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molecular precursors, bottom-up approach, sol-gel process, upconversion, nanostructured metal oxides, metal fluoride, metal chalcogenide, nanoparticles, thin films, 2D materials, heterogeneous catalysis, inorganic-organic hybrid materials
EDUCATION AND PROFESSIONAL EXPERIENCE
2021: Promoted to outstanding class of Associate Professor (MdC hors classe) by National Council of Universities (CNU)
2016: Habilitation à diriger des recherches HDR (French degree to conduct independent research), ‘Molecular precursor engineering for the development of oxide, non-oxide and hybrid inorganic-organic nanomaterials’, University of Claude Bernard Lyon 1 (UCBL), France
2011: Maître de Conférences (Assistant Professor), UCBL, France
2010-2011: Post-doctoral associate, Laboratoire de Physico-Chimie des Matériaux Luminescents, LPCML (now ILM), UCBL, France (supervisor: Prof. C. Dujardin)
2004-2010: Post-doctoral associate, Institut de Recherches sur la Catalyse et l’Environment du Lyon, IRCELYON (formerly IRC), UCBL, France (supervisor: Prof. L. G. Hubert-Pfalzgraf 2004-2006, and Prof. S. Daniele 2007-2010)
2002-2004: Lecturer, Chemistry Department, Bundelkhand University, Jhansi, India
1996-2002: PhD in Chemistry, ‘Synthesis of novel metal alkoxide derivatives’, Department of Chemistry, University of Rajasthan, Jaipur, India (supervisor: Prof. A. Singh)
1993-1995: Master’s in Chemistry, Department of Chemistry, University of Rajasthan, Jaipur, India
ACADEMIC AWARDS, FELLOWSHIPS AND DISTINCTIONS
2022: Emerging Investigator of Crystal Growth & Design (an ACS journal)
2019: University Scientific Excellence Award (PEDR) by CNU32
2015: University Scientific Excellence Award (PEDR) by CNU32
2004: CNRS Post-Doctoral Fellowship at IRC, Lyon, France
2003: Prof. A. K. Dey Young Scientist Award of Indian Chemical Society
2002: ISCA Best Paper Award of Indian Science Congress Association
2002: Senior Research Fellowship of Council of Scientific and Industrial Research (CSIR), India
2000: Joint CSIR-UGC National Eligibility Test (NET) for Lectureship
~90 articles published in peer reviewed journals (h-index = 24 (Scopus, Web of Science)
- ~50 articles as an independent researcher and corresponding author including 6 reviews in Chem. Rev., Chem. Soc. Rev., Chem. Eur. J., Chem. Commun., Coord. Chem. Rev & Dalton Trans.
- Invited articles (>15) in Chem. Commun., Chem.-Eur. J., Mater. Today Chem., Dalton Trans., Cryst. Growth Des., ChemCatChem, ACS Omega, CrystEngComm, Eur. J. Inorg. Chem., Polyhedron) and book chapters (2)
- Articles chosen for cover art (ChemCatChem 2023, Chem.- Eur. J. 2021, Dalton Trans. 2018, Chem. Soc. Rev. 2007), Frontispiece (Chem.- Eur. J. 2020), as HOT article (ChemCatChem 2023, Dalton Trans. 2021) or featured among TOP 25 articles (Coord. Chem. Rev. 2008, Polyhedron 2010…)
- Keynote or invited talks and oral presentations in international conferences & world-wide institutions (~35)
- Carnot MICA (2023) ‘Mesostructurated oxo(hydroxo)fluoride acid catalysts (FluoCat)’, Coordinator
- ANR (2023-2027) ‘Rare Earth-Doped Metasurfaces for Upconversion and Photon Avalanching (README)’, Scientific leader
- ANR (2017-2020), Upconverting photon harvester for photocatalysis (UPHocat), Scientific leader
I am/was also involved in several other collaborative research projects which include
- LABEX iMUST (2022-2024), 2D heterostructures exploration and tuning for photocatalytic water splitting, from type-II to Z-Schemes (Z-project).
