Le développement d'un nouveau système photo-initiateur 1 photoinitiateur capable d'absorber fortement la lumière dans la région de la lumière visible et de travailler sous irradiation LED a fait des progrès gratifiants. Ici, notamment l'azurant fluorescent en tant que classe de dérivés fluorophores, a été confirmé comme un Pl efficace pour la photopolymérisation radicalaire (FRP), l'un des principaux avantages est qu'ils peuvent travailler efficacement sous l'air, même à faible intensité lumineuse. Lorsqu'ils sont incorporés dans des systèmes photoinitiateurs multicomposants (en présence de sel d'iodonium (et éventuellement N-vinylcarbazole ou amine)), les dérivés du naphtalène-benzoxazole, des triazinylstilbènes sulfonés, du stilbène-biphényl sulfoné et du coumarinme inhibent d'excellentes capacités photoamorcantes pour la FRP des acrylates sous air. De plus, ils sont particulièrement efficaces pour la formation d'un réseau de polymères interpénétrés à travers une photopolymérisation cationique 1 radicale concomitante d'un mélange époxydes 1 acrylates.De plus, la substitution d'une certaine teneur en monomère acrylate avec de l'eau augmente positivement la conversion finale des fonctions acrylate polymérisables, spécialement formulée avec les systèmes initiateurs à base d'azurants hydrophiles. En outre, une formulation aqueuse d'acrylate contenant des systèmes d'amorçage à base d'azurants a permis la synthèse d'hydrogels assistée par LED. Cette méthode de synthèse consomme moins d'énergie et les hydrogels produits ont généralement une teneur élevée en eau. Et, l'étude des photopolymérisations qui se déroulent dans les mélanges acrylate 1 eau élargit les perspectives pour le polymère vert et la chimie organique. / The development of a new photoinitiator/photoinitiatng system being capable of strongly absorbing light in the visible-light region and working under LED irradiation has made gratifying advance. Herein, notably the fluorescent brightener as one class of fluorophore derivetives, has been confirmed as an efficient Pl for free radical photopolymerization (FRP), one of the major advantages is thalthey could efficiently work under air even exposure to a low LED light intensity. When incorporated into multicomponent photoinitiating systems (in the presence of iodonium salt (and optionally N-vinyl carbazole or amine)), the derivatives of naphthalene­ benzoxazole, sulfonated triazinylstilbenes, sulfonated stilbene-biphenyl and coumarinmexhibit quite excellent photoinitiating abilities for FRP of acrylates under air. Moreover, they are particularly efficient for the formation of interpenetrated polymer network through a concomitant cationic/radical photopolymerization of epoxides/acrylates blend.Additionally, substitution of a certain content of acrylate monomer with water is found to positively increase the final conversion of polymerizable acrylate functions, especially formulated with the hydrophilic brighteners-based initiating systems. Besides, an aqueous acrylate formulation containing brighteners-based initiating systems enabled the LED-assisted synthesis of hydrogels. This synthetic method is less energy-intensive and the hydrogels produced are typically of high water content. And, the investigation of photopolymerizations thal proceed in acrvlate/water blends broadens the perspectives for qreen polvmer and organic chemistry.

