Symposium CI
Advances in Functional Materials for Energy Harvesting, Storage and Solar Fuels
ABSTRACTS
Session CI-1 Innovative nano- and heterostructured functional materials for renewable energy applications
CI-1:IL01 Advanced Nanostructures for Solar Photocatalytic and Photoelectrochemical Fuel Generation and Related Applications
O.K. VARGHESE, Department of Physics & Texas Center for Superconductivity, University of Houston, Houston, TX, USA
Transitioning to an energy system based on renewable electricity and fuels has been recognized as a key strategy toward achieving sustainable development. Among the fuel generation strategies, water splitting and carbon dioxide reduction using solar energy are the most prominent. There have also been efforts to accomplish efficient solar conversion of methane to hydrogen. Compared to other technologies, solar photocatalytic and photoelectrochemical processes facilitate direct conversion of sunlight to fuels, without involving integration of multiple technologies or high temperatures. These processes use semiconductors as photocatalysts to absorb sunlight and perform redox processes. Developing nano-architectures, especially quantum materials and heterostructures, has become a principal strategy to advance the field, as such materials could display scientifically fascinating properties. We were successful in developing new nanostructures of functional materials, highly promising for fuel generation from water, carbon dioxide and/or methane. Additionally, environment-dependent electrical properties of such materials were exploited to develop detectors for hydrogen, an indirect greenhouse gas requiring leak monitoring. This presentation provides the details of our work.
CI-1:IL02 Enhancing the Functional Properties of Powder Aerosol Deposited Ferroelectric Films for Vibrational Energy Harvesting
K.G. WEBBER, M. KUHFUß, Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
The deposition of functional ceramic films is important for numerous applications, such as medical, defense, transportation, and telecommunications. Traditionally, such films are deposited using methods that require high thermal fields. In contrast, powder aerosol deposition (PAD) is a room temperature film deposition method that uses the high kinetic energy of aerosol ejected through a nozzle. The discharged particles impact a substrate at high velocity, where they fracture and consolidate into a dense ceramic film. This method can also be applied to glasses, metals, polymers, and semi-conductors, allowing for the material combinations not possible with higher temperature methods. In particular, thick films >100µm can be rapidly deposited, which is attractive for piezoelectric energy harvesting. Despite the potential, there are drawbacks limiting commercial use, such as nanograins, internal residual stresses, and electrical conductivity. In this presentation, PAD will be discussed in detail, in addition to ongoing research to understand the deposition mechanism and the origins of the internal stress and electrical conductivity. Here, the influence of these effects on the functional properties and methods to enhance the electromechanical response will be presented.
CI-1:IL03 Interface Engineering for All-Solid-State Batteries
TAESEUP SONG1,2, UNGYU PAIK1, SEUNCHEOL MYEONG1, SEUNGWOO LEE1, HYUNGJUN LEE1, JOONHYEOK PARK1, INSUNG HWANG1, JIWOON KIM1, GANGGYU LEE1, MINSUNG KIM1, SEUNGMIN HAN1, JOOHEON SUN1, JUN LIM2, BOGEUM CHOI2, 1Department of Energy Engineering, Hanyang University, Republic of Korea; 2Department of Battery Engineering, Hanyang University, Republic of Korea
All-solid-state batteries (ASSBs) incorporating sulfide-based solid electrolytes with high ionic conductivity are recognized as the next-generation energy storage systems, offering superior safety and energy density through the use of metallic anodes. However, its practical deployment is challenged by various interfacial issues, including contact loss during cycling, which accelerates the growth of Li dendrites, as well as the chemical instability between Li and sulfide-based solid electrolytes. In this study, we first examine the key degradation mechanisms of ASSBs from both electrochemical and mechanical standpoints. We then present our approaches to enhancing the stability of the electrode/solid electrolyte interface. The designed ASSBs effectively inhibit Li dendrite formation and mitigate undesirable side reactions, resulting in significantly enhanced electrochemical performance.