- PEPR SPLEEN (2023-2027), ‘Photo-conversion of CO2 with solar energy by associating up-conversion materials with photocatalyst heterojunctions mimicking the Z-scheme and micro-nanopatterned to confine light by photonic crystals (HOCUSPOCUS)’
- LABEX iMUST (2016-2019), Oxide thermoelectrics nanostructured by spinodal decomposition (OTHELLO)
- LABEX iMUST contract to support the PhD of Khaled SOUSSI (2014-2016), ‘Vapor-phase elaboration of supported intermetallic nanocatalysts containing non-precious metals for the selective hydrogenation of acetylene’
- Exploratory project of the INSIS Energy Unit (2013-2014), ‘Génération d’architectures nanometriques intra- et inter-granulaire dans des oxydes pour de hauts rendements de conversion thermoélectrique de l’énergie (GREAT)’
Ph. D. THESIS SUPERVISION / CO-SUPERVISION
Khaled SOUSSI (2013-2017), Wenzhang FANG (2014-2017, co-supervision with East China University of Science & Technology, Shanghai, China), Alexandre VERCHÈRE (2016-2019), Santiago DE BRITO (2018-2019, co-supervision with Federal University of Ceará, Brazil), Sweta GAHLOT (2017-2020), Bhagyesh PUROHIT (2017-2021), Roua Ben SALEM (2019-223).
MASTER (M2) THESIS SUPERVISION / CO-SUPERVISION (6-month internship)
Ying CHEN (2013), Hana AYADI (2014), Dan DU (2015), Suneel LANKA (2016), Sweta GAHLOT (2017), Sameh GALAL (2019), Nidal RAYDAN (2020), Christopher HABU (2021), Yahminiy GANESHAN (2022), Fouad ELGAYAR (2023), Souha DENGUEZLI (2023)
REVIEWING AND EVALUATION ACTIVITIES
- Reviewer of scientific papers: ~300 articles for the international journals of RSC, ACS, Wiley-VCH, Elsevier, Springer, Taylor & Francis…):
- Evaluator of scientific projects of national and international agencies [National Research Agency (ANR), German Research Foundation (DFG), National Science Center, Poland (NCN), University Grants Commission (UGC, India)…]
- Reviewer of PhD theses from national and international universities [East China Uni. Sci. & Tech., Shanghai (China), Tezpur University (India), Vellore Inst. Technology (India), Uppsala University (Sweden), University of Bologna (Italy), University of Messina (Italy), University of Catania (Italy) …]
CO-ORGANISER OF SYMPOSIA IN INTERNATIONAL CONFERENCES:
- E-MRS Spring Meeting 2022, Symposium D1 ‘Materials for nanoelectronics and nanophotonics’, May 30-June 3, 2022, Strasbourg, France.
- American Ceramic Society’s International Conference and Exposition on Advanced Ceramics (ICACC), member of organizing committee of Symposium S7 ‘Molecular-level processing of functional materials’, every year in January/February, Daytona Beach, USA (involved since 2019).
PROFESSIONAL AFFILIATIONS AND INSTITUTIONAL RESPONSIBILITIES
- Program Coordinator, International Master’s M2 Synthesis, Catalysis, and Sustainable Chemistry (M2 SCSC) at UCBL
- In-charge, Indo-French international relations, Chemistry Doctoral School of University of Lyon
- Member, Council of Institute, IRCELYON
- Member, Institutional Security Team, IRCELYON
- Member, GDR ‘Réseau des Acteurs Français de l’ALD (RAFALD)’
- Member, American Chemical Society, American Ceramic Society and Indian Chemical Society
- Member, advisory boards/organizing committees of several national/international conferences
- Member, Advisory Board on the composition of selection Committees (section 32), UCBL (2013-2016)
- Member, delegation for the PhD Tour in India, organized by Campus France (24 Feb-4 March, 2017)
- Member, GDR 'Oxydes fonctionnels : du matériau au dispositif (OXYFUN)' (2014-2017)
- President, jury of Baccalauréat Général, 0094 Series S, (July 4-9, 2013)
Dr. Shashank Mishra received his M. Sc. and Ph. D. degrees in Chemistry from the University of Rajasthan (UoR, India) and, subsequently, served as a lecturer for two years at Bundelkhand University (India) before moving to France for his post-doctoral studies. His two post-doctoral stints at the institutes IRCELYON and LPCML of the University of Claude Bernard Lyon 1 (UCBL) involved studies on molecular precursor chemistry and luminescent/scintillating materials, respectively. In 2011, he was appointed as a faculty at UCBL, where he successfully completed his habilitation in 2016. Currently, he is an Associate Professor and the Coordinator of a second-year international master's program in Synthesis, Catalysis, and Sustainable Chemistry (M2 SCSC) at UCBL. His research interests are concerned with different facets of inorganic and metal-organic chemistry with special focus on molecular precursor engineering and understanding their transformations via solutions or vapor phase routes to oxide and non-oxide nanomaterials for different applications (optics, energy, catalysis, ...). He also focuses on halometallate-based perovskite-inspired materials for diversified applications. He has authored / co-authored about 100 original research publications, reviews and book chapters.
