Article
Nanoscience & Nanotechnology
Bing-Yi Yu, You Xie, Xiu Wu, Yue Gao, Su-Fang Wang, Jian-Min Zhang
Summary: Twin graphene with dual-doping of Al and Y atoms (Y=B, N, O) was studied to understand its structural, electronic, and magnetic properties. The results showed that different doping concentrations and atomic positions significantly affected the electronic and magnetic properties of twin graphene, suggesting potential applications in nanomagnets and spintronics devices.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2021)
Article
Chemistry, Physical
Sergio Conejeros, M. Zamir Othman, Alex Croot, Judy N. Hart, Kane M. O'Donnell, Paul W. May, Neil L. Allan
Summary: This study reports the energetics and electronic properties of Li and N co-doped diamond, with emphasis on the behavior of LiCN4 clusters as potential shallow donors. The results suggest that substitutional Li, when combined with N, may stabilize the LiCN4 cluster to exhibit shallow donor behavior.
Article
Chemistry, Physical
Yuan Li, Yuyi Yang, Kai Li, Yingwu Wang, Ping Ning, Xin Sun
Summary: This study investigated the adsorption and dissociation of H2S on Ni embedded graphene doped with nitrogen atoms. The results showed that N doping enhanced the adsorption interaction and regulated the electronic properties of the supports. Although dissociation reactions were not thermodynamically and kinetically favorable, the study provided valuable information for designing and fabricating long-term sulfur-durable H2S sensors.
CHEMICAL PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Song Lu, Yang Zhang, Mohamed F. Mady, Obinna Egwu Eleri, Wakshum Mekonnen Tucho, Michal Mazur, Ang Li, Fengliu Lou, Minfen Gu, Zhixin Yu
Summary: In this research, a sulfur-doped Ni-N-C catalyst was successfully synthesized through a facile ion-adsorption and pyrolysis treatment. This catalyst showed higher activity and selectivity in electrochemical CO2 reduction (ECR) to CO, along with excellent stability. The synergetic effect between sulfur and Ni-N-X moieties was identified as the key factor contributing to the high activity and selectivity.
Article
Chemistry, Multidisciplinary
Yue Lian, Yujing Zheng, Zhifeng Wang, Yongfeng Hu, Jing Zhao, Huaihao Zhang
Summary: By combining nitrogen-doped and vacancy-defective Nb2O5 with carbon nanotubes, a new microsphere composite material is prepared to improve the ion transport rate and conductivity of niobium pentaoxide in lithium/sodium storage systems. The material shows good electrochemical performance and has potential for practical application.
Article
Chemistry, Multidisciplinary
Siyuan Nie, Wei Shen, Shengnan Shen, Hui Li, Yuanhui Pan, Yuechang Sun, Yinghua Chen, Haiqin Qi
Summary: Phosphorus is considered the best substitutional donor for n-type diamonds, but obtaining n-type diamonds with satisfying properties is challenging due to vacancy-related complexes and other defects in P-doped diamonds. This study used density function theory to examine PV and PVH complexes, revealing the possibility of these complexes emerging when doping a single P atom. The presence of P atoms benefits the formation of PV and PVH complexes, especially on (111) diamond surfaces, and the bond populations of P-C bonds indicate that PVH complexes are more stable than PV complexes.
APPLIED SCIENCES-BASEL
(2021)
Article
Electrochemistry
Jun Huang
Summary: This study presents a field theoretic derivation for the free energy of electrolyte solution, introducing a reference system to describe non-electrostatic interactions between charged particles. By combining classical and quantum mechanical parts, a hybrid density-potential functional for the electric double layer grand canonical potential is obtained. Numerical implementation demonstrates the model's effectiveness, particularly showing oscillating density of counterions near the metal surface when using the FMT for the reference system.