CI-1:IL05 Corrosion-Resistant MoO3/Fe2O3/MoS2 Heterojunctions Stabilize OH– Adsorption for Efficient Light-Assisted Seawater Electrooxidation
WEI TAO, BYUNGCHAN HAN, Department of Chemical & Biomolecular Engineering Yonsei University, Seoul, Korea
Direct seawater electrolysis holds promise for sustainable hydrogen production, yet challenges such as severe chlorine corrosion on the anode and high energy barriers for oxygen evolution reaction (OER) limit its operational time and efficiency. Herein, we present MoO3/Fe2O3/MoS2 heterojunctions to mitigate chlorine-induced corrosion and achieve effective photoelectric synergy. The in situ leached MoO42– and SO42– inhibitors reduce Cl– adsorption, thereby ensuring high OER selectivity, while the MoO3/Fe2O3/MoS2 balances the repelling effects of these inhibitors, facilitating OH– adsorption and widening the overpotential gap between water oxidation and chlorine oxidation. The MoO3/Fe2O3/MoS2 catalyst outperforms its Fe2O3 counterpart in terms of lifespan, maintaining stability at 100 and 300 mA cm–2 for 100 and 500 h, respectively. Additionally, built-in electric fields formed at the interfaces lower interfacial resistance and extend the lifetime of photogenerated carriers by 1.47-fold, allowing for a 20.4% increase in seawater OER current density under light irradiation. Our findings offer a viable strategy for designing high-performance electrocatalysts for light-assisted seawater electrolysis.
CI-1:IL06 Nanostructured Oxides for Photochemical and Electrochemical Functions
TOHRU SEKINO1, DO HYNG HAN1, YOSHIFUMI KONDO1, YEONGJUN SEO1, HISATAKA NISHIDA1, TOMOYO GOTO1,2, 1SANKEN, The University of Osaka, Ibaraki, Osaka, Japan; 2Nara Institute of Science and Technology, Ikoma, Nara, Japan
Nanostructured oxides designed at low-dimensional structure and crystal- and surface-engineering have attracted attention due to synergy of chemical and physical properties. In this study, low-dimensional nanostructured titania/titanate have been developed by modification of the crystal and surface structures. Peroxo-groups modified titania nanotubes (PTNT) were synthesized via chemical treatment of titania nanotubes and direct solution chemical synthesis route that exhibited excellent visible light photocatalytic responsibility [1-3]. PTNT was found to possess selective photocatalytic degradation of organic molecules [4]. Further doping of transition metals realized enhanced photoinduced chemical reactions, suggesting advantages for energy and environmental application. Furthermore, investigation of electrochemical properties of these nanotubular titanate suggested that they were potential candidates for secondary battery active materials. Design strategies, processing, nanostructural features and physical-photochemical functions will be discussed.
[1] ACS Applied Nano Materials, 3(8), 7795–7803 (2020); [2] Discover Materials, 4, 67 (2024); [3] Inorganic Chemistry, 2025. DOI:10.1021/acs.inorgchem.5c03709; [4] Nanomaterials, 14, 1170 (2024).
CI-1:L07 Fundamentals of Electrochemical Charging of MAX Phases and their Hydrogen Storage Potential
R. MIYAR1, A.C. MILES1, M. PRABHAKAR1, G. DEHM1, M. SOKOL2, Y. JOSHI1, B. RATZKER1, M.J. DUARTE1, 1Max-Planck-Institute for Sustainable Materials (MPI-SusMat), Düsseldorf, Germany; 2Department of Material Science and Engineering, Tel-Aviv University (TAU), Tel-Aviv, Israel
Hydrogen storage remains one of the main challenges in the transition to renewable energy systems, as current storage methods face significant limitations in scalability, safety, and efficiency. Mn+1AXn phases are a class of nanolaminated, hexagonal materials composed of an early transition metal (M), an A-group element (A), and carbon/nitrogen (X). Theoretical studies have proposed them as prospective candidates for solid-state hydrogen storage, due to their unique atomically layered structure. This laminated structure provides favorable hydrogen trapping sites, such as interstitial spaces within the M-A layers, potentially allowing them to reliably store and release hydrogen under mild conditions. While said studies have highlighted these capabilities, experimental verification remains limited, with a few studies focusing only on gas-phase hydrogenation. Electrochemical hydrogen charging presents an attractive alternative, enabling solid-state storage at room temperature and ambient pressure. Herein, we present the first systematic investigation of electrochemical hydrogen charging and desorption in MAX phases, comparing Ti2AlC and Ti3AlC2. Hydrogen trapping behavior and desorption mechanisms were examined.