Supramolecular chemistry has asserted itself as a significant multidisciplinary field concerned with molecular effects afforded through non-covalent molecular interactions. The increased interest in the literature towards nanoscale devices, through modulation of molecular function, has seen the renaissance of supramolecular chemistry as function progresses from solution to surface. Heterosupramolecular chemistry follows the architectural principles of supramolecular chemistry and embraces both covalent and non-covalent interactions of condensed phase surfaces and molecular components. A modular approach to device architecture was applied as a novel method of performing photocatalysis under visible light illumination. The application of heterosupramolecular assembly to the design of photoelectrochemical cells capable of visible light induced charge separation allowed the study of interfacial processes by means of electrochemical observations. Preparation of a series of supramolecular components was undertaken as specific molecular species within a photochemical system. Starting from a synthesised bidentate ligand that incorporated an acidic functional group, 4,4'-bis(methyl)phosphonate-2,2'-bipyridine (dmpbpy) as its ethyl ester, was chelated to give the surface sensitisers, bis-(2,2'-bipyridine)-(4,4'-bis(methyl)phosphonato-2,2'-bipyridine)ruthenium(II) dichloride ([Ru(bpy)2(dmpbpy)]Cl2) and cis-bis-(4,4'-bis-(methyl)phosphonato-2,2'-bipyridine)(2,2'-bipyridine)ruthenium(II) dichloride ([Ru(dmpbpy)2(bpy)]Cl2). An electron relay moiety with an acidic functional group, 1-ethyl-1'-(2-phosphonoethyl)-4,4'-bipyridinium dichloride (EVP), was also prepared using a procedure developed by the candidate. The electronic properties of the prepared photosensitisers were examined by theoretical quantum chemical TD-DFT calculations on the molecular structures and singlet excitations were discussed in relation to experimental data. This identified that the lowest lying LUMO states were consistently occupied by 2,2'-bipyridine (bpy) and this was speculated to be a factor affecting quantum injection yields. The effect of microwave modification of colloidal TiO2 suspensions under extended periods of treatment was investigated. Nanoparticles of TiO2 were compared and contrast to similar convection hydrothermally treated TiO2 and a commercial titania product, namely Degussa P25, both of which are utilised in device fabrication. The investigation identified that extended periods of microwave hydrothermal treatment do not greatly enhance the crystallinity and primary grain size of TiO2. The heterosupramolecular assembly of a multi-component photochemical system was constructed from prepared molecular and condensed phase components. It was demonstrated that this device was capable of inducing a photochemical reaction in H2O under irradiation with  > 420 nm in the absence of an organic electron donor. Interpretation of the photocurrents obtained from this assembly provided understanding of photochemical reactions under low light intensities. Optimised conditions for the photochemical reaction was determined to be pH = 5 and illumination yielded = 0.0036% with an apparent quantum yield (AQY) = 1.6%. Photocatalytic decomposition of organic compounds in a dye-sensitised photoelectrocatalytic cell was investigated for the complete mineralisation of EDTA into CO2, H2 and simple amines and interpreted through photocurrent observations. This was extended to a broad range of organic compounds of various solution concentrations as a simulated industrial waste stream. Photooxidation gave unique photocurrent-time profiles which identified two distinct interfacial processes by mathematical treatment of photocurrent transients with a kinetic model. Kinetic parameters were proposed as a factor for qualitative discrimination of the organic compounds. The implications of these results for heterogeneous catalysis were discussed and the formation of Host-Guest complexes as a method of molecular sensing and as specific photocatalytic receptors was proposed.

