Article
Environmental Sciences
Mohammad Rezaei Ardani, Fathin Azwina, Tan Yee Wern, Siti Fatihah Ramli, Sheikh Abdul Rezan, Hamidi Abdul Aziz, Abdul Rahman Mohamed
Summary: This study investigated the coagulation performance of titanium tetrachloride (TiCl4) for leachate treatment and preparation of titanium oxide (TiO2) from generated sludge through calcination process. The results showed that TiCl4 and chitosan addition can significantly reduce suspended solids and chemical oxygen demand. The prepared TiO2 exhibited different crystal phases and band gaps at different temperatures.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Article
Chemistry, Multidisciplinary
Si-Ming Wu, Yi-Tian Wang, Shi-Tian Xiao, Yan-Xiang Zhang, Ge Tian, Jiang-Bo Chen, Xiao-Fang Zhao, Christoph Janiak, Menny Shalom, Detlef W. Bahnemann, Li-Ying Wang, Xiao-Yu Yang
Summary: Directed transfer of carriers in semiconductors by structural design is challenging but important. In this study, TiO2 nanosheets with interlayered sp(2) carbon and titanium vacancies were obtained, and the directed transfer of carriers from the excited position to Ti-vacancies to interlayered carbon was observed. This greatly increased the charge transport efficiency and resulted in excellent photocatalytic and photoelectrochemical activity, as well as significant lithium/sodium ion storage performance. Theoretical calculations further revealed the mechanism of spatial inside-out cascade electron transfer.
Article
Chemistry, Inorganic & Nuclear
Alex A. Fertig, Ellen M. Matson
Summary: This study evaluates the efficacy of multiple methods for determining the average bond dissociation free energy (BDFE) of hydroxide moieties in polyoxovanadate clusters. Cyclic voltammetry is used to obtain thermochemical parameters of proton coupled electron transfer (PCET) without the need for synthetic isolation of intermediates. A method involving open circuit potential measurements is found to be most attractive for direct measurement of BDFE and determination of PCET stoichiometry. The driving force of PCET is then linked to the rate constant for hydrogen atom transfer to organic substrates through the Marcus cross relation, enabling rate predictions for multielectron/multiproton transfer reactions.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Sarah Maier, Eric M. Collins, Krishnan Raghavachari
Summary: While accurate wave function theories are computationally intractable for large systems, density functional theory often fails to describe electronic changes in chemical processes. In this study, we propose an efficient Delta ML model that combines molecular fragmentation, systematic error cancellation, and machine learning to achieve coupled cluster accuracy for vertical ionization potentials by correcting for deficiencies in DFT.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Materials Science, Multidisciplinary
Ju Hyeon Jung, Hongjun Oh, Bonggeun Shong
Summary: As semiconductor devices shrink in size, understanding the fabrication processes at the molecular level is becoming more important. This study used computational chemistry methods to investigate the fluorination reactions of TiN, TiO2, and SiO2, and compared their surface reactivity for etching processes. The results showed that HF can etch these materials, producing TiF4 and SiF4 as byproducts. While the etching of TiO2 and SiO2 was suggested to be favorable, the reaction of TiN was thermodynamically hindered. This study provides theoretical insights into the fluorination reactivity of TiN and explores the etching selectivity between different materials, which is crucial for the ALE process conditions of TiN.
Article
Electrochemistry
Savisha Mahalingam, Abreeza Manap, Ramisha Rabeya, Kam Sheng Lau, Chin Hua Chia, Huda Abdullah, Nowshad Amin, Puvaneswaran Chelvanathan
Summary: The goal of this study is to investigate the impact of the chemical treatment of titanium tetrachloride (TiCl4) on graphene quantum dots (GQDs)-based dye-sensitized solar cells (DSSCs). The mechanism of how the TiCl4 treatment provides high surface area and porosity to enhance the adsorption of GQDs and dye is proposed. The electron transport analysis showed that the treatment reduced electron recombination rate and increased electron injection efficiency, resulting in improved performance of the DSSC.