CI-1:L08 Enhanced Electrochemical Properties with Adequate Energy Density in La0.85Ag0.15Mn1-xNixO3 Manganite-based Electrode for Supercapacitor
P. BISWAS, M. KAR, Department of Physics, IIT Patna, Bihta, Bihar
The existence of both electronic and ionic conductivity in a double-modified (Ag and Ni) manganite-based material due to the presence of mixed valency of metal ions and oxygen off-stoichiometry makes them a promising electrode to boost pseudocapacitance behaviour in a supercapacitor. Hence, it has become a centre of attraction for technologies and academic researchers. For this, Ni-doped La0.85Ag0.15Mn1-xNixO3 (x = 0.02-0.15) perovskite materials are successfully synthesised to explore their redox property to understand their use as an electrode material for a supercapacitor. As high as specific capacitance of 450 F/g at 5 mV/s h has been observed from cyclic voltammetry (CV), which can be explained by modelling the chemical networks and microstructure of the Ni modified Lanthanum-Silver Manganites.Low charge transfer resistance (Rct) and series resistance (Rs) are revealed via EIS analysis. Over a broad potential window, a symmetric supercapacitor provides an energy density of 30 Wh/kg and a power density of 900 W/kg, approximately, maintaining 91% of its capacitance after 10,000 cycles. The present study reveals that Ni-doped La-Ag manganites are potential materials for energy storage applications in supercapacitors.
CI-1:IL10 Synthesis of Vanadium Oxides and Their Applications as Gas Sensors with Unique "Response Behavior Selectivity"
SHU YIN, IMRAM, Tohoku University, Sendai, Miyagi, Japan
Conventional semiconductor gas sensors, which operate on the principle of "response-intensity selectivity," face significant challenges in discriminating between gases with similar properties and often require complex multi-channel setups for multi-gas detection, thereby hindering device miniaturization and low-power operation. Here, we propose a novel “response behavior selectivity” gas-sensing concept, in which the gas identification is based on the directionality (i.e., upward or downward) of the response signal. In the case of the monoclinic phase of vanadium oxide VO2(M1), it showed an upward response to ammonia (NH₃) and a downward response to hydrogen sulfide (H₂S), enabling highly selective identification within a mixed-gas environment using a single material and a single channel. The sensor works at room temperature, offering promising potential for applications in healthcare devices, such as smart diapers capable of distinguishing between urination and defecation. The potential for inversion of response direction was evaluated using dopants such as W, Mo, and Cr, which were experimentally confirmed to change the sensing behavior of VO₂(M1). We hope these findings will serve as a foundation for further exploration and theoretical development in the field of gas sensing.
CI-1:IL11 Molecular Tools for Controlling the Size, Size Distribution and Alloy Formation in Metal Nanoparticle Systems
B.L.V. PRASAD, Centre for Nano and Soft Matter Sciences, Bengaluru, India
Surface modification of nanoparticle (NPs) is an important area of research that has great significance in terms of imparting stability to NPs in diverse solvent media. It also defines the way nanoparticles (NPs) interact either with themselves or with the surrounding environment. In general, organic molecules/ligands which have at least one functional group are known to play a key role in modulating many characteristics of NPs viz. controlling their size, morphology and their dispersional stability in a given solvent medium. In this talk we will introduce “Digestive Ripening” (DR), a post-synthetic size modification process as a reliable and reproducible method offering great control over size and size distribution of NPs. DR is known for converting a polydisperse NP system to nearly monodisperse NPs with the help of such organic molecules/ligands. Our systematic work in this area unraveled that the final size distribution of NPs obtained by DR crucially depends on the ligand chain length, the ligand head group-NP binding strength, the ligand-solvent compatibility etc. Recently we also could show that DR could be effectively used to make alloy NPs from a physical mixture of NP dispersions. The specific details of the above mentioned parameters will be discussed during the talk.