Abstract In visible light communication (VLC), light emitting diodes (LEDs) are used as transmitters; the air is the transmission medium and the photodiodes are used for receivers. This is often referred to as light fidelity (Li-Fi). In this thesis, we provide the methodology to evaluate the performance of VLC hotspot networks in the context of data downloading on the move scenarios by using throughput-distance relationship models. In this context, first we study the different properties of optical transceiver elements, noise sources, characterization and modelling of artificial light interference, different link topologies and then we introduce the throughput-distance relationship model. Secondly, the analytically based throughput-distance relationship has been developed for evaluating the performance of VLC hotspot networks in indoor environment in both day and night conditions. Simulation results reveal that background noise has a significant impact on the performance of VLC hotspots. As expected, in both indoor and outdoor environments the VLC hotspot performs better at night than during day. The performance of VLC hotspot networks is also quantified in terms of received file size at different bit error rate requirements and velocities of the mobile user. Thirdly, we study the performance of hybrid (Radio-Optical) WLAN-VLC hotspot and compare its performance with stand-alone VLC-only or WLAN-only hotspot cases. In this case, we also consider the data download on the move scenarios in an indoor environment for a single-user as well as for multi-user cases. In this hybrid WLAN-VLC hotspot, both the WLAN and the VLC are characterized by their throughput and communication range. Simulations have been performed to evaluate the performance of such network for data downloading on the move scenario by taking into account performance metrics such as filesize, average connectivity and system throughput. Simulation results reveal that the considered hybrid WLAN-VLC performs always better than stand-alone VLC-only or WLAN-only hotspot both for a single and multi-user cases. Finally, this thesis analyses the feasibility and potential benefits of using hybrid radio-optical wireless systems. In this respect, cooperative communication using optical relays are also introduced in order to increase the coverage and energy efficiency of the battery operated device. Potential benefits are identified as service connectivity and energy efficiency of battery operated device in an indoor environment. Simulation results reveal that user connectivity and energy efficiency depend on user density, coverage range ratio between single-hop and multi-hop, relay probabilities and mobility of the user. / Tiivistelmä Näkyvään valoon pohjautuvassa tiedonsiirrossa (VLC) valodiodeja (LED) käytetään lähettiminä, ilma on siirtokanava ja valoilmaisimia käytetään vastaanottimina. Tätä kutsutaan usein nimellä light fidelity (Li-Fi). Tässä työssä tarjoamme menetelmiä VLC ”hotspot” verkkojen suorituskyvyn arviointiin tiedonsiirtonopeus-etäisyysmalleilla skenaarioissa, jossa tietoa ladataan liikkeessä. Tässä kontekstissa tutkimme ensin optisen lähettimen komponenttien eri ominaisuuksia, kohinan lähteitä, keinovalon häiriömalleja ja tiedonsiirtolinkkien topologioita, jonka jälkeen esittelemme tiedonsiirtonopeuden ja etäisyyden välisen mallin. Toiseksi kehitetyn analyyttisen tiedonsiirto-etäisyys mallia käytetään arvioitaessa VLC hotspot verkkojen suorituskykyä sisäympäristössä sekä päivä että yö olosuhteissa. Simulointien tulokset osoittavat, että taustakohinalla on suuri vaikutus VLC verkkojen suorituskykyyn. Kuten odotettua, sisä- ja ulkotiloissa VLC hotspot toimii paremmin yöllä kuin päivällä. VLC hotspot verkkojen suorituskyky arvioidaan myös vastaanotetun tiedoston koon, eri bittivirhesuhteen vaatimuksilla ja liikkuvan käyttäjän nopeuden suhteen. Kolmanneksi tutkimme hybridi WLAN-VLC hotspot verkon suorituskykyä ja vertaamme sen suorituskykyä pelkän VLC- tai WLAN hotspot tapauksessa. Käsittelemme myös skenaarioita jossa tiedoston lataus tapahtuu liikkeessä sisätilassa yhden käyttäjän sekä monen käyttäjän tapauksissa. Tässä hybridi WLAN-VLC hotspot, sekä erilliset WLAN- ja VLC verkot ovat määritelty niiden tiedonsiirtonopeuden ja kantaman perusteella. Näiden verkkojen suorituskykyä arvioitaessa on tehty joukko tietokonesimulointeja verkossa tapahtuvasta tietojen lataamisesta liikkeessä ottamalla huomioon suorituskyvyn mittarit kuten tiedoston koko, keskimääräinen yhteyden kesto ja saavutettu läpäisy. Simuloinnin tulokset paljastavat, että hybridi WLAN-VLC toimii aina paremmin kuin pelkkä VLC tai WLAN hotspot sekä yhden että monen käyttäjän tapauksessa. Lopuksi työssä analysoidaan ehdotetun järjestelmän toteutettavuus ja mahdolliset edut käytettäessä hybridejä radio-optisia langattomia järjestelmiä. Tältä osin esitellään myös kooperatiiviseen viestintään perustuvat optiset releet parantamaan verkon kattavuutta ja energiatehokkuutta akkukäyttöisissä laitteissa. Mahdolliset hyödyt tunnistetaan palvelun konnektiivisuudessa ja energiatehokkuudessa akkukäyttöisissä laitteissa sisätiloissa. Simulointien tulokset osoittavat, että käyttäjien konnektiivisuus ja energiatehokkuus riippuvat käyttäjätiheydestä, kantaman ja etäisyyden välisestä suhteesta yhden hypyn ja monen hypyn välillä, releointi todennäköisyydestä ja käyttäjien mobiliteetista.

