Article
Chemistry, Multidisciplinary
Layla Almazroai, Rasha E. El-Mekawy, Rihab Musa, Lina Ali
Summary: Sensitization of TiO2 using dyes shifts its spectrum to the visible region, leading to improved hydrogen production. The sensitized photocatalysts exhibited similar morphology and nanoscale particle size, with increased absorbance in the visible region. The addition of the C2 derivative in Ag/TiO2 significantly enhanced the photocatalytic and sonophotocatalytic rates of hydrogen evolution. Methanol addition inhibited photogenerated electron/hole recombination and increased the rate. The sensitization of metal oxides shows promise in industry for producing clean energy in high quantities.
Article
Chemistry, Multidisciplinary
Rajmoni Basumatary, Dimpul Konwar, Bablu Basumatary, Anjalu Ramchiary
Summary: A novel plasmonic Ag assisted Cu2O-CuO/TiO2 heterojunction photocatalyst was prepared using a facile sol-gel technique. The hybrid photocatalyst exhibited surface plasmon resonance (SPR) and interfacial ternary heterojunctions, which resulted in broad visible light absorption and enhanced photocatalytic degradation of methylene blue (MB) under visible light illumination. This integrated plasmonic-heterojunction photocatalytic system offers a promising avenue for enhancing photocatalytic performance in dye-contaminated water treatment.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2023)
Article
Engineering, Electrical & Electronic
T. N. Ravishankar, G. Banuprakash, M. de O. Vaz
Summary: A novel ternary photocatalyst Ag@TiO2/NiFe2O4 was synthesized and characterized, showing excellent photocatalytic activities and photostability through various analytical methods.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2022)
Article
Green & Sustainable Science & Technology
Sangmo Kang, Jungho Hwang
Summary: This study presents a strategy for fabricating reduced graphene oxide-wrapped Ag/TiO2 nanofibers and demonstrates their efficient CO2 photoreduction performance under visible light.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Engineering, Environmental
Rudzani Ratshiedana, Olayemi Jola Fakayode, Ajay Kumar Mishra, Alex Tawanda Kuvarega
Summary: The study focuses on the impact of silver ion doping on the photocatalytic activity of titanium dioxide for the degradation of tartrazine. Results show that optimal degradation of tartrazine can be achieved with a certain amount of doping, suggesting potential applications for removing similar organic pollutants from water.
JOURNAL OF WATER PROCESS ENGINEERING
(2021)
Article
Chemistry, Multidisciplinary
Weizi Zhang, Xinxin Li, Shaoru Liu, Jianhao Qiu, Jiahuan An, Jianfeng Yao, Songlin Zuo, Bo Zhang, Haian Xia, Changzhi Li
Summary: In this study, Ag/TiO2 materials with different interfacial structures were prepared and used for the photocatalytic conversion of biomass-derived 5-HMF to value-added HMFCA. It was found that low-temperature reduction could enhance the photoinduced charge separation efficiency and the localized surface plasmon resonance effects. The 2.5% Ag/TiO2-LTR showed the highest HMFCA selectivity of 96.7% under visible-light illumination. However, the photocatalytic efficiency decreased significantly when the reduction temperature increased due to the encapsulation of Ag NPs by a thicker TiOx overlay.
Article
Materials Science, Ceramics
Tasmia Nawaz, Muhammad Bilal Tahir, M. Sagir, Khurram Shahzad, Arshid Mahmood Ali, Hussein Alrobei
Summary: The Z-scheme based photocatalyst BiVO4/Ag/NiFe2O4 was prepared using the hydrothermal method, demonstrating excellent photocatalytic performance under visible light irradiation and effective removal of azo dye and phenol.
