Household Fluorescent Lamps Research Articles

High-performance triboelectric nanogenerator based on theoretical analysis and ferroelectric nanocomposites and its high-voltage applications

With the growing economy and technology, disease prevention and individual health are becoming more and more important. It is highly urgent to develop a non-toxic, self-powered, and safe high-voltage power source to prevent diseases spread by mosquitoes, especially in isolated or remote areas. Herein, we reported a high-performance rotary triboelectric nanogenerator (R-TENG) based on customized theoretical simulations and a ferroelectric nanocomposite intermediate layer. The customized theoretical simulations based on gradient electrode gaps were established to optimize gap angles and segment numbers of the electrodes, which could prevent air breakdown and enhance the R-TENG output energy by at least 1.5 times. Meanwhile, the electrical output performance of the TENG was further enhanced with a highly oriented BaTiO₃ (BTO) nanoparticles intermediate layer by about 2.5 times. The open-circuit voltage of R-TENG reached more than 6 kV and could continuously light 3420 LEDs or 4 serially connected 36 W household fluorescent lamps. Therefore, a self-powered high-voltage disease prevention system is developed based on the high-performance R-TENG to reduce the risk of disease transmission. This work provides a prospective strategy for the further development of TENGs and expands practical applications of self-powered and high-voltage systems.

Investigation of recycled fluorescent lamps waste as mineral filler in highway construction: A case of asphaltic pavement layers

Spent and discarded household fluorescent lamps are recognized as hazardous materials due to their contents of mercury and other pernicious components. The global-wide annual storage and dumping of millions of pieces of this electronic waste result in severe risks to arable land resources and give rise to ecosystem degradation and other environmental problems. A parallel issue is that the imminent depletion of those scarce raw materials used for road construction is now forcing highway administrations to seek sustainable resources. As such, the main purpose of this paper is to explore the feasibility of recycling fluorescent lamps into flexible pavement layers, namely the asphalt wearing and binder course, as an alternative to conventional mineral filler. To this end, a set of laboratory tests were conducted so as to compare and contrast mixtures incorporating recycled florescent lamp with control mixtures. These tests included the Marshall, indirect tensile stiffness modulus, wheel track, indirect tensile fatigue and dynamic creep test. Results demonstrate that the promising performance and cost-effectiveness of incorporating discarded fluorescent lamps into low to moderate traffic road surfaces can provide the pavement industry with new resource options.

Green Metal‐Free Photochemical Hydroacylation of Unactivated Olefins

Direct alkylation of C(sp2 )-H bonds to convert an aldehyde into a ketone is a notorious transformation, due to the laborious challenge of the formation of ketyl or acyl radicals. Herein, we report a green, cheap, metal-free and efficient method for the hydroacylation of olefins in water. This photochemical protocol utilizes phenylglyoxylic acid, a commercially available small organic molecule, as the photoinitiator, water as the solvent and household fluorescent lamps as the irradiation source, leading to a broad substrate scope of products in moderate to good yields. A wide range of aromatic and aliphatic aldehydes, terminal and non-terminal alkenes and pharmaceutically relevant molecules can be employed, without the need of directing groups and additives or metal catalysts.

Green Metal‐Free Photochemical Hydroacylation of Unactivated Olefins

AbstractDirect alkylation of C(sp2)−H bonds to convert an aldehyde into a ketone is a notorious transformation, due to the laborious challenge of the formation of ketyl or acyl radicals. Herein, we report a green, cheap, metal‐free and efficient method for the hydroacylation of olefins in water. This photochemical protocol utilizes phenylglyoxylic acid, a commercially available small organic molecule, as the photoinitiator, water as the solvent and household fluorescent lamps as the irradiation source, leading to a broad substrate scope of products in moderate to good yields. A wide range of aromatic and aliphatic aldehydes, terminal and non‐terminal alkenes and pharmaceutically relevant molecules can be employed, without the need of directing groups and additives or metal catalysts.