De nos jours, le nombre d'appareils connectés nécessitant un accès aux données mobiles est en augmentation constante. L'arrivée d'encore plus d'ojects multimédias connectés et la demande croissante d'informations par appareil ont mis en évidence les limites de la quatrième génération de réseaux cellulaires (4G). Cela a poussé au développement de nouvelles méthodes, dont la 5G. L'objectif est d'être en mesure de prendre en charge la croissance des systèmes portables, des capteurs ou des sysèmes associés à l'internet des objets (IoT). La vision derrière la 5G est de permettre une société entièrement mobile et connectée avec une expérience consistente.Les petites cellules sont la base des normes de communication avancées telles que 4G et maintenant 5G. Ils résultent de l’utilisation de bandes de fréquences plus élevées pour l’accès radiofréquences (RF) afin de supporter de nouvelles normes et exigences croissantes en bande passante. La 5G utilise des ondes millimétriques et nécessite un déploiement dans un environnement urbain intérieur et urbain dense, ce qui peut s'avérer être un défi. C’est là que la 5G devra inclure des solutions de réseau hybrides et pouvoir coexister avec d’autres technologies d’accès sans fil. La communication par lumière visible (VLC) s’inscrit dans ce moule puisque la lumière visible correspond à la bande comprise entre 400 et 800 THz. Le spectre disponible est des milliers de fois plus large que le spectre RF et il n’interfère pas avec celui-ci. Le principe se base sur la combinaison de l'éclairage avec un lien de communication pouvant atteindre des dizaines de gigabits par seconde. Le potentiel est d’offrir un complément à la 5G dans un réseau hybride, offrant une vitesse élevée, aucune interférence et une sécurité accrue au prix d’une couverture limitée et d’une faible maturité technologique.L’objectif de cette thèse est donc de proposer et d’évaluer une implémentation expérimentale d’un système VLC en intérieur et multi-utilisateurs afin de répondre aux objectifs de la configuration light-fidelity (Li-Fi) dans le contexte d’une petite cellule. La première étape de cette étude est un état de l'art détaillé sur le principe de VLC dans la communication sans fil en intérieur et de l’accès multi-utilisateur. Cela permet de mieux expliquer le concept de notre désign et de comparer notre approche aux travaux existants. La deuxième étape consiste en une analyse des principes et des hypothèses pour le système VLC multi-utilisateurs en intérieur portant à la fois sur la technique de modulation et sur les schémas d’accès multi-utilisateurs. Les conclusions tirées des analyses théoriques et numériques servent de base pour la suite du travail. La troisième étape consiste en plusieurs analyses expérimentales sur l'optimisation des performances de diffusion pour un utilisateur unique, puis sur les performances multi-utilisateurs du système à l'aide de divers schémas d'accès. Le débit total avec une LED blanche commerciale atteint 163 Mb/s avec un taux d'erreur réduit d'un facteur de 3,55 grâce au processus d'optimisation des performances. Cette technique a l'avantage d'augmenter la flexibilité pour un scénario avec plusieurs utilisateurs sans augmenter la complexité car seuls les paramètres des filtres de modulation sont altérés. La taille de la cellule obtenue est de 4.56 m² à une distance de 2,15 mètres du transmetteur. Le capacité peut atteindre jusqu'à 40 utilisateurs, ou 40.62 Mb/s dans un scénario à 4 utilisateurs. Il est donc démontré que le système proposé pourrait fonctionner comme une cellule à une distance réaliste, avec un débit de données élevé et la capacité de répondre aux besoins d’un grand nombre d’utilisateurs tout en limitant les coûts de mise en œuvre. / Nowadays, the number of connected devices requiring access to mobile data is considerably increasing. The arrival of even more connected multimedia objects and the growing demand for more information per device highlighted the limits of the fourth generation of broadband cellular networks (4G). This pushed for the development of new methods, one of which is 5G. The goal is to be able to support the growth of wearable, sensors, or related internet-of-object (IoT) systems. The vision behind 5G is to enable a fully mobile and connected society with a consistent experience. In consequence, there is a fundamental need to achieve a seamless and consistent user experience across time and space.Small cells are the basis of advanced communications standards such as 4G and now, 5G. They exist as a result of using higher frequency bands for RF access in order to support new standards and the increasing demands in bandwidth. 