ELECTROCHIMICA ACTA
(2023)
Article
Thermodynamics
Nadia Sebbar, Henning Bockhorn, Dimosthenis Trimis
Summary: This study investigates the similarities in thermochemical properties and oxidation kinetics among various polycyclic aromatic hydrocarbons. The systems considered include benzene (A1), naphthalene (A2), phenanthrene (A3), pyrene (A4), as well as larger molecules such as benzo[ghi]perylene (A6) and coronene (A7). Thermochemical properties, bond energies, and oxidation kinetics are calculated and compared for each system. The results demonstrate strong similarities and redundancies in behavior among these systems, suggesting that reaction paths and kinetic barriers determined for small molecules can be used as estimates for larger aromatic hydrocarbons, reducing computation costs.
COMBUSTION SCIENCE AND TECHNOLOGY
(2023)
Article
Chemistry, Physical
Annabella Selloni, Taehun Lee
Summary: The density and arrangement of oxygen vacancies play a crucial role in tuning the physicochemical properties of TiO2. In this study, we used density functional theory to investigate the geometries and stability of vacancy aggregates in rutile and anatase polymorphs of TiO2. Through extensive exploration, we found that divacancies prefer to align at second-nearest-neighbor trans positions in the same TiO6 octahedron, and ordered chains and planar aggregates of vacancies are energetically favorable over disordered noninteracting vacancies in both polymorphs. However, the energetic gain upon vacancy aggregation is much larger in rutile than anatase. As a result, vacancy complexes are stable at and above typical sample preparation and annealing temperatures in rutile, whereas only one-dimensional chain structures are predicted to survive at those temperatures in anatase.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Applied
Carlos Rafael Silva de Oliveira, Marcos Antonio Batistella, Selene Maria de Arruda Guelli Ulson de Souza, Antonio Augusto Ulson de Souza
Summary: In this study, an eco-responsible flame retardant treatment based on kaolinite-TiO2 nano-hybrid composite was successfully prepared and incorporated into cotton fabric fibers through a more sustainable route. The treated cotton product showed high fireproof performance, thermal degradation reduction, residue formation increase, and peak heat release reduction, all while maintaining mechanical resistance and some resistance to washing.
CARBOHYDRATE POLYMERS
(2021)
Article
Energy & Fuels
Xin Bai, Yang Li, Shuyuan Liu, Ruining He, Jinhu Liang, Geyuan Yin, Shijie Zheng, Yan Qian, Xuebin Wang
Summary: To eliminate NOx emissions, the recovery and incineration of DMF vapor in the exhaust gas is necessary, which also provides heat for the production process. This study systematically investigated the 16 H-atom abstraction reactions of DMF for its ignition control in fuel-lean combustion. The results show that the abstraction of H-atom from the aldehyde group is dominant, and the fastest rates are produced by OH, Ḣ, and CH3 O abstractors. A detailed kinetic model of DMF was developed based on the calculation results, accurately predicting the ignition delay times at different temperatures and equivalence ratios.