CERAMICS INTERNATIONAL
(2022)
Article
Engineering, Environmental
Akash N. Ghoti, Ashokrao B. Patil, Satish K. Pardeshi
Summary: Titanium dioxide nano-rods were synthesized using a hydrothermal method, and cadmium sulphide and indium-doped cadmium sulphide quantum dots were sensitized on their surfaces. The material was characterized using various methods, and the results showed that indium doping can improve the photoelectrochemical and photocatalytic properties of the material.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Engineering, Environmental
Xin Yu, Jielin Huang, Jingjing Zhao, Shuaifei Liu, Dandan Xiang, Yanting Tang, Juan Li, Quanhui Guo, Xinqi Ma, Junwei Zhao
Summary: Efficient visible light photocatalytic elimination of pharmaceutical factory wastewater was achieved by introducing hybrid Ag/AgCl nanoparticles into Ti3+ self-doped TiO2 mesocrystals. The Ag/AgCl@Ti3+-TiO2 mesocrystals showed superior performance in degrading tetracycline under visible light, mainly attributed to the continuous attacks of photo-generated holes and radicals on tetracycline molecules.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Environmental Sciences
Zhengyang Chen, Shui Yu, Jianping Liu, Yamei Zhang, Yuchen Wang, Jiangyi Yu, Ming Yuan, Pengchao Zhang, Wen Liu, Jiaoxia Zhang
Summary: The continuous presence of organic pollutants in industrial wastewater poses a significant threat to human health, necessitating urgent and effective treatment. Photocatalytic degradation technology, specifically the use of TiO2 photocatalysts, provides a viable solution for the removal of organic pollutants. However, the limited absorption of visible light by TiO2 hinders its full utilization. To address this issue, the study developed an environmentally friendly synthesis of Ag-coated on micro-wrinkled TiO2-based catalysts, enabling extended absorption of visible light. The synthesized C/F-Ag-TiO2 composite exhibited a significantly lower band gap energy and achieved a remarkable degradation rate under visible light, making it a promising candidate for highly efficient environmental remediation.
ENVIRONMENTAL RESEARCH
(2023)
Article
Chemistry, Physical
Wenhao Wang, Lu Zhang, Zhisong Liu, Yanli Kang, Qiang Chen, Wei Wang, Minmin Liu, Bang-Ce Ye, Feng Yu, Yingchun Li
Summary: In this study, a TiO2-NiFe2O4 heterojunction was synthesized for trimethylamine (TMA) detection. The sensor exhibited a significant response to TMA at high temperature, and the response was further enhanced under white-light irradiation. The researchers explored the enhanced gas-sensing performance of the sensor using density functional theory. This study improves the gas-sensing ability for TMA detection and has potential applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Polymer Science
Byung-Geon Park
Summary: In this study, TiO2 photocatalysts doped with metal ions and nitrogen were prepared using a sol-gel method. The N/Ni/TiO2 showed the highest photocatalytic activity and sterilization efficiency among the samples tested, due to its extended light absorption region and high optical intensity.
Article
Chemistry, Multidisciplinary
N. Pugazhenthiran, S. Murugesan, H. Valdes, M. Selvaraj, P. Sathishkumar, P. G. Smirniotis, S. Anandan, R. V. Mangalaraja
Summary: The study obtained porous anatase TiO2 nanospheres decorated with plasmonic silver nanoparticles, which showed enhanced photocatalytic activity in the removal of antibiotic pollutants. Characterization and toxicity analysis indicated that the oxidation products generated from the process were environmentally benign.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2022)
Article
Chemistry, Physical
Achraf Amir Assadi, Sarra Karoui, Khaled Trabelsi, Anouar Hajjaji, Walid Elfalleh, Achraf Ghorbal, Mounir Maghzaoui, Aymen Amin Assadi
Summary: This study investigates the influence of Ag silver nanoparticles (Ag-NPs) decoration on TiO2 nanotubes (TiO2-NTs) on the photocatalysis of emerging pollutants, such as diclofenac sodium. The obtained Ag-NP/TiO2-NT nanocomposites were characterized, and the photocatalytic degradation mechanism of antibiotics with reactive species was detailed. The Langmuir-Hinshelwood model was used to correlate the experimental results with the optimized catalyst.
Article
Chemistry, Physical
Congyu Wang, Zepeng Rao, Asad Mahmood, Xiao Wang, Yan Wang, Xiaofeng Xie, Jing Sun
Summary: A ternary heterogeneous photocatalyst g-C3N4/Ag-TiO2 was successfully fabricated for the photodegradation of gaseous acetaldehyde, showing 5.8 times higher photocatalytic activity compared to bare TiO2 and a 3.7 times increase in acetaldehyde mineralization efficiency. The improved performance of the ternary system is attributed to enhanced adsorption, light-harvesting capability, and charge separation process.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Artis Linarts, Peter C. Sherrell, Kaspars Malnieks, Amanda V. Ellis, Andris Sutka
Summary: A new paradigm of triboelectric polymers, the triboelectric laminate, is reported, which shows electromechanical response comparable to polyvinylidene difluoride. The response in the laminate arises from aligned dipoles generated by contact electrification. The loose interface between different polymer fibers ensures friction and triboelectric charging.