5G use millimeter waves and requires a deployment across indoor and dense urban environment which may prove to be a challenge. This is where 5G will need to include hybrid networking solutions and be able to coexist with other wireless access technologies. Visible light communication (VLC) fits into that mold since visible light corresponds to the band between 400 and 800 THz. The available spectrum is multiple thousand times the size of the RF spectrum and it does not interfere with it. The technique combines illumination with communication at possibly tens of gigabits per second. It has the potential to offer a synergistic pairing with 5G in a hybrid network, offering high speed, no interferences, and more security at the cost of limited coverage and low technological maturity.The goal of this thesis is thus to propose and evaluate an experimental implementation of an indoor multi-user VLC system in order to answer the objectives of Li-Fi setup in the context of a small cell. The first step of this study is a detailed state-of-the-art on VLC in indoor wireless communication and multi-user access. It allows the design of our work to be better explained and to compare our approach with existing works. The second step is an analysis of the principles and hypothesis supporting the indoor multi-user VLC system in the study both on the modulation technique and the multi-user access schemes. The conclusions drawn from theoretical and numerical analysis are used as a basis for the rest of the work. The third step is the experimental setup investigations on the single-user broadcast performances optimization and then on the multi-user performances of the system using various schemes. The total throughput using an off-the-shelf white LED reaches 163 Mb/s with a bit-error rate decreased by a factor of 3.55 thanks to the performance optimization process. This technique has the advantage of increasing the flexibility for a multi-access scenario while not augmenting the complexity as it only optimizes the modulation filter parameters. The multi-user access is obtained for a cell size of 4.56 m² at a distance of 2.15 meter away from the transmitter. The user capacity can reach up to 40 users, or 40.62 Mb/s in a 4-user scenario. It is thus demonstrated that the proposed system could function as a cell at a realistic range, with high data rate and the ability to provide for a large amount of users while limiting the cost of implementation.

People around the globe are immensely trying to connect using light as carrier due to its low power consumption and high data transfer rates. Sound and microwaves are examples of other carriers that can be used, although they aren't nearly as efficient as light. A method of communicating is using light beneath the surface of the water. As the depth of the water increases, the temperature, pressure, and salinity of the water are changed. The refractive index of water is determined by the combination of all of these variable parameters. The goal of this thesis is to establish a relationship between changes in water temperature, salinity, and pressure resulting in changes of the refractive Index of the sea water. This thesis will demonstrate an empirical model of travelling the ultraviolet wave under sea water. We are acknowledging all of the properties that are change as the depth of the water is increasing. MATLAB was used to create a simulation of this scenario. Based on previous model of light traveling which covers the wavelengths between 400-700 nm, we have extended the model to ultraviolet range of light (200-400 nm).We design an experimental set up according to sea water parameters and then the experimental results are compared to the simulation results. The comparison shows the validity of our extension model.