CI-1:IL12 Unique ALD/MLD-Enabled Material Functions
M. KARPPINEN, Department of Chemistry and Materials Science, Aalto University, Espoo, Finland
The state-of-the-art gas-phase ALD (atomic layer deposition) and MLD (molecular layer deposition) thin-film techniques allow us to fabricate functional materials that may not be readily accessible through any other fabrication route. The thus realized materials and material families include: (i) metastable polymorphs of simple binary metal oxides such as hard-ferromagnetic ε-Fe2O3, (ii) novel under-bonded or intercalation-type MOF (metal-organic framework) structures e.g. for Li-organic battery application, and (iii) on-demand tailored multilayer/superlattice structures in which either ultra-thin organic layers or atomically dispersed platinum layers are introduced between nm-scale metal oxide layers to e.g. enhance mechanical flexibility, provide carrier doping, block phonon conduction, bring catalytic activity or provide photo-switching functionality for applications ranging from thermoelectrics to photosynthesis. In this presentation, I will discuss exciting examples of properties/functions already demonstrated for these materials and their application possibilities. An intriguing bonus of our microelectronics-compatible ALD/MLD fabrication approach is that it yields the materials in large-area homogeneous and conformal thin-film form, even on demanding surfaces.
CI-1:IL14 Sintering and Intergranular Chemistry inside Metal Oxide Nanoparticle Powder Compacts
O. DIWALD, K. AICHER, T. SCHWAB, G. ZICKLER, Department Chemistry and Physics of Materials, Paris-Lodron Universität Salzburg, Salzburg, Austria
Composite metal oxide nanoparticles are typically far off their thermodynamic equilibrium state. They represent a versatile but so far overlooked source material for the intergranular solid-state chemistry inside ceramics. We explored the potential of vapor phase-grown MgO nanoparticles hosting Ba2+, In3+ and Fe3+ admixtures as precursors for engineered intergranular regions.[1,2] Admixed Ba2+ ions, either isolated or as nanocrystalline BaO segregates that decorate the inner pore walls give rise to bright and characteristic photoluminescence emissions in the visible light range.[1] Moreover, we demonstrated how Fe3+ and In3+ ion admixture to MgO nanoparticles can be used to engage ion exsolution and phase separation, inside the network of diamagnetic and insulating MgO grains.[2] Extremely high uniformity in the distribution of intergranular ferrimagnetic MgFe2O4 films and grains with resulting magnetic coercivity values is achieved. Moreover, percolating networks of semiconducting MgIn2O4 are derived from In3+ admixtures to MgO and gives rise to a dc conductivity enhancement by more than five orders of magnitude.
[1] Schwab T. et al.; Appl. Mater. Interfaces 13 (2021) 25493; DOI: 10.1021/acsami.1c02931; [2] Aicher K., Schwab, T. et al. Small Methods 9, (2025) 240071. DOI: 10.1002/smtd.202400715.
CI-1:L15 Mechanical Deformability for Next Generation Li-ion Batteries
JEONG GON SON, Korea Institute of Science & Technology, Seoul, South Korea
Mechanical stretchability in next-generation batteries not only can realize stretchable energy storage devices but also can cope with volume changes during charging and discharging, greatly increasing long-term stability. Our research team developed an inwardly curved framework for lithium-ion battery electrodes for a stretchable battery with structural stretchability, and all components inherently stretchable and printable lithium-ion battery for free-form construction. In this presentation, we introduce a fully stretchable lithium-ion battery system for free-form configurations in which all components, including electrodes, current collectors, separators, and encapsulants, are intrinsically stretchable and printable. The stretchable electrode acquires intrinsic stretchability and improved interfacial adhesion with the active materials via functionalized organogel as a stretchable binder and separator. Intrinsically stretchable current collectors are fabricated in the form of nanocomposites consisting of a matrix with excellent barrier properties without swelling in organic electrolytes, and nanostructure-controlled multimodal conductive fillers. Finally, our stretchable battery printed on the stretch fabric also exhibits high performance and stretch/long-term stability.
