Polychromatic Irradiation Research Articles

Enhanced photoelectrocatalytic performance of direct Z-scheme CuWO4|TiO2 heterojunction for moxifloxacin oxidation

Films formed by the heterojunction of CuWO4 and TiO2 on conductive transparent substrate (fluorine-doped tin oxide - FTO) were utilized in moxifloxacin (MOX) degradation under polychromatic irradiation. The individual materials and the heterojunctions were systematically characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX), confirming the formation of heterojunctions from pure materials. Compared to the other configuration, the electrochemical characterizations showed higher photocurrent for FTO|CuWO4|TiO2 heterojunction, associated with better charge transport in the film. Thus, the photocatalytic activity of the FTO|CuWO4|TiO2 heterojunction was investigated for MOX degradation, which achieved an oxidation of 54.4 % of the drug in 150 min, employing the configuration electrochemically assisted heterogeneous photocatalysis (EHP). The efficiency of the heterojunction is about 2.5 times greater than that shown by electrodes formed from their individual materials. Radical scavenger studies showed that •OH radicals are the main species responsible for MOX oxidation process. The results of XPS, radical scavenging, photoelectrochemical, and photoelectrocatalytic activity show a charge transfer mechanism associated with a direct Z-scheme and that the FTO|CuWO4|TiO2 film is promising for the degradation of organic pollutants.

Doping of photoactive TiO2 films by DC plasma electrolytic oxidation: Effect of transition metals

Several beneficial features maintain TiO2 in the top list of viable materials for photocatalytic purposes. However, its relatively large band-gap (3.0–3.2 eV) still hampers practical applications under sunlight. This work explores Direct Current (DC) Plasma Electrolytic Oxidation (PEO) of titanium as a fast, easily-scalable and single-step tool to synthesise doped TiO2 photoanodes with controlled morphology, crystalline structure and thickness. Zn-, Cu- and Fe-doped crystalline TiO2 films were obtained in H2SO4 aqueous solutions containing ZnSO4, CuSO4 and FeSO4 precursors, respectively. As-prepared TiO2 films showed a porous and homogeneous sponge-like surface morphology, typical of PEO-produced oxides, and a crystalline phase structure consisting of a mixture of anatase and rutile phases. The anatase content varied in the 54–100 % range and correspondingly the band-gap energy was in the 2.85–3.07 eV range. Doped oxides prepared with a low concentration of the metal precursors showed monochromatic incident-photon-to-current-efficiency (IPCE) values exceeding those obtained with pristine TiO2 by up to 24 %, best performing in the order Zn- > Cu- > Fe-doped TiO2. Photocurrent under polychromatic UV-Vis irradiation showed an analogous trend and the estimated efficiency of solar-light harvesting was in the 0.3–4 % range, with Zn- ≈ Cu- > Fe-doped TiO2. Although the superior performance of the PEO-prepared metal-doped TiO2 could not be fully confirmed by photoelectrocatalytic oxidation tests of organics, the present investigation showed the viability of DC PEO for the synthesis of metal-doped TiO2 photoanodes.

On photokinetics under polychromatic light.

Since the dawn of photochemistry 150 years ago, photoreactions have been conducted under polychromatic light. However, despite the pivotal role that photokinetics should naturally play for such reactive photosystems, the literature lacks a comprehensive description of that area. Indeed, one fails to identify explicit model integrated rate laws for these reactions, a characteristic type for their kinetic behavior, or their kinetic order. In addition, there is no consensus in the community on standardized investigative tools to evaluate the reactivity of these photosystems, nor are there venues for the discussion of such photokinetic issues. The present work is a contribution addressing some of these knowledge gaps. It proposes an unprecedented general formula capable of mapping out the kinetic traces of photoreactions under polychromatic light irradiation. This article quantitatively discusses several reaction situations, including the effects of initial reactant concentration and the presence of spectator molecules. It also develops a methodology for standardizing actinometers and defines and describes both the spectral range of highest reactivity and the photonic yield. The validity of the model equation has been proven by comparing its results to both theoretical counterparts and those generated by fourth-order Runge-Kutta numerical calculations. For the first time, a confirmation of the -order character of the kinetics under polychromatic light was established.