Our research mainly focuses on developing new and easy-to-scale up routes to rationally designed (hetero)metallic molecular precursors, identifying solutions or vapor phase strategies of their atom-economic conversion to inorganic nanomaterials and understanding structure/property relationships during this transformation. Using this ‘bottom-up’ approach, we have made significant contributions to the understanding of chemical processing of functional nanomaterials as well as in demonstrating their potential for applications in the field of catalysis, energy and optics. Some of the axes being pursued currently are given below:
1. Starting point: Molecular precursors
In the bottom-up approach of the synthesis of nanomaterials, the molecular precursors are used as building-block units with precisely controlled and tunable chemical composition to create nanomaterials with the desired properties. These molecules are transformed into inorganic nanostructures and films by soft-chemical methods in either solution phase (sol-gel process or metal-organic decomposition, MOD) or gas phase (metal-organic chemical vapor deposition, MOCVD). Thus, these well-defined precursors control the evolution of materials from single or poly-atomic units to extended solid-state structures, allowing for facile control over uniform particle size distribution and stoichiometry and leading to desired physical and chemical properties. The main advantages of this approach are: i) low processing temperatures (due to the pre-existing chemical bonds among constituent atoms), ii) low organic contamination (due to clean ligand elimination mechanisms) and, iii) higher quality of the materials (due to homogeneity at molecular level). As an authority on molecular precursors engineering, I’ve written several review articles and book chapters (mostly invited) dealing with main principles, state of the art and perspectives of this approach of the synthesis of nanomaterials (Figure 1).
2. Functional nanoparticles
Nanoparticles (NPs) have several special characteristics such as size-dependent light absorption, large surface area and a very high percentage of atoms at surface, which make them excellent materials for several applications. In our group, we strive to make functional NPs of high quality (controlled size, shape and distribution, designed surface functionality, good dispersibility, etc.) by hydrolyzing or thermally decomposing single source precursors in solution-phase for catalytic, light-harvesting and energy applications. Some of the aspects being explored are given below:
2.1. Isolation of reactive molecular intermediates during the course of formation of nanoparticles
In the bottom-up approach of materials synthesis, identification of intermediate species operating at the intersection of molecular and nanometric levels is a key aspect in understanding the mechanism of molecule-to-nanoparticle formation and, therefore, achieving fine control over the synthetic conditions to prepare NPs with controlled composition and properties. However, it is challenging to isolate and characterize these intermediates unambiguously because they are usually highly reactive in nature. We have used carefully chosen ligands with suitable reactivity to isolate and characterize reactive molecular intermediates during the course of formation of binary and ternary coinage metal selenide NPs (Figure 2). Isolation of these intermediates helps in studying the fundamentals of nucleation and growth and establishing a precursor-mediated pathway for the formation of NPs with complex composition.
2.2. Molecular precursors with low thermal decomposition temperature
Low-temperature synthesis of functional NPs is a key-step to their incorporation in technologies that are sensitive to harsh conditions. Unlike metal oxides, the precursor’s chemistry for the low-temperature solution-phase synthesis of functional metal chalcogenide nanomaterials is yet to realize its potential, and an important area in this direction is the exploration and identification of the reagents that are reactive at low temperature. We have exploited the facile decomposition mechanism of certain chalcogenoethers as a strategy to obtain molecular precursors, which decompose at low- or even room temperature to afford phase-pure and highly crystalline binary or ternary metal chalcogenide NPs (Figure 3). This strategy is being further explored to obtain metastable or compositionally complex nanomaterials with greater control.
Key articles: Chem. Commun. 2022, 58, 10136-10153; Chem. Eur. J. 2021, 27, 10826–10832; Inorg. Chem. 2020, 59, 7727-7738; Dalton Trans. 2020, 49, 3580–3591; Dalton Trans. 2018, 47, 8897–8905; Chem. Asian J. 2016, 11, 1658-1663.