CI-1:L16 Effect of Cold Sintering Process on the High-Rate Performance of V2O5 Cathodes for Lithium-ion Batteries
SEUNGMI LEE1, YOSHIFUMI KONDO1, YASUYUKI KONDO1, YEONGJUN SEO1, TOMOYO GOTO1,2, TOM SCHNEIDER3, YUKI YAMADA1, SANJAY MATHUR3, TOHRU SEKINO1, 1SANKEN, The University of Osaka, Ibaraki, Osaka, Japan; 2Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Nara, Japan; 3Institute of Inorganic and Materials Chemistry, University of Cologne, Cologne, Germany
Vanadium pentoxide (V2O5) is a promising cathode material for lithium-ion battery owing to its high theoretical capacity (294 mAh g-1), low cost, and abundance. However, its low ionic diffusivity and poor electronic conductivity hinder practical application. In this study, to address these issues, a V2O5 cathode was fabricated using the cold sintering process (CSP), a low-temperature densification method (<300 °C) based on the dissolution-precipitation mechanism under hydrothermal-like conditions. CSP is a low-temperature process that can introduce amorphous phases into dense structures, which is expected to improve ionic diffusion and electrical conductivity. The CSP-treated electrodes (CSP-V2O5) exhibited high-rate performance with 75.4% capacity retention at 1 C, greatly surpassing the dry-pressed V2O5 electrodes. Based on structure observations and electrochemical measurements, CSP-induced densification and mixed-valence state enhanced lithium-ion diffusion and electronic conduction. These results demonstrate that CSP provides a scalable and practical strategy for next-generation high-power lithium-ion battery cathodes with superior performance.
CI-1:IL17 Piezoelectricity, Piezoresitivity and Piezocapacity in Pyroproteins and ZnO Tetrapods Heterostructures for Smart Materials
L. VALENTINI, Department of Civil and Environmental Engineering, University of Perugia, Perugia, Italy
Twenty years have passed since Novoselov and Geim published the paper 'Electric field effect in atomically thin carbon films' in Science, and despite billions of dollars of investment, graphene remains one of the most exciting research fields with a market of US$1.5 billion by 2027, but much of this research remains confined to laboratories. The discovery that a new 2D crystalline phase (β-sheet) of self-assembled protein on vdW solids mimics the structure of 2D nanomaterials, opens the possibility of using these bio-inspired materials in place of graphene. β-sheet-rich proteins such as worm silk after thermal treatment form aromatic molecules, which may stack to form a lamellar plastic phase e. g. pyroprotein (PyP). Moreover, three-dimensional PyP assembly, built from interconnected tubular tetrapods, is still unexplored behind their 2D dimensional in terms of electrical properties. Here we report the synthesis and multifunctional properties of 2D pyroprotein-based materials. A 3D PyP structure has been also realized in combination with ZnO tetrapods (ZnO-TPs) and the electrical properties have been reported. As proof of this concept, we show the possibility of combining PyPs and PyPs/ZnO-TPs with building materials to create smart materials capable of structural monitoring.