Engineering anisotropic silver nanoparticles/TiO2 nanocomposites and its photodegradation process optimization under polychromatic light irradiation

AbstractIn this work, we engineered the functionalization of titanium dioxide (TiO2) with silver nanoparticles (AgNP) of different morphologies aiming the application of TiO2/AgNP nanocomposites as a smart photocatalytic material for environmental purposes. The characterizations confirmed TiO2‐Ag Schottky barrier formation, which allows the electron transfer process at the materials interface, increasing charge carriers lifetime. The photocatalysis process using methyl orange as a pollutant model in water and polychromatic Hg lamp was first maximized using factorial design statistics. Photodegradation kinetic evaluations showed that the nanocomposites were up to nine times more efficient than bare TiO2. The results show that dependence on AgNP size does not follow simple rules, while anisotropic AgNPs promoted higher efficiencies. Mechanism evaluation shows that photocatalysis occurred by three main routes: i) photoreduction of pollutant adsorbed on TiO2 surface; ii) reduction by radical superoxide; and iii) by hot electrons back injection on TiO2 conduction band. The effects ii and iii occurred preferentially at anisotropic nanostructures corners. In this scenario, photodegradation rates followed the order rod≥prisms>spheres. Therefore, this work systematic evaluated the influence of nanoparticle's morphology in the photocatalytic power of a TiO2/AgNP and points anisotropic AgNP‐functionalized nanocomposite as a promising nanomaterial for further environmental applications.

Crystalline S-doped TiO2 photoanodes from amorphous titanium oxysulfide (TiOxSy) for photo-oxidation reactions

S-doped TiO2 films were prepared by oxidation annealing of amorphous titanium oxysulfide (TiOxSy) at different temperatures. According to the X-ray diffraction patterns, the films calcined at temperatures of 300–600 °C showed only anatase phase, while the uncalcined sample was amorphous. The chemical composition of synthesized TiOxSy was estimated by X-ray photoelectron spectroscopy (XPS). High-resolution S 2p spectra showed S−2 bonds at 163.47 eV for the amorphous sample. The intensity of this signal decreased after heat treatment. Raman spectroscopy indicated an organization of the material structure with heat treatment of the material. Furthermore, optical characterization revealed that sulfur as dopant into the anatase TiO2 structure, shifted light absorption from ultraviolet to the visible region. Photoeletrochemical studies developed under polychromatic irradiation revealed superior photocurrents for samples calcined at 600 °C, with n-type behavior, adequate for photo-oxidation reactions.

Evaluation of disinfection efficacy of single UV-C, and UV-A followed by UV-C LED irradiation on Escherichia coli, B. spizizenii and MS2 bacteriophage, in water

Ultraviolet light-emitting diodes (UV LEDs) have shown ability to inactivate microorganisms and viruses in water. The unique characteristic of the UV-LEDs' diversity in wavelengths ranging from UV-C, UV-B, and UV-A, allows for wavelengths to be combined in different manners for polychromatic irradiation. Previous studies reported no synergy from simultaneous or sequential UV-C and UV-B as well as UV-C or UV-B followed by UV-A irradiation. However, synergy was reported for UV-A followed by UV-C or UV-B irradiation on various microorganisms. Nevertheless, no clear ground has been reached on whether to adopt single UV-C wavelengths or UV-A followed by UV-C LED, irradiation on inactivation of microorganisms and viruses in water. Therefore, this work evaluates the disinfection efficacy of single UV-C as well as UV-A followed by UV-C LED irradiation on Escherichia coli, Bacillus spizizenii spores and MS2 bacteriophage in water. The UV-C wavelengths were represented by 267 and 278 nm UV LEDs, and UV-A by 368 nm UV LEDs. In this study, E. coli was highly susceptible to UV radiation followed by B. spizizenii spores, and lastly MS2. Repair following UV inactivation was only observed in E. coli. The synergistic effect found in both E. coli, and B. spizizenii spores was attributed to the different inactivation mechanisms of the UV-C and UV-A wavelengths. In both single UV-C, and UV-A followed by UV-C LED irradiations, single 267 nm UV-C LED showed higher inactivation efficacy. Meanwhile, single 278 nm UV-C LED showed higher efficacy in terms of suppression of repair, and electrical energy consumption. Using single UV-C LEDs in a water disinfection system cuts down on related extra costs by avoiding combined wavelengths while still attaining better levels of microorganism inactivation, repair suppression and electrical energy consumption. These findings are applicable for the design and implementation of UV LED water disinfection systems.