Dans cette thèse, nous avons développé de nouveaux cadres d'analyse pour analyser et optimiser les futurs réseaux cellulaires à l'aide de la géométrie stochastique et des processus ponctuels. Cette thèse fournit quatre contributions techniques principales.Nous analysons d’abord les réseaux émergents capables de communiquer en utilisant la lumière plutôt que les ondes radio. Dans ce contexte, nous proposons un cadre analytique innovant qui nous permet d’estimer la probabilité de couverture et le débit moyen des réseaux distribués dans l’espace, qui sont utilisés pour mieux comprendre l’optimisation du système.Deuxièmement, nous proposons une méthodologie innovante pour modéliser des réseaux cellulaires spatialement corrélés en utilisant des processus ponctuels non homogènes. L'approche proposée est testée par rapport au déploiement pratique de réseaux cellulaires et s'est révélée pratique et précise. Il est appliqué à l'analyse des réseaux de communication à lumière visible et l'impact de la corrélation spatiale est étudié.Troisièmement, nous abordons le problème ouvert de la modélisation de réseaux cellulaires MIMO massifs. Nous étudions les réseaux cellulaires montants et descendants et proposons de nouvelles limites supérieures et inférieures pour l'efficacité spectrale moyenne, ce qui nous permet d'identifier le nombre optimal d'utilisateurs à desservir dans chaque cellule du réseau et l'impact de plusieurs paramètres clés du système.Quatrièmement, nous présentons et analysons les performances d'un nouvel algorithme de planification prenant en compte les interférences pour une application sur la liaison montante des réseaux cellulaires. L’approche proposée consiste à assourdir certains utilisateurs afin de réduire le niveau d’interférence. La performance réalisable et l'équité utilisateur de l'approche proposée sont discutées et quantifiées analytiquement. / In this thesis, we have developed new analytical frameworks for analyzing and optimizing future cellular networks with the aid of stochastic geometry and point processes. This thesis provides four main technical contributions.First, we analyze emerging networks that can communicate by using light instead of radio waves. In this context, we propose an innovative analytical framework that allows us to estimate the coverage probability and the average rate of spatially distributed networks, which are used to gain insight for system optimization.Second, we propose an innovative methodology for modeling spatially correlated cellular networks by using inhomogeneous point processes. The proposed approach is tested against practical deployment of cellular networks and found to be tractable and accurate. It is applied to the analysis of visible light communication networks, and the impact of spatial correlation is studied.Third, we tackle the open problem of modeling Massive MIMO cellular networks. We study uplink and downlink cellular networks and propose new upper and lower bounds for the average spectral efficiency, which allow us to identify the optimal number of user to serve in each cell of the network and the impact of several key system parameters.Fourth, we introduce and analyze the performance of a new interference-aware scheduling algorithm for application to the uplink of cellular networks. The proposed approach is based on muting some users in order to reduce the level of interference. The achievable performance and the user-fairness of the proposed approach are discussed and quantified analytically.

The photocatalytic wastewater treatment facility presented in this thesis is a promising economic green technology that can degrade wastewater’s organic and ammonia pollutants, which produce environmentally sensitive products like CO2, H2O, Nitrates, etc. that can be captured and used in many biological and engineering ways. Previous advances used for this research was determining the importance of cleaning the photocatalytic nanocrystals, Fe-TiO2, as one of the revolutionary improvements that expose and maximizes the active surface of the photocatalytic nanocrystals to the pollutants enabling the strong oxidants produced by the absorption of a photon, excitation of an electron and positive hole to produce oxidants on the surface of the nanocrystals. The oxidants indiscriminately produce CO2 and H2O from living and non-living organic matter to obtain near ~100% clean water. This research focused on taking the next steps in the development of a wastewater cleaning facility tested in our laboratory. An important step involved coating Fe-TiO2 crystals onto flexible, strong, fiber-glass cloth using a sol-gel processing method. Success was found in this research by applying the coated fiberglass cloth into a photoreactor aimed to clean a large amount of water rather than the laboratory scale. / Graduate