Article
Pharmacology & Pharmacy
Abhijit Biswas, Maria Maloverjan, Kart Padari, Aare Abroi, Margus Ratsep, Sebastian K. T. S. Warmlander, Juri Jarvet, Astrid Graslund, Vambola Kisand, Runno Lohmus, Margus Pooga
Summary: Cell-penetrating peptides (CPPs) are promising transfection agents for delivering compounds into living cells. The properties of the resulting CPP particles in an aqueous solution depend on the solvent used for dissolving the CPP. Using different methods, such as dynamic light scattering and microscopy, it was found that CPPs dissolved in organic solvents form uniform particles, while those dissolved in water tend to form aggregates and micelles.
Article
Chemistry, Physical
Madis Luesi, Heiki Erikson, Helle -Mai Piirsoo, Jaan Aruvali, Arvo Kikas, Vambola Kisand, Aile Tamm, Kaido Tammeveski
Summary: Galvanic exchange was used to prepare AgPd nanocatalysts. The particle sizes were determined to be 10-20 nm, and the AgPd particles obtained using MP-AES had a larger Ag/Pd ratio compared to those obtained using other ratios. The galvanic exchange process resulted in porous and halfmoon shaped particles. Increasing Pd content led to lower mass activities for oxygen reduction reaction (ORR) despite higher specific activity values on larger particles. A Tafel slope value of -60 mV was observed for all the AgPd catalysts.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Jonas Mart Linge, Heiki Erikson, Peeter Ritslaid, Arvo Kikas, Vambola Kisand, Jaan Aruvali, Jekaterina Kozlova, Aile Tamm, Ave Sarapuu, Kaido Tammeveski
Summary: In this study, MnO2 and multiwalled carbon nanotube (MWCNT) composites decorated with silver were prepared to evaluate their electrocatalytic activity towards the oxygen reduction reaction (ORR). The physicochemical characterisation was done using scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The electrochemical studies revealed that the activity and stability of the composite catalysts depend on the substrate material and the thickness of the silver layer.
Article
Crystallography
Ashish Kumar Singh, Reinis Drunka, Krisjanis Smits, Martins Vanags, Mairis Iesalnieks, Aiga Anna Joksa, Ilmars Blumbergs, Ints Steins
Summary: Lightweight magnesium alloys have advantages over Al alloys but are more susceptible to galvanic corrosion. PEO coatings reinforced by nanoparticles can improve corrosion resistance and mechanical properties. This study investigates the effect of processing time on nanoparticle-reinforced PEO coatings on an AZ31 magnesium alloy.
Article
Chemistry, Physical
Jaana Lilloja, Elo Kibena-Poldsepp, Ave Sarapuu, Anastasiia Konovalova, Maike Kaarik, Jekaterina Kozlova, Paarn Paiste, Arvo Kikas, Alexey Treshchalov, Jaan Aruvali, Andrea Zitolo, Jaan Leis, Aile Tamm, Vambola Kisand, Steven Holdcroft, Kaido Tammeveski
Summary: Transition-metal and nitrogen-doped graphene-like material and carbon nanotube composites are synthesized and utilized as cathode catalysts in anion exchange membrane fuel cells. The materials exhibit similar physicochemical properties and electrocatalytic performances with different yields of HO2- formation. The M-N-Gra/CNT catalysts, especially CoFe-N-Gra/CNT, combined with Aemion+ reinforced anion-exchange membrane, show excellent AEMFC performance comparable to that of Pt/C with a peak power density of 638 mW cm(-2), attributed to the presence of M-Nx sites, carbon-encapsulated transition-metal nanoparticles, and nitrogen-containing moieties.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Electrochemistry
Jaanus Kruusma, Tanel Kaambre, Arvo Tonisoo, Vambola Kisand, Karmen Lust, Enn Lust
Summary: The electrochemical behaviour of Al as a current collector in different electrochemical power sources was investigated using the in situ soft X-ray photoelectron spectroscopy (XPS) method. Physical and electrochemical information about the Al-current-collector RTIL interface soaked in N4111(TFSI) ionic liquid was obtained through cyclic voltammetry, electrochemical impedance spectroscopy, and synchrotron in situ soft XPS methods. The obtained data showed the start of intensive oxidation processes and the electro-oxidation of TFSI- anions.
Article
Chemistry, Physical
Ivar Kuusik, Mati Kook, Rainer Parna, Vambola Kisand
Summary: Ultraviolet photoelectron spectroscopy (UPS) measurements were used to study the electronic binding energies of EMIM-DCA vapor. Density functional theory (DFT), Moller-Plesset perturbation theory (MP2), and many-body perturbation theory calculations (GW) were used to interpret the measured spectra. The results showed that the hybrid DFT functionals, which worked well for other ionic liquid vapors, had shortcomings in the case of EMIM-DCA. MP2 calculation and the quasiparticle GW approach provided a better description of the experimental UPS spectra. Charge distribution analysis revealed a favorable charge transfer from the cation to the anion upon ionization.