Nanomaterials via Single-Source Precursors: Synthesis, Processing and Applications, Eds. A. W. Apblett, A. R. Barron & A. F. Hepp, Chapter 6, p. 201-218, Elsevier, 2022 (book chapter)
2.3. Employing anhydrous molecular precursors as a strategy to enhance up-conversion efficiency in Ln3+-doped metal fluorides nanoparticles
Upconversion (UC) phenomenon is characterized by the successive absorption of two or more pump photons via intermediate long-lived energy states, followed by the emission of the output radiation at a shorter wavelength than the pump wavelength. Although the UC Phenomenon is known since mid-1960s and have been used for long in the bulk materials, the nanometric synthesis of UC materials started only in mid-2000s. A major challenge in the field of UC nanomaterials is to enhance upconversion luminescence. In comparison to conventional luminophores, quantum yields of lanthanide-doped UC nanoparticles are extremely low (typically less than 1%) and, in general, about an order of magnitude lower than those of corresponding UC bulk materials. It is well-known that –OH defects in the nanocrystals are the primary cause of upconversion quenching. We have employed designed anhydrous molecular precursors as a synthetic strategy to enhance upconversion efficiency in Yb3+ and Tm3+-co-doped MM'F4 (M = Li, Na; M' = Y, Gd), GdF3 or BaYF5 nanoparticles (Figure 4). The bottom-up synthesis not only facilitates a better control over the composition, structure and morphology of the nanomaterials, but anhydrous conditions also minimize –OH functionality on the surface of the upconverting NPs. A detailed up-conversion studies done in collaboration with Dr. G. Ledoux at ILM reveal that the uniform nanoparticles obtained from these anhydrous single source precursors had i) superior up-conversion intensity than the UC materials produced from the hydrated inorganic salts, and ii) a comparable efficiency with bulk materials of the same composition.
Key articles: ACS Appl. Nano Mater. 2023, 6, 2310–2326; Mater. Today. Chem. 2020, 17, 100326; ACS Photonics 2019, 6, 3126-3131; J. Phys. Chem. C. 2018, 122, 888-893; RSC Adv. 2015, 5, 100535-100545; Chem. Asian J. 2014, 9, 2415‒2421; Dalton Trans. 2012, 41, 1490‒1502; Chem. Commun. 2010, 46, 3756‒3758.
3. Thin films and 2D materials
The controlled synthesis of thin-film and 2D materials in terms of thickness/number of layers, morphology, and structure is a key step in many different applications. Using novel functional metal alkoxide precursors, we have elaborated several metal oxide films, particularly those which find application as transparent conductive oxide (TCO) coatings, such as group 13 metal oxides M2O3 (M = Ga, In), F-doped SnO2 or Ti-doped SnO2, either by spin-coating or MOCVD (Figure 5). The main focus in this field has been on the development of modified metal alkoxides as improved sol-gel precursors to afford stable sol with appropriate rheology and spin-coating characteristics (e.g., RSC Adv. 2016, 6, 1738 or Dalton Trans., 2009, 2569), or functionalized homo and heterometal alkoxides containing fluorine and/or asymmetric substitution as MOCVD precursors with improved volatility and solubility (e.g., Cryst. Growth Des., 2022, 22, 54 or Inorg. Chem. 2020, 59, 7167). For the two-dimensional (2D) materials, which have strong layer-depending properties, the work has mainly focused on mild synthesis of inorganic metal mono- or dichalcogenides (e.g. SnE or SnE2, MoE2, WE2, etc. where E = S or Se) with tuned layer-depending properties using single source precursors containing chalcogenoethers or chalcogenourea ligands (e.g., Dalton Trans. 2021, 50, 12365 or Dalton Trans. 2021, 50, 17346) or a single-step method to prepare organic g-C3N4 with high surface area (J. Environ. Chem. Eng. 2021, 9, 105587).
4. Designed metal alkoxide precursors for sol-gel derived metal oxide nanomaterials
The versatility of metal alkoxides as convenient precursors to advanced materials via sol-gel process is widely acclaimed. However, the use of classical metal alkoxides in the sol-gel process is of limited applications because of their extremely high susceptibility towards hydrolysis and poor stability of the resulting colloidal solutions. Out work on metal alkoxides has focused on two aspects: i) modification of metal alkoxides using Functional alcohols, which not only alter physical and chemical properties of the precursors but also, due to their action as surfactants, stabilize the colloidal solutions obtained during the hydrolysis, and ii) development of well-characterized heterometallic alkoxides, which as ‘single-source’ precursors provide greater homogeneity at molecular level for mixed-metal oxide (Figure 6).