CI-1:IL19 Correlative and AI-Driven Multi-Modal Analytics as a Catalyst for Battery Innovation
S.H. CHRISTIANSEN¹˒²˒³, G. SARAU¹, A. BORCHERS¹, B. UZAKBAIULY¹, R.R. KOLAN¹, D. AUGSBURGER¹, T. HILDEBRAND⁴, P. SUTER⁴, ¹Fraunhofer Institute for Ceramic Technology and Systems – IKTS, Forchheim, Germany; ²Institute of Nanotechnology and Correlative Microscopy – INAM, Forchheim, Germany; ³Free University Berlin, Physics Department, Germany; ⁴Lucid Concepts GmbH, Zürich, Switzerland
Next-generation energy storage demands materials and architectures that balance energy density, lifetime, and sustainability. Achieving this requires more than incremental improvements in single characterization methods—it calls for an integrated, data-centric approach capable of linking structure, composition, and function across scales. We present a correlative and AI-driven analytical framework that unites multi-modal microscopy, spectroscopy, and operando testing with automated data fusion and machine-learning–based interpretation. Through spatial co-registration (nanoGPS) and digital workflows implemented via the Correlyze platform, we bridge datasets from electron, ion, optical, and x-ray modalities with chemical and electrochemical signatures. This enables quantitative, reproducible, and cross-scale insights into interfacial phenomena, transport kinetics, and degradation pathways in modern battery systems. By coupling deep-learning–based segmentation, feature extraction, and predictive modeling, the framework transforms heterogeneous experimental data into actionable knowledge—reducing the time from discovery to optimization. The same architecture supports both material-level studies (e.g., cathode and solid-electrolyte design) and device-level integration (e.g., printed or ceramic all-solid-state batteries), thereby unifying analytics and manufacturing feedback in a closed optimization loop. This approach defines a paradigm shift: from isolated material characterization toward AI-empowered, correlative analytics as a strategic enabler for high-performance and resource-efficient energy storage technologies. It provides the analytical backbone for predictive materials design, accelerated prototyping, and sustainable process control in the battery systems of the future.
Session CI-2 Recent developments in photoactive materials
CI-2:IL21 Extending the NIR Frontiers – Mapping Heat and Flow with Luminescent Lanthanide-doped Nanoparticles
E. HEMMER, University of Ottawa, Department of Chemistry and Biomolecular Sciences, Ottawa, ON, Canada
The remarkable optical properties of lanthanides (Ln) make Ln-based materials highly attractive for applications from biomedicine to optoelectronics and energy conversion. Their unique electronic structure enables upconversion and near-infrared (NIR) emission under NIR excitation. Particularly the latter is of interest for biomedical applications or in environments that are opaque to visible light. One the sought after applications is so-called nanothermometry, leveraging thermally-induced spectral changes into temperature sensors. NIR nanothermometers are promising for biomedical applications due to reduced optical scattering and absorption of NIR light that matches the biological transparency windows when compared to UV or visible light. Yet, the exploration of nanothermometers that operate in the NIR-IIc (1700–1880 nm) and NIR-III (2080–2340 nm) spectral regions remains scarce. This presentation will shine a light on recent advances in the design of nanoprobes based on Ln3+-doped sodium rare earth tetrafluorides that operate at such long wavelength, while also discussing remaining challenges. These include effects of stirring and flow on the photoluminescence: a limitation for reliable readout or a route to map velocity?
CI-2:IL22 Optimising the Structure of Mesoporous Semiconducting Oxides
A. SEVER ŠKAPIN1,2, M. KNAP1, E. ŠVARA FABJAN1, A. ŠULIGOJ3,4, U. LAVRENČIČ ŠTANGAR3, G. DRAŽIĆ4, N. NOVAK TUŠAR4,5, P. NADRAH1, 1Slovenian National Building and Civil Engineering Institute, Ljubljana, Slovenia; 2Faculty of Polymer Technology, Slovenj Gradec, Slovenia; 3University of Ljubljana, Faculty of Chemistry and Chemical Technology, Ljubljana, Slovenia; 4National Institute of Chemistry, Ljubljana, Slovenia; 5University of Nova Gorica, Nova Gorica, Slovenia
Mesoporous structures offer a large accessible surface area, which is crucial for enhancing the catalytic performance of semiconducting oxides. The evaporation-induced self-assembly (EISA) synthesis method is well suited for creating these mesoporous structures, but optimization of synthesis parameters for materials such as niobium(V) oxide has been limited. We demonstrate that key synthesis parameters: the duration of evaporation, relative humidity, and water content in the reaction mixture etc, significantly affect the specific surface area, mesoporous structure, and photocatalytic activity of the resulting oxide. Optimal conditions for the tested material yield the highest specific surface area. Furthermore, the ordered mesoporous structure plays an important role in improving photocatalytic performance. This research is necessary for determining the connection between synthesis parameters, the structure of photocatalysts, and photocatalytic efficiency. These materials are useful for the reduction of CO2 to energy-rich organic compounds and the production of H2 from water. These findings provide valuable insights for optimizing the synthesis of mesoporous semiconducting oxides to increase both specific surface area and photocatalytic activity.