Article
Chemistry, Physical
Shideng Yuan, Shasha Liu, Xueyu Wang, Heng Zhang, Shiling Yuan
Summary: In this work, a multiscale and comprehensive study was conducted to investigate the heterogeneous interaction between H2O2 and TiO2 particles. The adsorption of H2O2 and H2O on the TiO2 surface was found to be primarily determined by the weaker interaction between Ti and O atoms. The adsorption energy was dominated by electrostatic effect, and the adsorption energy of TiO2-H2O complexes was lower than that of TiO2-H2O2 ones. H2O2 and H2O interacted with TiO2 particles through molecular adsorption and dissociation, resulting in surface modification and Ti-OH formation. The uptake of H2O2 on TiO2 surface was suppressed with increasing humidity, possibly due to competition for surface sites with H2O.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Thermodynamics
Denis A. Knyazkov, Andrey V. Cherepanov, Vitaly G. Kiselev, Ilya E. Gerasimov, Tina Kasper, Andrey G. Shmakov
Summary: Understanding the ion chemistry in flames is crucial for developing ion sensitive technologies for controlling combustion processes. In this work, the spatial distributions of positive ions in premixed flames of ethylene/oxygen/argon mixtures were measured. A flame sampling molecular beam system coupled with a mass spectrometer was used for the measurement. An updated ion chemistry model was proposed and validated against the experimental profiles. The model was found to reproduce the measured relative abundance of key oxygenated cations but underpredicts the abundance of C3H3+ under fuel-rich conditions. Several aromatic and cyclic cations dominating under fuel-rich conditions were identified.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Engineering, Electrical & Electronic
Kai Ti Low, Fong Kwong Yam, Khi Poay Beh, Asrulnizam Abd Manaf, Khi Khim Beh
Summary: In this study, TiO2 nanoparticles were synthesized using a modified sol-gel method and showed significant reduction in particle size. A UV photodetector fabricated from TiO2 on an FR-4 board demonstrated remarkable stability, high sensitivity, and potential application in UV photodetection domain. The photodetector exhibited high sensitivity and responsivity under UV-A illumination, with optimum operating potential at a bias of 3 V.
SENSORS AND ACTUATORS A-PHYSICAL
(2021)
Article
Engineering, Chemical
Yuqian Zhang, Zhizhong Dong, Gang Xiong, Stephen D. Tse
Summary: Tungsten-doped titanium-dioxide nanoparticles are synthesized using a multiple-diffusion-flame burner, showing the effect of tungsten doping on the structure and properties of the nanoparticles. It is found that doping enhances the absorption ability of visible light.
Article
Chemistry, Physical
Mohamed Anwar Ismail, Mohamed N. Hedhili, Dalaver H. Anjum, Venkatesh Singaravelu, Suk Ho Chung
Summary: Iron-doped titanium dioxide nanoparticles were synthesized by flame spray pyrolysis, promoting the formation of rutile phase and exhibiting catalytic degradation of dyes effect under visible light.
Article
Thermodynamics
Simon D. Rihm, Jethro Akroyd, Markus Kraft
Summary: A fully-elementary reversible kinetic model for electrocatalytic CO2 reduction has been established and verified, including hypothesized reaction paths and intermediates. The model successfully captures trends observed in experimental data and challenges the widely accepted hypothesis of dimerization via *CO intermediates.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Chemistry, Multidisciplinary
Angiras Menon, Laura Pascazio, Daniel Nurkowski, Feroz Farazi, Sebastian Mosbach, Jethro Akroyd, Markus Kraft
Summary: A new OntoPESScan ontology is developed for the semantic representation of one-dimensional potential energy surface (PES) scans in computational chemistry, following knowledge graph principles and The World Avatar (TWA) project. OntoPESScan is linked to other chemistry ontologies in TWA, such as OntoSpecies and OntoCompChem, to uniquely identify species along the PES and associate potential energy surfaces with quantum chemical calculations. Additionally, a force-field fitting agent is developed using the OntoPESScan ontology to fit force fields to reactive surfaces on the fly.
Article
Environmental Studies
Zhongming Shi, Heidi Silvennoinen, Arkadiusz Chadzynski, Aurel von Richthofen, Markus Kraft, Stephen Cairns, Pieter Herthogs
Summary: This paper develops a methodology to quantitatively define the characteristics of mixed-use developments and applies it in Singapore. The study shows how these defined archetypes can provide more detailed data for urban building energy modelling, with potential for automation of the workflow in the future.
ENVIRONMENT AND PLANNING B-URBAN ANALYTICS AND CITY SCIENCE
(2023)
Article
Engineering, Chemical
Simon D. Rihm, Jiaru Bai, Laura Pascazio, Markus Kraft
Summary: Automating the creation and calibration of microkinetic models allows for detailed analysis of reaction mechanisms and multi-scale modeling of reactors based on ab initio calculations. The example of electrochemical CO2 reduction demonstrates the need for a structured and standardized representation of concepts across different scales. Significant progress has been made in this area through dynamic knowledge graphs, with partial successes in mechanism generation, quantum mechanical calculations, and calibration with experimental data.