4.1. Mesoporous metal oxides with high surface area for catalytic applications:
To modify the classical metal alkoxides and to make them more attractive sol-gel precursors, we have mainly used aminoalcohols of varying substituents. The metal complexes derived from these functional alkoxides show a great structural variety and improved sol-gel characteristics to obtain various forms of the nanomaterials (transparent metallogels, monolithic xerogels, thin films, nanopowder with high surface area, etc). For instance, the binary and ternary group 13 metal oxides not only have high surface area but also stabilize smaller gold nanoparticles (sub-5 nm) to afford active supported gold catalysts Au/M2O3 (M = Ga, In) and Au/Al4Ga2O9 for the aerobic trans-stilbene epoxidation reactions (Figure 7). Under standard conditions developed by Dr. Valerie Caps, these supported catalysts showed the conversion rate and the selectivity better than the reference Au/TiO2 catalyst from the World Gold Council. These modified alkoxides were also used for obtaining atomically dispersed Nb and Pb within TiO2 having high surface areas and tunable acidic properties. The catalytic activity of these catalysts for dihydroxyacetone (DHA) transformation were studied in collaboration with Dr. Nadine Essayem, which showed a significantly increased conversion of DHA for these catalysts as compared to undoped TiO2. Upon increasing the doping%, the base-catalyzed pathway became the prevailing mechanism at the expense of the usual acid-catalyzed pathway leading to formation of Pyruvaldehyde.
Key articles: App. Catal. A: General 2023, 658, 119165; Dalton Trans. 2021, 50, 1604; ACS Omega, 2019, 4, 5852; Eur. J. Inorg. Chem. 2013, 500; Dalton Trans. 2010, 39, 7440.
4.2. Dense nanostructured metal oxide ceramics for thermoelectricity: Thermoelectric materials, which convert thermal energy into electric energy, have attracted a renewed interest over the past decade, thanks to the discovery of some new thermoelectric materials with high values of the thermoelectric figure-of-merit (zT). The TiO2-SnO2 system is very attractive as a possible candidate for oxide thermoelectric materials because not only a variety of stable nanostructures with low thermal conductivity can be reproduced in this system but it is also free from toxic or precious elements. We synthesised new complexes of the formula [MSnCl4(OR)x(ROH)y] (M = Ti, Nb, Ta; x = 4, 5; y = 0-2; R = Et, Pri) as single-source precursors to obtain Nb5+ /Ta5+-doped TiO2-SnO2 nanoparticles. In collaborative work with INSA and ILM (Prof. G. Fantozzi, Dr. S. Le Floch, Dr. S. Paihes and Dr. D. Machon), we have shown that spinodal decomposition of the SnO2-TiO2 system is possible using the SPS technique at a temperature of 1100°C, starting from nanoparticles based on a Sn/Ti = 50:50 solid solution. The materials are highly densified (>90%) while retaining nanometric grain sizes (<100 nm) (Figure 8). In order to increase the electrical conductivity of the oxide materials and in particular of the TiO2-based matrix in the TiO2-SnO2 system, we also synthesised Nb5+-doped TiO2 nanoparticles. Densification by SPS was accompanied by the anatase-rutile transformation and the appearance of a new TiNb2O7 phase.
Key articles: J. Eur. Cer. Soc. 2023, 43, 2783; Nanoscale 2022, 14, 14286; Phys. Chem. Chem. Phys. 2020, 22, 13008; Dalton Trans., 2015, 44, 6848; Inorg. Chem. 2010, 49, 11184.
5. Titania-combined heterostructures for photocatalysis
Titania (TiO2) is one of the most promising photocatalysts. However, a band gap of ~3.2 eV for the most active anatase phase limits its application in the UV region (<398 nm) only, leaving almost 95% solar energy being unused. We are interested in developping titania-combined heterostructures which can make use of above unutilized solar energy.
5.1. Near-infrared driven photocatalysis of the nanocomposites UCNPs@TiO2:
To extend the absorption range of TiO2 into the IR region of sunlight, which accounts for almost half of the energy of the sunlight radiation (as against only about 5% of the UV radiation), we have combined it with upconverting NPs. Two strategies have been used to get IR-active photocatalysts (Figure 9): i) construction of core-shell TiO2@NaGdF4:Yb3+,Tm3+ photocatalyst where the core NaGdF4:Yb3+,Tm3+ acts as a medium to convert NIR to UV-visible light via multiphoton upconversion processes, and ii) embedding LiYF4:Yb3+,Tm3+ UCNPs in transparent TiO2-based metallogels which on subsequent drying provided highly homogeneous UCNPs-TiO2 composites of variable composition (1−10% NPs) and very high specific surface areas (435-580 m2/g). These IR-active photocatalysts showed good degradation of the methylene blue (MB) dye, both with laser and solar irradiation, thus validating the concept of transferring the NIR into visible light to activate the anatase TiO2 for photocatalysis.