Visible light communication (VLC) is a novel complement to Radio Frequency Communication (RFC) and has many applications in wireless communication, indoor positioning and where RFC is not applicable. The problem is that the technology is black-boxed and therefore hard to apply in today’s design process. For designers to be able to use VLC in their creative process, this study uses the Inspirational Bits approach to expose the materiality of VLC by asking the question: How can we design artefacts that allow designers to engage in a conversation with Visible Light Communication as a material? Through Constructive Design Research, the technology was studied in iterations by building prototypes and reflecting on them. The prototypes are evaluated in two design workshops through observation and gathered feedback from 11 participants. As a result, seven artefacts were constructed to expose seven potential material properties of VLC. The observations and collected feedback show also that the artefacts help designers to gain tacit knowledge about VLC. The artefacts use the Arduino platform and standard electrical components. A by-product of this study is the "lumoino" toolkit for tinkering and prototyping with VLC. Eventually, strengths and weaknesses are discussed, and future work sections show the potential extensions of the artefacts and expansions of the toolkit. / ”Kommunikation med synligt ljus” (VLC) som ett design material är ett komplement till ”radio frekvens kommunikation” och har många applikationer inom trådlös kommunikation, Inomhuspositionering, och situationer där RFC inte är applicerbart. Problematiken med teknologi är att den ofta inte är synlig, och därför är svår att inkludera i dagens design processer. För att designers ska kunna använda sig av VLC i deras kreativa process, utgår denna studie från ”Inspirational Bits” förhållningsätt till design, och ämnar utforska följande frågeställning: Hur kan vi designa artefakter som tillåter designers att engagera sig i en konversation med ”kommunikation med synligt ljus” (VLC) som ett design material? Genom ”konstruktiv designforskning”, studerades prototyper av teknologin följt av analys. Processen upprepades med ett flertal modeller. Prototyperna utvärderades i två design-workshops, genom observation av och respons från 11 deltagare. Som resultat, byggdes sju stycken artefakter för att belysa sju stycken potentiella materiella egenskaper av VLC. Observationerna och den samlade responsen visade också att artefakterna hjälpte designers att få taktil kunskap om VLC. Artefakterna baserades på ”the Arduino Platform” och elektriska standard komponenter. En biprodukt av denna studie är ”the lumoino toolkit for tinkering and prototyping with VLC”. Eventuella styrkor och svagheter diskuteras och stycket framtida arbete visar potentiella utvecklingar och expantioner av ”the lumoino toolkit”.

Fotoredoxkatalys tillhandahåller möjligheter att utveckla nya hållbara kemiska reaktionsvägar. När fotokatalysatorn bestrålas med synligt ljus möjliggörs elektronöverföring till eller från substratet som i sin tur medför alstring av reaktiva fria radikaler. Kolradikaler, genererade med fotoredox-katalys från alkyloxalataktiverade alkoholer, har framgångsrikt kopplats till sulfinyliminer och möjliggör därigenom syntes av onaturliga α-aminosyror. Reaktionen utförs vid rumstemperatur och kräver endast extern energi i form av synligt ljus för att aktivera den iridium-baserade fotokatalysatorn. Den höga tillgängligheten av alkoholer utgör ett rimligt skäl för att använda dem som startmaterial. I detta projekt har tertiära alkoholer resulterat i framgångsrika reaktioner. / Photoredox catalysis provides opportunities to develop new sustainable chemical reaction pathways through single-electron transfer events and generation of reactive free-radical species. In this thesis carbon radicals, generated with photoredox catalysis from alkyl oxalate-activated alcohols, have successfully been coupled to sulfinyl imines and thereby enabling synthesis of unnatural α-amino acids. The reaction is performed at room temperature and only requires external energy in the form of visible light to activate the iridium-based photocatalyst. The abundance and availability of alcohols presents good reasons to use them as radical precursors. Under the developed reaction conditions, tertiary alcohols proved to be successful radical precursors, giving the desired product in good yield.

Heterojunctions were generated between tungsten trioxide and tetraphenyl porphyrin with reduced graphene oxide or exfoliated graphite support for mineralisation of acid blue 25 dye under visible light radiation. Moreover, degradation of pharmaceuticals was conducted using p-n heterojunctions between WO3 and Co3O4 and a direct Z-scheme heterojunction between BiOI and Co3O4 prepared using in-situ method and solvothermal self-assembly method respectively. The synthesized materials were characterised using Raman, FTIR, SEM/EDS, TEM, XRD, TGA, BET, UV-Vis and PL techniques. UV-Vis, TOC and HPLC-QTOF-MS were used to study the degradation efficiency and pathway. Scavenger trapping experiments were conducted to propose the charge transfer mechanisms. The highest degradation efficiency (99 %) was achieved for the dye and the pharmaceuticals using visible light. The mineralisation ability of the fabricated nanomaterials was pH dependent with acidic conditions favouring the removal of the dye (pH 5) while alkaline conditions favoured the mineralisation of pharmaceuticals (pH 10 – 11). / Civil and Chemical Engineering