The alloy has high relative cooling power and magnetoresistance, making it suitable for hysteresis-free magnetocaloric applications.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Reena Sharma, Neelam Hooda, Ashima Hooda, Satish Khasa
Summary: A polycrystalline double perovskite La2CoMnO6 sample was prepared and its structural, dielectric and magnetic properties were investigated. The sample exhibited complex structures and magnetic behavior, and showed good conductivity and dielectric performance. Its multi-domain magnetic structure suggests its suitability for memory device applications.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Shubha Dubey, Jisha A. Abraham, Kumud Dubey, Vineet Sahu, Anchit Modi, G. Pagare, N. K. Gaur
Summary: This study investigates the optoelectronic, thermodynamic, thermoelectric, and mechanical stability properties of RhTiP Half Heusler semiconductors. The results show that RhTiP is a non-magnetic material with confirmed mechanical stability. It is found to be an indirect-bandgap semiconductor with a good Seebeck coefficient. This study suggests that RhTiP has promising applications in the thermoelectric and optoelectronic fields.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Xun Xie, Jiong-Ju Hao, Hong-Wei Yang
Summary: This work presents a multilayer film structure that uses optical resonance to prepare highly efficient and saturated red, green, and blue transmittance colors. Numerical simulations and analysis show that the structure can produce R, G, and B colors with a purity comparable to standard RGB colors, while maintaining efficient transmission efficiency and obtaining a rich variety of structural colors. Additionally, a metallic interlayer is introduced to selectively suppress resonances in the short-wavelength region, improving the purity of the red color. The study also investigates the effect of the incidence angle on color purity and transmission efficiency.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Yueqiang Zhao
Summary: Solubility property is of great interest in chemical, physical, pharmaceutical, material, and environmental sciences. Understanding the intrinsic reason behind solubility behavior is a fascinating task. The theoretical relation between binary mutual solubility and liquid-liquid interfacial tension has been derived, where the partitioning of solute molecules between two coexisting liquid phases is determined by the transfer free energy per unit segment for a chain-like solute molecule expressed in terms of solute-solvent interfacial tension. This general theory of solubility is in good agreement with experimental results for binary mutual solubility and molar transfer free energy of solute molecules.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Osama K. M. Bashiar, R. E. Kroon, H. C. Swart, R. A. Harris
Summary: ZnO thin films with near-infrared emission were successfully fabricated using pulsed laser deposition under vacuum conditions, without the need for additional gases or implantation methods. The NIR emission was hypothesized to be caused by defects in the ZnO film due to high energy particle impacts on the sample surface.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
O. Stognei, A. Berezutskii, I. Anisimov, A. Deryabin
Summary: The influence of ZrOn matrix stoichiometry on the electrical and magnetoresistive properties of Fe-Zr-O nanocomposites has been studied. It was found that the magnetoresistive effect is not observed in composites with oxygen lack, while composites with oxygen excess show magnetoresistive effect and increased resistivity. Magnetoresistivity in composites with oxygen lack only appears after heat treatment. These results can be explained by the difference in the density of localized states in the oxide matrix of the composites and the ratio between two types of conductivity.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
Mehmet Bayirli, Aykut Ilgaz, Orhan Zeybek
Summary: The present study aims to understand the relationship between impedance characteristics and fractal behaviors. By producing neat and carbon nanotube doped composite specimens, the researchers investigated the electrical properties and surface heteromorphology using Nyquist plots and fractal analysis.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Physics, Condensed Matter
M. I. Khan, Saddam Hussain, Muhamad Saleem, Fatimah Mohammed Alzahrani, Muhammad Siddique, M. S. Hassan, Allah Ditta Khalid, Munawar Iqbal
Summary: The sol-gel method was used to deposit Ti-doped MAPbBr3 films on FTO-glass substrates with different doping ratios (0%, 4%, and 6%). XRD analysis confirmed the cubic structure of all films, and the 4% Ti-doped film exhibited a large grain size, low band gap energy, and high refractive index. Solar cells fabricated using the 4% Ti-doped MAPbBr3 film showed improved performance in terms of current density, open circuit voltage, fill factor, and efficiency.
PHYSICA B-CONDENSED MATTER
(2024)