5.2. Enhanced photocatalytic activity of metal chalcogenide-TiO2 nanocomposites:
Our success in ultra-mild synthesis of binary and ternary coinage metal chalcogenide nanoparticles (MCNPs), achieved without using any reducing reagents or surfactants and within a short reaction time at room temperature, offered an easy preparation of MCNPs–TiO2 nanocomposites for photocatalytic applications without compromising the structural and morphological characteristics of TiO2 and without having any organic ligands around the NPs, which would otherwise diminish the photocatalysis. As compared to the well-known benchmark for photocatalysis, TiO2 (P25), these MCNPs–TiO2 nanocomposites show clear improvement in their photocatalytic activity for the photodegradation of formic acid (studied in collaboration with Dr. C. Guillard and F. Dappozze). DFT calculations, performed at Uppsala University by the group of Prof. R. Ahuja, established semi-metallic behavior of CuAgSe NPs and formation of a semimetallic-semiconductor CuAgSe–TiO2 heterojunction which allowed a better charge separation to enhance its photocatalytic activity (Figure 10).
6. Perovskite-inspired halometallate hybrid materials:
We are also interested in perovskite-inspired hybrid materials in order to harness their semiconducting and luminescent properties for photovoltaics, LED and other applications. These hybrid materials based on solvated lanthanide/barium cations and halometallate anions demonstrate a wide variety of structural architectures, with several of these complexes undergoing transformations in the solid state or liquid phase by systematic substitution of the metal cation coordination ligands and/or by condensation of halometallate anions (Figure 11). We have shown that these hybrid halometallates can serve as a template, and have structure-directing effect, for constructing unique hybrids containing three different metals.
Key articles: Inorg. Chem. 2014, 53, 11721; Eur. J. Inorg. Chem. 2012, 2749; Dalton Trans. 2009, 4954; Inorg. Chem. 2008, 47, 9333; CrystEngComm 2008, 10, 814; Dalton Trans. 2008, 6296; CrystEngComm 2012, 14, 3894; Dalton Trans. 2008, 620; Dalton Trans. 2007, 410.
We collaborate both within academia as well as with some industrial partners (some of the collaborators involved in current projects are given below). If you are interested in collaborating with us, please contact me directly on my e-mail.
Within UCBL: Dr. E. Jeanneau (Centre de diffraction), Dr. N. Essayem, Dr. A. Mesbah, Dr. C. Guillard, Dr. F. Dappozze, Dr. E. Puzenat, Dr. M. S. Prévot, Dr. A. Quadrelli, Dr. F. Morfin and Dr. J.-L. Rousset (IRCELYON), Prof. S. Daniele (CP2M), Dr. G. Ledoux, Prof. C. Dujardin, Dr. S. Le Floch and Dr. S. Pailhès (ILM).
Outside UCBL: Dr. C. Seassal (INL, Ecole Centrale de Lyon), Prof. S. Mathur (Cologne, Germany), Prof. R. Ahuja (Uppsala University, Sweden), Prof. J. Zhang (East China University of Science & Technology, Shanghai), Dr. B. Lebeau (IS2M, Mulhouse), Prof. J.-L. Blin (Université de Lorraine), Dr. H. Guillon (KEMSTREAM, Montpellier), Dr. N. Gogoi (Tezpur University, India).
Ours is a synthetic inorganic and metal-organic chemistry group, with a prime focus on the design, synthesis and understanding of the new molecular precursors and harnessing their properties and reactivities to obtain inorganic nanostructures and films through ‘soft-chemical’ processes. Molecular precursor engineering is a significantly challenging process that often starts with designing/choosing an appropriate organic ligand capable of bringing about suitable properties in the metal-organic precursors. Over the years, we have designed and employed several classes of ligands containing all-oxygen (e.g., functional alcohols), mixed oxygen and nitrogen (e.g., amino alcohols), all-nitrogen (e.g., triazenes) or chalcogen (e.g., chalcogenoethers) atoms as binding sites. Judicious choice of denticity, asymmetry and substituting groups of these ligands determines the properties of the metallic precursors and their suitability for solution- or vapor-phase chemical processes. The synthesis of these precursors requires demanding skills as it often involves handling of highly air- and moisture-sensitive reagents. In our group, we have developed hundreds of original metal-organic precursors with significantly improved physical properties as well as sol-gel and decomposition characteristics, particularly for oxides, fluorides and chalcogenides nanomaterials. The sol-gel use of these precursors requires studies on their hydrolysis and condensation characteristics, stability of the colloidal dispersion obtained after the hydrolysis or gelation optimization to obtain hetero-component metallogels, monolithic xerogels, spin-coated thin films or atomically dispersed NPs with high surface area (Figure 12). The metal-organic decomposition (MOD) method in solution phase warrants exploration and identification of the reagents that are reactive at low temperature and knowledge of possible decomposition mechanism of the precursors to have better control on the properties of the synthesized nanoparticles (NPs) as well as surface functionality of NPs to impart desirable properties in them. On the other hand, an emphasis is placed on the volatility and mass transportation studies for the MOCVD precursors as the gas-phase chemical process necessitates an appropriate partial pressure of the molecular precursors.