Wavelength trends of photoproduction of reactive transient species by chromophoric dissolved organic matter (CDOM), under steady-state polychromatic irradiation

The formation quantum yields of photochemically produced reactive intermediates (PPRIs) by irradiated CDOM (in this study, Suwannee River Natural Organic Matter and Upper Mississippi River Natural Organic Matter) decrease with increasing irradiation wavelength. In particular, the formation quantum yields of the excited triplet states of CDOM (3CDOM*) and of singlet oxygen (1O2) have an exponentially decreasing trend with wavelength. The •OH wavelength trend is different, because more effective •OH production occurs under UVB irradiation than foreseen by a purely exponential function. We show that the parameter-adjustable Weibull function (which adapts to both exponential and some non-exponential trends) is suitable to fit the mentioned quantum yield data, and it is very useful when CDOM irradiation is carried out under polychromatic lamps as done here. Model calculations suggest that, thanks to the ability of CDOM to also absorb visible radiation, and despite its decreasing quantum yield of •OH generation with increasing wavelength, CDOM would be able to trigger •OH photogeneration in deep waters, to a higher extent than UVB-absorbing nitrate or UVB + UVA-absorbing nitrite.

Pyrazinamide photodegradation on NiWO4-palygorskite nanocomposites under polychromatic irradiation.

In this work, antibiotic pyrazinamide (PZA) photodegradation on palygorskite (Pal), NiWO4 crystals, and NiWO4-Pal (2, 6, and 10%) nanocomposites was evaluated under polychromatic irradiation. In the characterization of the samples, XRD patterns displayed good crystallinity for NiWO4 crystals and nanocomposites. In addition, the diffractograms were used in the Rietveld refinement for phase indexing, revealing a wolframite-type monoclinic structure with the space group P2/c. The active vibrational modes related to the characteristic groups of the samples were identified using Raman and FTIR spectroscopy. Photoluminescence (PL) spectra revealed that NiWO4 and NiWO4-Pal (2%) nanocomposite have the highest electron-hole pair recombination rate, and the contribution of the green component in the NiWO4-Pal (2%) nanocomposite indicates a greater contribution of deep energy levels to the PL profile. DRS in the UV-visible region indicated that NiWO4 crystals have indirect band-gap energy (Egap) 2.64 eV; NiWO4-Pal (2, 6, and 10%) nanocomposites have 2.62, 2.58, and 2.59 eV, respectively; and Pal has 2.83 eV. The catalytic tests showed that the NiWO4-Pal (2%) nanocomposite samples, under polychromatic radiation, exhibit greater efficiency in photodegradation at 110 min, with yield of 98.5%. The ROS tests indicated that the studied reactive species play a similar role in PZA photodegradation.

Wavelength effect on polymer photooxidation under LED weathering conditions

This paper is devoted to the investigation of the photooxidation of poly(N-vinylcarbazole (PVK) and polyethylene (LDPE) by exposure to λ ≥ 300 nm polychromatic light (SEPAP 12.24) or UV light produced by a new setup equipped with LEDs emitting at 365 nm (LED 365), both at a temperature of 60°C. Photooxidation was studied by infrared and UV-visible spectroscopies and emission spectroscopy in the case of PVK. The mechanisms by which the oxidation products were formed in both polymers were recalled. Depending on the conditions of ageing, i.e., polychromatic light or exposure to LED 365, the same oxidation products were obtained but with different rates and different relative amounts. This result reflected the influence of the wavelengths on the mechanisms. In the case of PVK, the formation of oxidation photoproducts and yellowing were not impacted, but the kinetics of the decrease in excimer fluorescence, which is linked to the crosslinking of the polymer, were dramatically modified. In the case of LDPE, wavelength effects on the photolysis of ketones by Norrish reactions were observed. As a consequence, irradiations with the LED 365 setup could not be claimed to be representative of polychromatic irradiations because the shortest wavelengths (300 nm < λ < 350 nm) were missing and could not reproduce natural outdoor conditions of weathering.

Photokinetics of Dacarbazine and Nifedipine under polychromatic light irradiation and their application as new reliable actinometers for the ultraviolet range

The photokinetic behaviour of drugs driven by polychromatic light is an area of pharmaceutics that has not received a lot of attention. Most often, such photokinetic data is treated by thermal kinetic models (i.e., the classical 0th-, 1st- or 2nd-order equations). Such models were not analytically derived from the rate-laws of the photodegradation reactions. Polychromatic light kinetic modelling is hence of importance, as a means to providing adequate toolkits and metrics. This paper aims at proposing two reliable drug-actinometers useful for polychromatic UVA range. The general actinometric methodology offered here is also useful for any drugs/materials obeying a primary photoprocess where both reactant and photoproduct absorb the incident light, of the AB{(1Phi )}_{{varepsilon }_{B}ne 0} type. The present method has been consolidated by the η-order kinetics. This framework further demonstrated the lamp-specificity of actinometers. Overall, Dacarbazine and Nifedipine photodegradations obeyed η-order kinetics, and stand as effective actinometers that can be recommended for the ICH Q1b photostability testing.