Session CI-3 Green hydrogen production, storage and utilization
CI-3:IL24 Enhancement in Water Splitting based on robust Electroceramic Materials
D.HC CHUA, National University of Singapore, Department of Materials Sci & Engrg, Singapore
Today's electrocatalyst goes beyond traditional and expensive noble metals.For example, in water splitting for electrolyzers, a new generation of chalcogenides and phosphides have been shown to be highly effective and robust. In this report, we shall like to share our work where we explore, first, the base substrate and catalyst suport, before moving on to less well known and less common types of metal chalcogenides. It requires a good and rational design with a good control in the synthesis process to obtain materials with unique pre-determined structures and morphology. In this report, we will show that one can engineer various electroceramic materials with different dopants to form highly active metal dichalcogenide obtaining highly robust electrochemical catalyst. For example, one can engineer NiMoO4 electroceramics with NiS/NiP/MoS/MoP dopants which allow for very high current electrolyzer applications. We will also briefly introduce our work on MXene-based materials for water splitting.
CI-3:IL25 Study of Heterostructures based Interface Engineering for Solar driven CO2 Photoreduction to Fuel Production
C. SUNYONG LEE, H. CHARLES, P.J. CHENGULA, Department of Materials and Chemical Engineering, Hanyang University, Ansan, Republic of Korea
We report on the rational design and fabrication of interface-engineered heterostructures such as NiIn2S4/Sn-doped TiO2 nanofiber heterostructures and high-entropy oxide (HEO) of (CoCrFeNi)Ox/ NiTiO3 nanorods (NTO) heterostructure using various fabrication technologies. Sn-doping enhances the visible-light absorption and electron mobility of TiO2, while NiIn2S4, a narrow-bandgap sulfide, serves as a highly active photosensitizer. The intimate contact and favorable band alignment at the heterointerface facilitate efficient charge separation and directional electron transfer, forming a Z-scheme-like mechanism that preserves strong redox potential. The HEO/NTO heterostructure exhibited remarkable efficiency in photocatalytic CO2 reduction. Integrating HEO into NTO leads to the generation of intrinsic electric fields, which greatly improve charge transfer and decrease charge carrier recombination. The optimal HEO/NTO heterojunction displayed exceptional photocatalytic CO2 reduction activity, achieving a methanol production rate. The effective reduction of CO2 was primarily due to the effective transport of photo-excited electrons and holes facilitated by the HEO/NTO heterostructure. This study highlights the critical role of heterointerface engineering in designing next-generation photocatalysts and opens new avenues for solar-driven carbon-to-fuel conversion.