In our group, students receive vigorous training on
i) synthetic inorganic and metal-organic chemistry, with extensive use of inert atmosphere glove box or Schlenk tube & vacuum line techniques,
ii) employing chemical routes such as sol-gel process, metal organic decomposition (MOD) or chemical vapor deposition (CVD) methods to convert molecular precursors into the nanomaterials (bottom-up approach).
iii) measurements and/or interpretation of several physico-chemical characterization techniques at molecular and nanometric scales (FT-IR, solid- and solution phase NMR, UV-visible, DTA-TGA, single crystal X-ray diffraction, powder XRD, TG-DTA, SEM, TEM, BET surface area, AFM, XPS, etc.), and
iv) measurements and interpretation of optical, luminescent and upconversion properties and their catalytic activities, often in collaboration with our project partners and utilizing excellent facilities available at the host institute IRCELYON.
I teach a range of different courses at post- and under graduate levels at UCBL. As a course instructor, I have designed and developed new teaching modules for the two international master’s courses:
"Inorganic nanomaterials" (full unit) for "M2R Synthesis, Catalysis, and Sustainable Chemistry (CHM2187M)" at UCBL, and
"Micro- and nanofabrication" (half unit) for "M1 Nanoscale Engineering (CHM1148M)", which is a joint master’s program by three Lyon-based institutions: UCBL, ECL and INSA. These courses serve to acquaint students, who have extremely diverse academic background, with the ‘bottom-up’ approach of the synthesis of nanomaterials.
My other courses and tutorial classes courses at master’s and under graduate levels are concerned with general inorganic, coordination and organometallic chemistry. My laboratory courses mostly deal with the synthesis of transition metal complexes, their reactivities and characterization techniques but also involve new practical exercises based on my research themes, i.e., sol-gel process and colloidal synthesis of nanoparticles and thin films for photocatalysis and photovoltaic applications. Besides imparting training in chemical synthesis and characterizations, these practical sessions also aim to teach the students basic safety regulations in the laboratory, literature survey using computers and writing a scientific report correctly.
I also have an active research group where I provide supervision to postdoctoral researchers, PhD and masters students. Over 20 students have graduated so far from the group, mostly completing on time.
APPLIED CATALYSIS A-GENERAL, 2023, 658, p.
CHEMCATCHEM, 2023, p.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, 2023, 43(7), pp. 2783-2793
ACS APPLIED NANO MATERIALS, 2023, p.
JOURNAL OF THE INDIAN CHEMICAL SOCIETY, 2022, 99(2), p. 100322
NANOSCALE, 2022, 14(38), pp. 14286-14296
CHEMICAL COMMUNICATIONS, 2022, p.
JOURNAL OF MOLECULAR STRUCTURE, 2022, 1260, p.
INORGANICA CHIMICA ACTA, 2022, 531, p.
DALTON TRANSACTIONS, 2021, 50(36), pp. 12365-12385
DALTON TRANSACTIONS, 2021, p.
MOLECULES, 2021, 26(17), p.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING, 2021, 9(4), p.
CHEMISTRY-A EUROPEAN JOURNAL, 2021, 27(42), pp. 10826-10832
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, 2021, 2021(20), pp. 1976-1983
DALTON TRANSACTIONS, 2021, 50(5), pp. 1604-1609
Ceramics, 2020, 3(4), pp. 507-520
Materials today chemistry, 2020, 17, p. 100326
Chemistry-a european journal, 2020, 42 , pp. 9292-9303
Physical chemistry chemical physics, 2020, 22, pp. 13008-13016
Inorganic chemistry, 2020, 59, pp. 7727-7738
Inorganic chemistry, 2020, 59, pp. 7167-7180
Dalton transactions, 2020, 49, pp. 3580-3591
Acs photonics, 2019, 6, pp. 3126-3131
Applied organometallic chemistry, 2019, 33, p.