Wavelength Trends of Photoproduction of Reactive Transient Species by Chromophoric Dissolved Organic Matter (Cdom), Under Steady-State Polychromatic Irradiation

Wavelength Trends of Photoproduction of Reactive Transient Species by Chromophoric Dissolved Organic Matter (Cdom), Under Steady-State Polychromatic Irradiation

Enhanced photoelectrocatalytic performance of ZnO films doped with N2 by a facile electrochemical method

In the present study, we investigated the structural, morphological, photoelectrochemical, and photocatalytic properties of zinc oxide (ZnO) and ZnO films, which were prepared in the presence of nitrogen (N2) on fluorine-doped tin oxide (FTO)-conducting glass by electrodeposition and N2 bubbling for the doped films (Zn:N). The time, N2 flow, and calcination temperature conditions were investigated. X-ray diffraction (XRD) patterns show that ZnO and ZnO:N films have a wurtzite structure. X-ray photoelectron spectroscopy (XPS) analysis confirms nitrogen doped ZnO by both the interstitial and substitutional manners. Values at 3.25–3.27 eV of band gap energy of the films were estimated by the Tauc method. Field Emission Scanning Electron Microscopy (FE-SEM) images illustrated a change in the morphology of the ZnO:N film in relation to the ZnO film. Photoelectrochemical studies demonstrated a better photocurrent density for pure ZnO and ZnO:N films using a 20 cm3 min−1 flow rate treated at 500°C with ca. 48 and 70 µA cm−2 (0.7 V vs. Ag/AgCl), respectively. ZnO and ZnO:N electrodes (20 cm3 min−1) were used to degrade an aqueous 0.48 mg L−1 Rhodamine B (RhB) dye aqueous solution under polychromatic irradiation for 165 min. The degradation study was investigated under heterogeneous photocatalysis (HP) and electrochemically assisted HP (EHP) photocatalysis conditions. For RhB dye photodegradation, the performances obtained were 19% and 36% in HP for ZnO and ZnO:N, respectively. For the EHP configuration with a +0.7 V bias vs Ag/AgCl, the values were 26% and 43% for ZnO and ZnO:N, respectively. The studies presented here reveal that the N-doped ZnO films are promising candidates as photoanodes for photoelectrocatalysis applications.

Mono- and bimetallic (Pt/Cu) titanium(IV) oxide core–shell photocatalysts with UV/Vis light activity and magnetic separability

Titanium(IV) oxide is one of the most widely investigated photocatalysts. However, separation of nano-sized particulate titania might result in profitless technologies for commercial applications. Additionally, bare titania is almost inactive under the Vis range of solar spectrum due to its wide bandgap. Therefore, the present study aims to prepare novel core-interlayer-shell TiO2 magnetic photocatalysts modified with metal nanoparticles (Pt, Cu), which exhibit both photocatalytic and magnetic properties, making it easily separable within the magnetic field. Accordingly, the core–shell structure of Fe3O4@SiO2/TiO2 was obtained in water/TX100/cyclohexane microemulsion. Platinum and copper were photodeposited on four TiO2 templates and characterized by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), specific surface area (BET) measurement and diffuse reflectance spectroscopy (DR-UV/Vis). Photoactivity was studied in the reaction of phenol, acetic acid, and methanol degradation under UV/Vis irradiation, using both polychromatic and monochromatic irradiation (action spectrum analysis). The core-interlayer-shell structure of Pt and Cu modified magnetic photocatalysts was confirmed using scanning transmission electron microscopy (STEM). Magnetic photocatalysts modified with platinum and copper revealed improved photoactivity both in oxidation and reduction photocatalytic reactions, as compared to unmodified Fe3O4@SiO2/TiO2 photocatalysts. Finally, the correlation between physicochemical properties and photocatalytic activities of Fe3O4@SiO2/TiO2-Pt/Cu photocatalysts was investigated. For the first time, the effect of metals’ loading on the efficiency of phenol degradation and mineralization (TOC removal), and quantum efficiency of reaction in the presence of magnetic photocatalysts were analyzed. It was found that phenol can be efficiently decomposed (ca. 100%) during 60 min of UV/Vis irradiation for the photocatalyst recovered within the magnetic field during three subsequent degradation cycles.