CI-3:L26 Optically Transparent WO3 Films with Organized Mesopores and Oriented Crystallinity as an Efficient and Robust Photoanode for Visible-Light-Driven Water Splitting
D. CHANDRA, Y. TSUBONOUCHI, Z.N. ZAHRAN, MASAYUKI YAGI, Department of Materials Science and Technology, Faculty of Engineering, Niigata University, Niigata, Japan
WO3 is a leading visible-light-driven photoanode for water splitting but characteristically suffers from instability and low Faradaic efficiency (FEO2, ~70%) for O2 evolution due to the surface photo-oxidation, competing with desired water oxidation. Herein we report an organized-mesoporous WO3 film with high optical transparency and oriented crystal panel growth, first demonstrating high efficiency and long-term stability for photoelectrochemical (PEC) water oxidation. The mesoporous WO3 film was directly fabricated on an FTO electrode via a surfactant-template strategy in combination with a unique in situ template-carbonization technique that preserves the crystalline mesoporous structure without collapse, exhibiting a high surface area (124 m2g-1), ultrathin pore walls (~10 nm) for shorter hole-migration lengths and preferential growth of the intrinsically active (002) monoclinic crystal-plane. The mesoporous WO3 electrode drastically enhanced the PEC performance, achieving incident photon-to-current conversion efficiencies (IPCE) of 49 and 41% at 420 nm and 1.23 V vs. RHE in acidic and neutral electrolyte, respectively, which is ~3-fold higher than the unspecified WO3. Mechanistic studies revealed a 3.6-fold increase in water oxidation rate constants (kO2 = 3.2 × 102 s-1) for mesoporous WO3 compared to untemplated WO3 (8.7 × 101 s-1). The mesoporous WO3 electrode facilitates deposition of finely dispersed CoOx co-catalyst within its mesoporous structure, exhibiting further acceleration (kO2 = 5.7 × 102 s-1) of surface water oxidation reaction and exceptional long-term stability during photoelectrolysis under neutral pH conditions, retaining 98% of its initial photocurrent (1.54 mA cm-2) after 30 h with FEO2 of 93%, which is rare achievement among hitherto-reported WO3 photoanodes.
CI-3:L28 Room and High Temperature Tensile Strength of Ultrathin 3% Yttria-stabilized Zirconia (3YSZ) Ceramic Tapes for Solid Oxide Fuel Cells (SOECs)
I. BOMBARDA, N. LANGHOF, S. SCHAFFÖNER, University of Bayreuth, Chair of Ceramic Materials Engineering (CME), Bayreuth, Germany
High temperature electrolysis (HTEL) has several advantages compared to other types of solid oxide cell (SOC) technologies, including a high efficiency at T = 850 °C when combined with an exothermic process. To reduce costs, increase lifetime and improve scale up production of electrolyte supported SOCs, a key property is the cell mechanical stability, which for electrolyte supported cells is mainly provided by the ceramic electrolyte. In this study, the authors investigated the tensile and ring-on-ring properties of ultrathin (t = 90 µm) 3YSZ tapes at room and high temperature (T = 850 °C). A test setup and sample preparation procedure were developed for the tensile test. The tensile test concept was then adapted to a high temperature setup, allowing the tensile test at operating temperature with 90% valid samples. A 50 % strength drop was observed in tensile and ring-on-ring compared to room temperature. The high temperature tensile testing allowed the evaluation of an effective volume of Veff = 4.1 mm3 and the individuation of bulk defects, in opposition with the ring-on-ring test where only the surface defects could be assessed. The defects after the tensile test were measured and classified as under-critical, testifying the presence of under-critical crack growth.
CI-3:IL32 Fabrication of Ba1-xSrxTiO3 Tetragonal Photocatalyst for Water Splitting
MIKI INADA1,2, JUN TAE SONG1,2, MOTONORI WATANABE2, TATSUMI ISHIHARA1,2, 1Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Fukuoka, Japan; 2International Institute for Carbon-Neutral Energy Research, Kyushu University, Fukuoka, Japan
Usually, BaTiO3 particles via hydrothermal synthesis were cuboidal shape with cubic crystalline structure. In our previous study, rod-like particles with tetragonal structure can be obtained by ethylene glycol addition to reacting solvent during hydrothermal synthesis. We experimentally and computationally found that excess OH with substitution of oxygen sites stabilizes the tetragonal crystal (Ceram. Int., 41 (2015) 5581, Inorg. Chem., 57 (2018) 5413). The OH, usually as an undesirable group in crystals, acts as an important role for formation and stabilization of metastable crystal, and that highly crystalline particles can be obtained by using oxyhydroxides as a precursor. In this presentation, the synthesis of highly crystalline Ba1-xSrxTiO3 tetragonal solid solution particles using the tetragonal Ba1-(1/2)yTiO3-y(OH)y metastable crystals as a precursor, and the applications to water-splitting photocatalyst will be explained.