CHEMIE INGENIEUR TECHNIK
(2023)
Article
Thermodynamics
Yong Ren Tan, Yichen Zong, Maurin Salamanca, Jacob W. Martin, Jochen A. H. Dreyer, Jethro Akroyd, Wenming Yang, Markus Kraft
Summary: A novel modified coflow burner was developed to inject charge from a non-thermal plasma into helium-diluted ethylene flames. Different frequencies of the high voltage signal were used to control the ion concentration injected into the flames. Optical emission spectroscopy and other measurements were conducted to study the effect of charge injection on soot reduction in the flames. The results showed that the system is a promising candidate for studying the charge effect from non-thermal plasma on soot formation in laminar coflow diffusion flames.
COMBUSTION SCIENCE AND TECHNOLOGY
(2023)
Article
Chemistry, Physical
Yuan Sheng, Manoel Manuputty, Markus Kraft, Rong Xu
Summary: NiFe phosphide (NiFe-P) is synthesized through flame aerosol synthesis (FAS) method, with controlled coformation of carbon, resulting in the selective synthesis of interlaced NiFe-P nanoplates and < 5 nm NiFe-P nanoparticles. During the oxygen evolution reaction (OER), NiFe-P transforms into highly active (oxy)hydroxides by surface oxidation and dephosphorylation. The optimal film shows high durability, with a slight structural instability induced by the electrochemical removal of carbon promoting a self-refreshing mechanism that helps maintain stable surface Fe content and enhances durability.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Urban Studies
Heidi Silvennoinen, Arkadiusz Chadzynski, Feroz Farazi, Ayda Grisiute, Zhongming Shi, Aurel von Richthofen, Stephen Cairns, Markus Kraft, Martin Raubal, Pieter Herthogs
Summary: This paper introduces a method using an ontology to represent the relationships between zoning types, land uses, and programs in Singapore. The ontology is linked to geospatial data stored in a knowledge graph, enabling multi-domain queries on urban data. The study demonstrates how a semantic web-based approach can enhance access and usability of land use regulation data, particularly for site selection and exploration. Additionally, the paper discusses the challenges of defining concepts in the land use regulation field and the potential of linking OntoZoning to a broader semantic web-based urban planning regulatory framework.
JOURNAL OF URBAN MANAGEMENT
(2023)
Article
Environmental Sciences
Mutian Ma, Laura-Helena Rivellini, Nethmi Kasthuriarachchi, Qiren Zhu, Yichen Zong, Wenbin Yu, Wenming Yang, Markus Kraft, Alex K. Y. Lee
Summary: Laboratory study shows that the application of PODE3-diesel blended fuel can significantly reduce organic aerosols and black carbon emissions from diesel engines. P20 blended fuel has the highest reduction in total particulate matter mass. This study also reveals the changes in the functionality of soot surface/nanostructure caused by PODE3 and how it affects the mixing state of black carbon and organic aerosols in diesel engine exhaust.
ATMOSPHERIC ENVIRONMENT-X
(2023)
Article
Engineering, Chemical
Chi Hung Vo, Nishu Goyal, Markus Kraft, Iftekhar A. Karimi
Summary: Methanococcus maripaludis can use CO2 as the sole carbon source. The study found that N2 is a better nitrogen source for carbon conversion to CH4 in M. maripaludis. The revised metabolic model iMR557 was able to successfully replicate acetate dissimilation and provide insights into flux distributions under different conditions.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Green & Sustainable Science & Technology
John Atherton, Markus Hofmeister, Sebastian Mosbach, Jethro Akroyd, Feroz Farazi, Markus Kraft
Summary: The expansion of variable renewable energy (VRE) generation presents challenges for national energy systems, as coal energy generation maintains and grows its position in the imbalance market. A comparative study of the British and German markets reveals changing roles of VRE, fossil fuelled energy, and compensation technologies.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2023)
Article
Chemistry, Physical
Xiaochun Hu, Qianwenhao Fan, Mingwu Tan, Yuqing Luo, Xianyue Wu, Manoel Y. Manuputty, Jie Ding, Tej S. Choksi, Markus Kraft, Rong Xu, Zhiqiang Sun, Wen Liu
Summary: The surface properties of oxidic supports and their interaction with the supported metals play critical roles in governing the catalytic activities of oxide-supported metal catalysts. The dynamic behavior of Au nanocatalysts supported on flame-synthesized TiO2 was systematically investigated, revealing a negative correlation between the catalytic activity of Au/TiO2 and the oxygen vacancy at the Au/TiO2 interface. The transfer of electrons from TiO2 to Au, facilitated by interfacial oxygen vacancies (Vo), is the main factor responsible for the low catalytic activity observed in Vo-rich Au/TiO2 catalysts, which consequently leads to the suppression of CO oxidation.