Tailoring Nanoparticle Morphology to Match Application: Growth under Low-Intensity Polychromatic Light Irradiation Governs the Morphology and Optical Properties of Silver Nanoparticles

Silver nanoparticles (AgNPs) are incredibly versatile nanostructures that present a broad spectrum of applications, from nanomedicine to advanced optoelectronic materials. All AgNP properties stron...

Ni-Doped Titanium Dioxide Films Obtained by Plasma Electrolytic Oxidation in Refrigerated Electrolytes

Porous crystalline Ni-doped TiO2 films were produced using DC plasma electrolytic oxidation in refrigerated H2SO4 aqueous solutions containing NiSO4. The crystalline phase structure consisted of a mixture of anatase and rutile, ranging from ~30 to ~80 wt % rutile. The oxide films obtained at low NiSO4 concentration showed the highest photocurrent values under monochromatic irradiation in the UV-vis range, outperforming pure TiO2. By increasing NiSO4 concentration above a threshold value, the photoelectrochemical activity of the films decreased below that of undoped TiO2. Similar results were obtained using cyclic voltammetry upon polychromatic UV-vis irradiation. Glow discharge optical emission spectrometry (GD-OES) analysis evidenced a sulfur signal peaking at the TiO2/Ti interface. XPS spectra revealed that oxidized Ni2+, S4+ and S6+ ions were included in the oxide films. In agreement with photocurrent measurements, photoluminescence (PL) spectra confirmed that less intense PL emission, i.e., a lower electron-hole recombination rate, was observed for Ni-doped samples, though overdoping was detrimental.

Effect of the applied potential condition on the photocatalytic properties of Fe2O3|WO3 heterojunction films

Semiconductors heterojunction and potential application have been investigated as strategy to improve the catalytic processes performance. In this study, we investigated the photocurrent response of photoanodes composed of two different heterojunctions, i.e., Fe2O3|WO3 and WO3|Fe2O3, which were prepared directly on transparent and conductive glass substrate (fluorine-doped tin oxide or FTO-glass) by combining hydrothermal and drop-casting methods. From photoelectrochemical studies, the conduction band edge’s positions for each semiconductor were determined using the Butler–Gartner model. The heterojunction films were utilized as photoanode in photodegradation of Rhodamine B (RhB) dye in aqueous solution. Under polychromatic irradiation, superior performance was registered for FTO|WO3|Fe2O3 photoanode, reaching a RhB dye photodegradation around of 32% in 3 h. Moreover, we performed structural analyses, optical characterizations, and morphological property investigations using XRD, UV−Vis, and SEM techniques, respectively. Moreover, from the electrochemical studies, the superior photodegradation performance and photocurrent density for photoanode were registered for FTO|WO3|Fe2O3 film.

Hydroxyl and sulfate radicals activated by Fe(III)-EDDS/UV: Comparison of their degradation efficiencies and influence of critical parameters

In the present study, comparison of activation efficiencies of hydrogen peroxide (H2O2) and persulfate (PS, Na2S2O8) induced by Fe(III)-Ethylenediamine-N,N'-disuccinic acid (EDDS) under polychromatic irradiation UVA and visible region at same conditions was studied for the first time. The effects of pH, Fe(III)-EDDS concentration, H2O2 and PS concentrations were investigated. p-hydroxyphenylacetic acid (p-HPA) was taken as a model pharmaceutical intermediate pollutant to estimate the oxidative process efficiency. In these two systems, the degradation rate of p-HPA increased (not linearly) using higher concentrated solution of H2O2 and Na2S2O8. However, when Fe(III)-EDDS concentration exceeding 250 μM, the degradation efficiency of p-HPA began to decrease. Surprisingly, results of pH effects showed that Fe(III)-EDDS/H2O2/UV system presents much higher degradation efficiency than Fe(III)-EDDS/PS/UV whatever the solution pH’s, especially in neutral and alkaline solutions. In the Fe(III)-EDDS/H2O2/UV reaction, p-HPA degradation rate (Rp-HPA) increased fast from pH 2.5 to 7.5, then it began to decrease when pH increased to 9.0. While Rp-HPA started to decrease with pH increase to 3.9 in Fe(III)-EDDS/PS/UV system. To explain this phenomenon, the second order constant of p-HPA (for both molecular and mono-anionic forms) with HO and SO4− radicals were determined by laser flash photolysis (LFP) experiments for the first time. Results showed that kp−HPA,HO• was higher than kp−HPA,SO4•− for both anionic and molecular forms of pollutant. These results demonstrated that iron-complex induced photo-Fenton process is more efficient than activation of persulfate process, particularly at environmentally closed pH values and sun-simulated wavelengths (λ > 300 nm).