Article
Electrochemistry
Ehsan Zarmehri, Ragle Raudsepp, Krisjanis Smits, Tanel Kaambre, Andris Sutka, Can Rustu Yoruk, Dzintars Zacs, Ivar Kruusenberg
Summary: This study investigates the electrocatalytic effect of lead and nitrogen co-doped multi-walled carbon nanotube composite catalyst on the oxygen reduction reaction (ORR) in neutral, acidic, and alkaline media. The successful co-doping and formation of lead nanoparticles were confirmed using various characterization methods. The co-doped MWCNT material demonstrates reasonable electrocatalytic activity in different media, indicating its potential as a superior cathode catalyst for fuel cells.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Kaur Muuli, Rohit Kumar, Marek Mooste, Viktoria Gudkova, Alexey Treshchalov, Helle-Mai Piirsoo, Arvo Kikas, Jaan Aruvaeli, Vambola Kisand, Aile Tamm, Andres Krumme, Prabu Moni, Michaela Wilhelm, Kaido Tammeveski
Summary: The goal of achieving large-scale production of zero-emission vehicles by 2035 is expected to create high demand for electric vehicle (EV) development and availability. However, a major challenge is the limited availability of suitable batteries and battery materials. This study presents an alternative catalyst material, FeCoNi-CNF, made from iron, cobalt, and nickel phthalocyanine tri-doped electrospun carbon nanofibers, which shows promise for use in rechargeable zinc-air batteries (RZAB) due to its affordability and performance. FeCoNi-CNF demonstrated comparable performance to Pt-group metal (PGM)-based catalysts in terms of oxygen reduction and evolution reactions, and it exhibited superior operational durability and longer lifespan in RZAB charge-discharge cycling.
Article
Electrochemistry
Kaur Muuli, Marek Mooste, Srinu Akula, Viktoria Gudkova, Markus Otsus, Arvo Kikas, Jaan Aruvali, Alexey Treshchalov, Vambola Kisand, Aile Tamm, Andres Krumme, Sara Cavaliere, Kaido Tammeveski
Summary: A Pt-free cathode catalyst embedded with cobalt(II) phthalocyanine and iron(II) phthalocyanine compounds was prepared, which showed better electrocatalytic oxygen reduction reaction (ORR) activity. The catalyst exhibited a nanofibrous structure with rough surface texture and contained significant amounts of N, Fe, and Co. The D-MN4-CNF-IL-A catalyst, prepared using ionic liquid as a porogen, displayed the best electrocatalytic activity for O2 electroreduction in 0.5 M H2SO4 electrolyte solution, with an ORR onset potential of 0.83 V and a half-wave potential of 0.71 V vs reversible hydrogen electrode (RHE).
Article
Chemistry, Physical
Liga Avotina, Liga Bikse, Yuri Dekhtyar, Annija Elizabete Goldmane, Gunta Kizane, Aleksei Muhin, Marina Romanova, Krisjanis Smits, Hermanis Sorokins, Aleksandr Vilken, Aleksandrs Zaslavskis
Summary: This study examines the electrical properties and layer quality of field emission microtriodes based on tungsten (W) and silicon dioxide (SiO2) with planar electrode geometry. It is found that the FIB microtriode exhibits higher field emission efficiency compared to the PL microtriode due to its higher local electric field near the cathode.
Article
Materials Science, Multidisciplinary
Liva Germane, Linards Lapcinskis, Mairis Iesalnieks, Andris Sutka
Summary: We have demonstrated a method to significantly enhance the triboelectric charge in the contact-separation of identical PDMS contact layers by three orders of magnitude. This improvement is achieved by functionalizing the PDMS with self-assembled monolayers (SAMs) and combining rough and smooth surfaces. The SAM-modified PDMS exhibits a more stable surface charge compared to pristine PDMS.
MATERIALS ADVANCES
(2023)
Article
Materials Science, Multidisciplinary
Jana Andzane, Mikhail V. Katkov, Krisjanis Buks, Anatolijs Sarakovskis, Krisjanis Smits, Donats Erts
Summary: In this study, N-MWCNTs were synthesized and their magnetoresistance and thermoelectrical properties were systematically investigated. The switching of magnetoresistance from negative to positive values at low temperatures was observed, and the n-type conductance and thermal stability of N-MWCNTs were revealed.