Article
Engineering, Electrical & Electronic
Tengpeng Chen, He Ren, Yuhao Sun, Markus Kraft, Gehan A. J. Amaratunga
Summary: This paper proposes a new method for optimal phasor measurement unit (PMU) placement (OPP) in smart grids. It considers the effects of conventional measurements, limited channels of PMUs, zero-injection buses (ZIBs), single PMU loss contingency, state estimation error (SEE), and the maximum SEE variance (MSEEV). A robust t-distribution maximum likelihood estimator (MLE) is used to obtain SEE and MSEEV, allowing for modeling of both Gaussian and non-Gaussian noises. The proposed OPP method is verified through simulations on various power systems.
JOURNAL OF MODERN POWER SYSTEMS AND CLEAN ENERGY
(2023)
Article
Public Administration
Hou Yee Quek, Franziska Sielker, Jethro Akroyd, Amit N. Bhave, Aurel von Richthofen, Pieter Herthogs, Claudia van der Laag Yamu, Li Wan, Timea Nochta, Gemma Burgess, Mei Qi Lim, Sebastian Mosbach, Markus Kraft
Summary: This paper discusses city digital twins based on two digital integration methodologies-systems and semantic integration, bringing together experiences from five research projects. The nature of underlying technologies and their implications for interoperability and compatibility in planning processes and smart urbanism are revisited. Semantic approaches offer new opportunities for bidirectional data flows to inform governance processes and technological systems for co-creation, cross-pollination, and optimal outcomes. This article suggests considering the technological dimension as a new addition to the trifecta of economic, environmental, and social sustainability goals for guiding planning processes to address the conundrum of fragmentation, interoperability, and compatibility.
Article
Chemistry, Multidisciplinary
Simon D. Rihm, Mikhail K. Kovalev, Alexei A. Lapkin, Joel W. Ager, Markus Kraft
Summary: Utilising CO2 to synthesise chemicals through electrocatalysis has potential for energy storage and decarbonisation. Copper-based electrodes enable high conversion rates, but our incomplete understanding of reaction paths hampers catalyst design. Here, we identify ten new minor products of CO2 reduction and propose two distinct reaction paths based on selectivity trends. This study contributes to the comprehension of electrocatalytic CO2 reduction mechanisms and calls for further exploration of minor products and reaction conditions.
ENERGY & ENVIRONMENTAL SCIENCE
(2023)
Article
Computer Science, Theory & Methods
Jiaru Bai, Kok Foong Lee, Markus Hofmeister, Sebastian Mosbach, Jethro Akroyd, Markus Kraft
Summary: This work develops a framework to annotate how information can be derived from others in a dynamic knowledge graph. It encodes this using the notion of a derivation and captures its metadata with a lightweight ontology. The framework provides an agent template for monitoring and standardizing the process, and implements synchronous and asynchronous communication modes for agents interacting with the knowledge graph. It is applied in the context of smart cities and demonstrates the ability to handle sequential events across different timescales.
FUTURE GENERATION COMPUTER SYSTEMS-THE INTERNATIONAL JOURNAL OF ESCIENCE
(2024)