Photocurrent Response and Progesterone Degradation by Employing WO3 Films Modified with Platinum and Silver Nanoparticles.

The effect of silver (Ag0 ) and platinum (Pt0 ) metallic nanoparticles (NPs) on WO3 film was investigated by studying the photocurrent response under polychromatic irradiation. The structural phase revealed by X-ray diffraction analysis indicates a monoclinic crystal nanostructure. WO3, Ag0 /WO3, and Pt0 /WO3 electrodes were used to degrade 0.35 mg L-1 progesterone hormone in aqueous solution under polychromatic irradiation for 3h. The studies on degradation were investigated under electrochemically assisted heterogeneous photocatalysis (EHP) conditions. For photodegradation of progesterone, higher performance was achieved when WO3 was functionalized and when the EHP configuration was adopted with bias at +0.7 V vs Ag/AgCl. This study reveals that incorporation of metallic NPs onto a semiconductor increases its efficiency, thereby preventing electron-hole recombination in the photocatalyst and photoelectrochemical limitations of WO3 due to surface plasmon resonance and the trapping state. Therefore, efficient advances in the degradation of organic contaminants during water treatment can be realized.

A new source of ammonia and carboxylic acids in cloud water: The first evidence of photochemical process involving an iron-amino acid complex

In the present study we investigate the photochemical properties and impact on cloud water of ferric-aspartate complex (Fe(III)−Asp) under irradiation. Fe(III)−Asp complex was investigated as proxy of ferric-amino acids complexes that could be expected to be present in cloud water. First, the fate of complex under monochromatic (313 and 365 nm) and polychromatic (λ ≥ 290 nm) irradiation is investigated and formation quantum yields of Fe2+ are determined. Moreover, hydroxyl radical quantification in the presence of hydrogen peroxide is investigated at cloud water relevant concentrations and under irradiation. Obtained results suggest that hydroxyl radical formation rates are expected to be lower than those obtained considering all iron as aquacomplex or complexed with oxalate. Finally, a phototransformation mechanism for inorganic and organic products formation such as ammonia, malonic, oxalic and formic acids is proposed.

Photodegradation of brominated flame retardants in polystyrene: Quantum yields, products and influencing factors

Brominated flame retardants (BFRs) are widely used as additives in plastics, textiles and electronics materials. Here, we investigated the photodegradation of four BFRs including decabromobiphenylether (BDE-209), tetrabromobipsphenol A (TBBPA), tetrabromobisphenol A-bis(2,3-dibromopropylether) (TBBPA-DBPE) and tetrabromobisphenol A bis (allyl) ether (TBBPA-BAE). Experiments were carried out in polystyrene (PS) films using monochromatic and polychromatic irradiations. For comparison, irradiations were also carried in a solvent (tetrahydrofuran: THF). Monitoring of BFR degradation was performed using bulk and surface infrared (IR) measurements, as well as by extraction and HPLC-UV. Photoproducts were characterized using HPLC-high resolution electrospray ionization mass spectrometry (HPLC-ESI-Orbitrap-MS).All four BFRs underwent photochemical transformation in THF at 290 nm with a quantum yield (Φ) ranging from 0.05 for TBBPA to 0.27 for BDE-209, indicating an increase of photoreactivity with the number of Br atoms in BFRs. On the other hand, no major difference in the Φ values was observed when BFRs were embedded in PS films (Φ: 0.82–0.89). The higher photoreactivity in PS appears to be associated with a fast oxidation of PS as revealed by infrared (IR) analysis and yellowing of the films. Interestingly, the faster the yellowing occurred, the faster the BFR degradation was inhibited due to light screening effect. Several major photoproducts were identified for TBBPA and TBBPA-DBPE. Additional photoproducts possibly arising from PS oxidation and bromination by Br● were observed for the first time. This work provides a better understanding of the reactivity and fate of BFRs in polymers allowing for a better assessment of their environmental impacts.