ELECTROCHIMICA ACTA
(2021)
Article
Physics, Condensed Matter
Julian Gebhardt, Christian Elsaesser
Summary: An investigation on two commonly used correction schemes, DFT+U and DFT+1/2 self-energy correction, reveals that they individually fail to provide satisfactory results for describing the electronic structure of strongly correlated metal-oxide semiconductor like NiO. However, when combined, they offer a comprehensive and broadly applicable approach with improved predictive power and computational efficiency compared to traditional density-functional theory methods.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Chemistry, Physical
Yongjun Zhou, Zhe Lu, Jingwei Li, Shifeng Xu, Dan Xu, Bo Wei
Summary: This study investigated the electronic properties and structural stability of Nb-doped LaFeO3 oxide, as well as the adsorption of H-2 molecule on both clean and Nb-doped LFO surfaces through theoretical calculations. The results showed that Nb doping improved electrical conductivity and enhanced structural stability of orthorhombic LFO, providing a theoretical explanation for experimental observations. Additionally, Nb doping slightly enhanced the adsorption of H-2 molecule and facilitated the dissociation of H-2 to H atoms.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Huiyuan Cheng, Zihao Fan, Xuemei Wu, Manman Feng, Wentao Zheng, Guangping Lei, Xiangcun Li, Fujun Cui, Gaohong He
Summary: In this study, tunable Co single-atom catalysts were fabricated and the effect of metal-C coordination on catalyzing CO2 reduction reaction was investigated. The experimental results showed that the CO Faradaic efficiency of the catalysts could be significantly enhanced by adjusting the ratio of metal-N/C sites. Further theoretical calculations revealed that increasing the Co-C coordination ratio could enrich the electron density of Co atoms and promote the adsorption of *COOH.
JOURNAL OF CATALYSIS
(2022)
Article
Multidisciplinary Sciences
Dahvyd Wing, Guy Ohad, Jonah B. Haber, Marina R. Filip, Stephen E. Gant, Jeffrey B. Neaton, Leeor Kronik
Summary: This study presents a simple and inexpensive method to accurately predict fundamental band gaps of crystalline solid-state systems. The method, based on nonempirical optimal tuning of a screened range-separated hybrid functional, has been benchmarked against experiment and found to yield quantitative accuracy across a range of systems.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Nanoscience & Nanotechnology
Vishal Thakur, Narender Kumar, B. Keshav Rao, Mohan L. Verma, Homendra D. Sahu, Swati Verma, Anil Kumar Choubey
Summary: This study investigates the structural and electronic properties of hybrid GR/h-BN 2D sheets doped with two/three/four atomic Graphene/h-BN/BN molecules, using the first principle density functional theory. It is found that weaker atomic bonds are present in hybrid sheets with vacancies, and there are partially ionic and covalent bonds between boron and nitrogen atoms. The energy band-gap of hybrid sheets gradually decreases with increasing vacancy numbers, and with the application of an electric field, the pristine insulating BN sheets are transformed into semiconductors.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2021)
Article
Chemistry, Physical
Meichen Liu, Zhiping Lei, Qingping Ke, Peixin Cui, Jiancheng Wang, Jingchong Yan, Zhanku Li, Hengfu Shui, Shibiao Ren, Zhicai Wang, Ying Kong, Shigang Kang
Summary: This study demonstrates an effective strategy of regulating the electronic structure of oxide electrocatalysts by doping carbon atoms to improve hydrogen evolution activity. By synthesizing TiO2-carbon composites, high HER performance and stability were achieved.
Article
Materials Science, Multidisciplinary
Ling Chen, Cheng Tang, Yao Zheng, Kenneth Davey, Yan Jiao
Summary: Through density functional theory calculations, we designed a triple-single-atom electrocatalyst Ni2Zn/C9N4 for efficient synthesis of urea. This catalyst can convert CO2 and NOx into coupling precursors and facilitate the coupling between precursors to urea via a concurrent N-C-N coupling mechanism. The mechanism enables the direct and selective synthesis of urea while inhibiting competing CO and NH3 formations. Our findings demonstrate the potential of triple-single-atom electrocatalysts in the electrosynthesis of urea and provide insights for the sustainable synthesis of other organonitrogens.
SCIENCE CHINA-MATERIALS
(2023)
Article
Chemistry, Physical
Mohammed Benali Kanoun, Adil Alshoaibi, Souraya Goumri-Said
Summary: In this study, the influence of Cu doping at different concentrations on TiO2 was investigated using density functional theory. The results showed that Cu doping at the Ti site had a lower energy of formation than at the O site in oxygen-rich environments. Cu doping introduced intermediate bands into TiO2, narrowing the band gap and enabling visible light absorption.