Acs omega, 2019, 4, pp. 5852-5861
Dalton transactions, 2018, 47, pp. 8897-8905
Polyhedron, 2018, 152, pp. 84-89
European journal of inorganic chemistry, 2018, pp. 751-758
Journal of physical chemistry c, 2018, p.
Physica status solidi a-applications and materials science, 2018, 215, p.
Journal of physical chemistry c, 2017, 121, pp. 17068-17076
DALTON TRANSACTIONS, 2017, 46(38), pp. 13055-13064
Dalton Transactions, 2017, 46, pp. 8664-8672
Physical Chemistry Chemical Physics, 2017, 21, pp. 13875-13881
Chemistry : an Asian Journal, 2016, 11, pp. 1658-63
Journal of Coordination Chemistry, 2016, 69, pp. 135-148
RSC Advances, 2016, 6, pp. 1738-1743
Chemical reviews, 2015, 115, pp. 8379-448
RSC Advances, 2015, 5, pp. 100535-100545
Dalton Transactions, 2015, 44, pp. 6848-6862
Inorganic Chemistry, 2014, 53, pp. 11721-11731
Chemistry - An Asian Journal, 2014, 9, pp. 2415-2421
Nano Letters, 2014, 14, pp. 269-276
Dalton Transactions, 2013, 42, pp. 12633-12643
European Journal of Inorganic Chemistry, 2013, pp. 500-510
European Journal of Inorganic Chemistry, 2012, xx, pp. 2749-2758
CrystEngComm, 2012, 14, pp. 3894-3901
Dalton Transactions, 2012, 41, pp. 1490-1502
Inorganic Chemistry, 2010, 49, pp. 11184-11189
Dalton Transactions, 2010, 39, pp. 7440-7443
Chemical Communications, 2010, 46, pp. 3756-3758
Polyhedron, 2010, 29, pp. 500-506
Dalton Transactions, 2009, pp. 2569-2577
Lanthanide complexes in hybrid halometallate materials: interconversion between a novel 2D microporous framework and a 1D zigzag chain structure of iodoargentates templated by octakis-solvated terbium(III) cation
Dalton Transactions, 2009, pp. 4954-4961
Thermal dehydration of Y(TFA)(3)(H2O)(3): Synthesis and molecular structures of Y(mu, eta(1):eta(1)-TFA)(3)(THF)(H2O) (1 infinity) center dot THF and Y-4(mu(3)-OH)(4)(mu, eta(1):eta(1)-TFA)(6)(eta(1)-TFA) (eta(2)-TFA)(THF)(3)(DMSO)(H2O) center dot 6THF (TFA = trifluoroacetate)
Inorganic Chemistry Communications, 2009, 12, pp. 97-100
Coordination Chemistry Reviews, 2008, 252, pp. 1996-2025
Crystal-to-crystal transformations in heterometallic yttrium(III)-copper(I) iodide derivatives in a confined solvent-free environment: Influence of solvated yttrium cations on the nuclearity and dimensionality of iodocuprate clusters
Dalton Transactions, 2008, pp. 620-630
CrystEngComm, 2008, 10, pp. 814-816
Reactions of metal iodides as a simple route to heterometallics: synthesis, structural transformations, thermal and luminescent properties of novel hybrid iodoargentate derivatives templated by YL8 (3+) or YL7 (3+) cations (L = DMF or DMSO)
Dalton Transactions, 2008, pp. 6296-6304
Inorganic Chemistry, 2008, 47, pp. 9333-9343
European Journal of Inorganic Chemistry, 2007, pp. 602-608
From discrete [Y(DMF)8][Cu4(µ3-I)2(µ-I)3I2] ion pairs to extended [Y(DMF)6(H2O)2][Cu7(µ4-I)3(µ3-I)2(µ-I)4(I)]1∞ and [Y(DMF)6(H2O)3][CuI7CuII2(µ3-I)8(µ-I)6]2∞ arrays by H-bond templating in a confined solvent-free environment
Dalton Transactions, 2007, pp. 410-413
Inorganic Chemistry Communications, 2007, 10(1), pp. 15-19
Polyhedron, 2007, 26, p. 66
Chemical Society Reviews, 2007, 36, pp. 1770-1787
Hydrolysis of a (2-Propanol)yttrium Triiodide Complex in the Presence of Glymes: Synthesis and X-ray Structures of Hydroxo-Bridged Dinuclear Yttrium Complexes and Their Applications in Materials Science
European Journal of Inorganic Chemistry, 2007, 15, pp. 2208-2215