Performance analysis and methodology for replacing conventional lamps by optimized LED arrays for photocatalytic processes

Tapia-Tlatelpa, Tecilli; Buscio, Valentina; Trull, J.; Sala, Vicent

doi:10.1016/j.cherd.2020.02.023

Cited by 18 publications

(16 citation statements)

References 43 publications

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“…Analyzing the effect of the irradiation source, a higher conversion was obtained when using the laser irradiation lamp (406 nm) in comparison with the argon lamp (467 nm) in both substrates studied. It is well known that laser irradiation sources improve the photochemical processes by reducing the effects of conventional lamps, such as those associated with long-term power stability due to overheating during operation, low photonic efficiency and longer exposure time [59][60][61][62][63]. This higher conversion obtained in the presence of laser radiation at 406 nm is also attributed to the proximity of this irradiation source to the absorption band associated to the ligand-metal transitions at 403 nm observed in the solid-state UV spectrum presented in figure S3 y S4 in supporting information (SI).…”

Section: Liquid-phase Photo-epoxidation Of (α β)-Pinenementioning

confidence: 99%

Photo-epoxidation of (α, β)-pinene with molecular O2 catalyzed by a dioxo-molybdenum (VI)-based Metal–Organic Framework

Castellanos

Ortega

et al. 2021

Res Chem Intermed

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A gallium-based metal-organic framework, post-modified with MoO 2 Cl 2 , was examined as a catalyst for the room temperature liquid-phase photooxidation of α-and β-pinene in the presence of molecular oxygen as the oxidant. For both substrates, (α, β)-pinene oxide was formed as the sole product due to the oxygen atom transfer process. Peroxo-molybdenum species was identified in the reoxidation process using infrared spectroscopy. Moreover, a comparison of the structure of the catalyst before and after catalysis by means of X-ray powder diffraction (XRPD), infrared spectroscopy (IR) and N 2 adsorption-desorption measurements demonstrated the high recyclability and potential of this catalyst in the photocatalytic epoxidation process of terpenes.

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Section: Liquid-phase Photo-epoxidation Of (α β)-Pinenementioning

confidence: 99%

Photo-epoxidation of (α, β)-pinene with molecular O2 catalyzed by a dioxo-molybdenum (VI)-based Metal–Organic Framework

Castellanos

Ortega

et al. 2021

Res Chem Intermed

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“…The development of ultra-violet light-emitting diodes (UV-LEDs) and recent advances in their wall-plug efficiency and affordability has opened up new possibilities for photocatalysis, since many features of UV-LEDs give them an upper hand in comparison to traditional low-or middle-pressure Hg UV lamps [32]. LEDs are built from durable ceramic materials, are mercury-free, have longer lifetimes, and have no required warm-up periods (which allows the use of photonic efficiency techniques, such as controlled periodic illumination (CPI)) [33].…”

Section: Introductionmentioning

confidence: 99%

“…LEDs are built from durable ceramic materials, are mercury-free, have longer lifetimes, and have no required warm-up periods (which allows the use of photonic efficiency techniques, such as controlled periodic illumination (CPI)) [33]. Their dimensions can be approximated as point sources, allowing very flexible design and small-scale point of use applications [32,34,35]. Previous studies highlighted the fact that the development of UV-LEDs is still very recent, so the technology is at an early stage [35,36].…”

Section: Introductionmentioning

confidence: 99%

“…Lower external quantum and wall-plug efficiencies, especially for lower wavelengths, were always considered the main hurdle for further adoption of UV-LEDs in the last decade [33]. Nevertheless, a recent review shows that E EO values of UV-LEDs and Hg UV mercury lamps are on the same order of magnitude [32] and comparisons between them are now feasible.…”

Section: Introductionmentioning

confidence: 99%

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Performance of TiO2/UV-LED-Based Processes for Degradation of Pharmaceuticals: Effect of Matrix Composition and Process Variables

et al. 2022

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Ultra-violet light-emitting diode (UV-LED)-based processes for water treatment have shown the potential to surpass the hurdles that prevent the adoption of photocatalysis at a large scale due to UV-LEDs’ unique features and design flexibility. In this work, the degradation of five EU Watch List 2020/1161 pharmaceutical compounds was comprehensively investigated. Initially, the UV-A and UV-C photolytic and photocatalytic degradation of individual compounds and their mixtures were explored. A design of experiments (DoE) approach was used to quantify the effects of numerous variables on the compounds’ degradation rate constant, total organic carbon abatement, and toxicity. The reaction mechanisms of UV-A photocatalysis were investigated by adding different radical scavengers to the mix. The influence of the initial pH was tested and a second DoE helped evaluate the impact of matrix constituents on degradation rates during UV-A photocatalysis. The results showed that each compound had widely different responses to each treatment/scenario, meaning that the optimized design will depend on matrix composition, target pollutant reactivity, and required effluent standards. Each situation should be analyzed individually with care. The levels of the electrical energy per order are still unfeasible for practical applications, but LEDs of lower wavelengths (UV-C) are now approaching UV-A performance levels.

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“…The application of UV-LEDs offers an alternative solution for the excitation of photocatalysts and has been employed for heterogeneous photocatalysis in recent years [ 20 , 22 , 23 ]. It is challenging to find the best design for photoreactors, such as optimizing the distribution and number of LEDs and light intensity [ 24 ].…”

Section: Introductionmentioning

confidence: 99%

Impact of Reaction Parameters and Water Matrices on the Removal of Organic Pollutants by TiO2/LED and ZnO/LED Heterogeneous Photocatalysis Using 365 and 398 nm Radiation

2021

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In this work, the application of high-power LED365nm and commercial, low-price LED398nm for heterogeneous photocatalysis with TiO2 and ZnO photocatalysts are studied and compared, focusing on the effect of light intensity, photon energy, quantum yield, electrical energy consumption, and effect of matrices and inorganic components on radical formation. Coumarin (COU) and its hydroxylated product (7-HC) were used to investigate operating parameters on the •OH formation rate. In addition to COU, two neonicotinoids, imidacloprid and thiacloprid, were also used to study the effect of various LEDs, matrices, and inorganic ions. The transformation of COU was slower for LED398nm than for LED365nm, but r07-HC/r0COU ratio was significantly higher for LED398nm. The COU mineralization rate was the same for both photocatalysts using LED365nm, but a significant difference was observed using LED398nm. The impact of matrices and their main inorganic components Cl− and HCO3− were significantly different for ZnO and TiO2. The negative effect of HCO3− was evident, however, in the case of high-power LED365nm and TiO2, and the formation of CO3•− almost doubled the r07-HC and contributes to the conversion of neonicotinoids by altering the product distribution and mineralization rate.

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Performance analysis and methodology for replacing conventional lamps by optimized LED arrays for photocatalytic processes

Cited by 18 publications

References 43 publications

Photo-epoxidation of (α, β)-pinene with molecular O2 catalyzed by a dioxo-molybdenum (VI)-based Metal–Organic Framework

Photo-epoxidation of (α, β)-pinene with molecular O2 catalyzed by a dioxo-molybdenum (VI)-based Metal–Organic Framework

Performance of TiO2/UV-LED-Based Processes for Degradation of Pharmaceuticals: Effect of Matrix Composition and Process Variables

Impact of Reaction Parameters and Water Matrices on the Removal of Organic Pollutants by TiO2/LED and ZnO/LED Heterogeneous Photocatalysis Using 365 and 398 nm Radiation

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