Article
Chemistry, Physical
Daire O'Carroll, Jose A. Martinez-Gonzalez, Niall J. English
Summary: Classical molecular dynamic simulations were used to investigate the dynamic properties of water layers on anatase and rutile surfaces. The results showed distinct layering patterns with inhibited molecular motion and enhanced or diminished vibrational modes. This effect appears to be mediated by the coupling of observed layers with under-coordinated surface oxygen atoms and may play a role in the behavior of water at TiO2 interfaces.
MOLECULAR SIMULATION
(2023)
Article
Chemistry, Physical
Hua Wang, Zhaohui Zhou, Run Long, Oleg Prezhdo
Summary: Compared to the bare Fe2O3 (0001) surface, an alpha-Ga2O3 overlayer reduces surface states and suppresses charge recombination, resulting in a cathodic shift in the onset potential for water oxidation.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Ran Shi, Meng Guo, Run Long
Summary: Simulations show that mixing tin and lead in CH3NH3PbI3 can passivate the midgap state created by an interstitial iodine, reduce electron-hole wave functions overlap, and shorten pure-dephasing time. The charge carrier lifetime extends to 3.6 ns due to reduced nonradiative electron-hole recombination, which is longer than other materials. Tin-lead alloying also increases the defect formation energy, effectively enhancing defect tolerance. Overall, this study reveals the factors controlling the enhanced performance of tin-lead mixed perovskite solar cells.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Cheng Cheng, Oleg V. Prezhdo, Run Long, Wei-Hai Fang
Summary: Identifying photolysis and photothermolysis during a photochemical reaction is challenging due to the non-equilibrium and ultrafast nature of the processes. In this study, the authors use advanced ab initio molecular dynamics to investigate the photodissociation of N2O on a TiO2 surface. They establish the detailed mechanism and find that photothermolysis governs the dissociation when N2O- is short-lived, while photolysis becomes dominant as the N2O- resonance lifetime increases. The authors also demonstrate that thermal dissociation of N2O can be achieved by choosing appropriate metal dopants. Overall, this study provides a fundamental understanding of the competition and synergy between photocatalytic and photothermocatalytic dissociation of N2O and has implications for designing high-performance transition-metal oxide catalysts.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Edoardo Mosconi, Asma A. Alothman, Run Long, Waldemar Kaiser, Filippo De Angelis
Summary: Controlling the chemical properties of A-site cations in 2D metal halide perovskites (MHPs) and in 2D/3D assemblies is crucial for stable and efficient optoelectronic devices. This study rationalizes the chemical interactions of different classes of organic cations in 2D MHPs, emphasizing the potential enhancement in stability through hydrogen bonding within the organic framework. This observation may lead to the design of organic cations with stronger intermolecular interactions for increased stability in MHP-based devices.
ACS ENERGY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Hengwei Qiu, Fu Li, Shan He, Ran Shi, Yaoyao Han, Hannikezi Abudukeremu, Lin Zhang, Yan Zhang, Song Wang, Wangyu Liu, Chao Ma, Honghua Fang, Run Long, Kaifeng Wu, Hao Zhang, Jinghong Li
Summary: This study reports the synthesis of uniform, epitaxially grown CsPbBr3/CdS Janus nanocrystal heterostructures with ultrafast charge separation across the electronically coupled interface. Each Janus nanocrystal contains a CdS domain that grows exclusively on a single {220} facet of CsPbBr3 nanocrystals. The promoted charge separation and extraction in epitaxial Janus nanocrystals leads to photoconductors with drastically improved responsivity and detectivity, which is promising for ultrasensitive photodetection.
Article
Materials Science, Multidisciplinary
Cara-Lena Nies, Michael Nolan
Summary: The progress in semiconductor devices driven by Moore's Law is hindered by the limitations of currently used copper interconnects. The search for alternative materials or methods to reduce the volume of diffusion barriers and liners is crucial for future electronic devices.
JOURNAL OF PHYSICS-MATERIALS
(2023)
Article
Chemistry, Physical
Jin Li, Michael Nolan, Christophe Detavernier
Summary: Metal oxide semiconductors are greatly influenced by native defects, making the interpretation of X-ray photoelectron spectroscopy (XPS) results challenging. In this study, a first-principles analysis was conducted on the core-level shift of various crystal imperfections in ZnO. The results suggest that the commonly adopted assignment of XPS defect peaks to the most stable defect (Vo) in ZnO is likely a misinterpretation, and instead, the defect-related peak arises from O-i or specific surface configurations. The misinterpretation of XPS results may lead to erroneous conclusions about material properties.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Mahabir Prasad, Niall J. English, Somendra Nath Chakraborty
Summary: We studied the effect of static electric fields on the hydrogen bond structure and dynamics of TIP4P/2005 water. Electric fields of 0.1 and 0.4 V/nm had no additional effect on the water's changes, while a field of 1.0 V/nm enhanced the slowing down of dynamics and caused crystallization or amorphization. With increased electric fields, H-bonds became stronger, but the asymmetry between donor/acceptor bonds remained.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Mary T. Ajide, Niall J. English
Summary: This study uses non-equilibrium molecular dynamics simulation to investigate the response of water molecules to external electric fields and temperature changes. The results reveal intriguing anomalies in water structure, interaction, dynamics, and hydrogen bond kinetics.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Chemistry, Physical
Ji Liu, Rita Mullins, Hongliang Lu, David Wei Zhang, Michael Nolan
Summary: In this study, first principles density functional theory simulations were used to investigate the atomic-scale reaction mechanism between RuCp2 and CoCp2 precursors and Si substrates with different surface terminations. The results showed that the surface reactivity of CoCp2 is highly dependent on substrate surface terminations, which explains the variations in nucleation delay and growth-per-cycle reported in different studies. On the other hand, RuCp2 is not a suitable precursor for Ru deposition due to highly exothermic ligand elimination reactions on all studied surface terminations.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Ran Shi, Run Long
Summary: Defects like metal vacancies degrade the photoelectric properties of metal halide perovskites by serving as nonradiative recombination centers. Nonadiabatic molecular dynamics revealed that alkali metal dopants significantly enhance the performance of mixed tin-lead perovskites. Alkali dopants raise the formation energy of tin vacancies to 1 eV, resulting in decreased defect concentration. Tin vacancies facilitate the doping of alkali metals into perovskites. These vacancies generate iodine trimers that create midgap states and promote rapid electron-hole recombination. Alkali metal additives eliminate trap states, weaken nonadiabatic coupling, and slow down charge recombination with a coefficient of 5.5 compared to defective tin-lead mixed perovskites. Our research provides a theoretical model for alkali metal passivation at the atomic level, enhancing the defect tolerance of tin-lead mixed perovskites and offering valuable insights for optimizing high-performance perovskites.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Lin Zhang, Hengwei Qiu, Ran Shi, Jinsong Liu, Guangliu Ran, Wenkai Zhang, Genban Sun, Run Long, Weihai Fang
Summary: This work presents the attractive device performance of perovskite photoconductors based on epitaxial CsPbBr3-Pb4S3Br2 Janus nanocrystals. The carrier relaxation and transfer mechanism of the heterojunction is also investigated. The study demonstrates that the photogenerated holes on CsPbBr3 can be efficiently extracted by Pb4S3Br2, leading to long-range charge separation and transport, resulting in exceptional responsivity and specific detectivity.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Hua Wang, Zhaohui Zhou, Run Long, Oleg Prezhdo
Summary: In this study, ab initio quantum dynamics simulations were performed to investigate the effect α-Ga2O3 overlayers on charge recombination in Hematite photoanode. The results showed that the overlayers eliminated surface states and suppressed charge recombination, explaining the observed cathodic shift in the onset potential for water oxidation and increasing charge carrier lifetime. This work advances the understanding of the influence of surface passivation on charge recombination dynamics and provides guidance for designing novel α-Fe2O3 photoanodes.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Ran Shi, Meng Guo, Run Long
Summary: Simulations show that mixing tin with lead in CH3NH3PbI3 can passivate the midgap state created by an interstitial iodine through compressive strain and upshifted valence band maximum, reduce electron-hole wave functions overlap, and shorten pure dephasing time through high-frequency phonon modes. The significantly reduced nonradiative recombination leads to an extended charge carrier lifetime of 3.6 ns, which is an order of magnitude longer than the Ii-containing CH3NH3PbI3, over 2.5 times longer than pristine CH3NH3PbI3, and even 1.7 times longer than tin-lead mixed perovskite without I-i defects. Tin-lead alloying also increases the I-i defect formation energy, effectively enhancing defect tolerance. This study reveals the factors controlling the enhanced performance of tin-lead mixed perovskite solar cells.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)