Photocatalytic decolorization of methylene blue by an immobilized TiO2 film under visible light irradiation: optimization using response surface methodology (RSM)

In this study, response surface methodology, based on face-centered composite design was used to investigate the effect of operational parameters on the decolorization of methylene blue (MB) using an immobilized film of TiO2 onto glass plate under a 55-W household fluorescent lamp irradiation. Three operating variables, namely TiO2 loading (0.65–3.9 mg/cm2), pH (2–10), and irradiation time (15–90 min) with a total of 20 individual experiments conducted to optimize the combination effects of the variable. The significance of the model and regression coefficients was tested by the analysis of variance. Analysis of the data obtained showed there was a strong significant influence of the operational factors and their interactions on MB color removal (p < 0.0001) of the photocatalytic decolorization process. The results predicted by the models were found to be in good agreement with those obtained by performing experiment (R2 = 0.9706 and Adj-R2= 0.9442). For MB color removal, the photocatalytic decolorization process was significantly influenced by the pH and irradiation time, whereas the TiO2 loading shows less effect. The optimum TiO2 loading, pH, and irradiation time were found to be 3.06 mg/cm2 (thickness = 42.43 ± 1.15 μm), 8.25 and 89.76 min, respectively. Under optimum conditions, high photocatalytic efficiency for MB color removal, 98.01% was observed. The kinetics of MB decolorization at optimum conditions was well fitted to the pesudo-first-order kinetic model.

ATRP with a light switch: photoinduced ATRP using a household fluorescent lamp

We report on photoinduced ATRP in solution and from surfaces using a standard fluorescent lamp as the light source.

Preparation and characterization of TiO2 coated with a thin carbon layer for enhanced photocatalytic activity under fluorescent lamp and solar light irradiations

Carbon (C) coated TiO2 with C content between 0.20% and 1.09% were prepared by calcination of various mixtures of TiO2 and epoxidized natural rubber (ENR-50) under N2 atmosphere between 470°C and 620°C. The optimum calcination temperature and C content was 560°C and 0.25±0.01%, respectively with the estimated C coating thickness of 0.68nm. The process did not change its BET surface area and induce any phase transformation. Photocatalytic activity of C coated TiO2 was better than pristine TiO2 for the degradation of anionic reactive red 4 (RR4) dye by more than 3 times, phenol by 1.1 times and cationic methylene blue (MB) by 1.5 times under a 45-W household fluorescent lamp irradiation while under solar irradiation, its photocatalytic activity with respect to pristine TiO2 improved by 5.5, 3.5 and 2 times, respectively. Coating of more than 1% C on TiO2 changed its photocatalytic activity either at par or less than that of the pristine TiO2. The observed photocatalytic improvement was due to the significant decrease in the electron–hole recombination process as observed for the optimum C coated sample.

A pilot-scale TiO2 photocatalytic system for removing gas-phase elemental mercury at Hg-emitting facilities

A pilot-scale TiO2 photocatalytic system using common household fluorescent lamps was tested at a real combustion facility for its ability to control Hg0 emissions. An Hg0 removal efficiency of greater than 90% was achieved under optimum conditions. The photocatalytic reaction units connected in series were more efficient than those connected in parallel. Acid components of the flue gas, such as NO and H2O, exhibited significant negative effects on the Hg0 removal efficiency. There was no difference in Hg0 removal efficiency between the systems employing mono-wavelength and tri-wavelength fluorescent lamps, and the efficiency was enhanced by increasing the amount of irradiation.

Enhancing visible-light-induced photocatalytic activity by coupling with wide-band-gap semiconductor: A case study on Bi2WO6/TiO2

The composites of different semiconductors based on the nanoscale coupling effect for photocatalytic application has been a challenging yet very important research topic. Bi2WO6 and TiO2, the two most extensively studied photocatalysts, were successfully coupled via a facile one-step hydrothermal process. The as-prepared Bi2WO6/TiO2 possessed enhanced visible-light-induced activity in photocatalytic degradation of contaminants in aqueous/gaseous phases compared with those of the sole Bi2WO6 or TiO2. The versatile Bi2WO6/TiO2 photocatalyst also exhibited long-time recyclable ability for the contaminants degradation under visible irradiation (λ>420nm) of Xenon lamp or household fluorescent lamp. The photoluminescence and electrochemical impedance spectroscopy are both adopted to analyze the physical properties of the photogenerated carriers and it was found that the separation of photogenerated carriers of Bi2WO6 has been largely promoted after being coupled with wide-band-gap semiconductor TiO2. This work could be extended to the design of other composite photocatalyst with the purpose of enhancing activity by coupling suitable wide and narrow band-gap semiconductors, which is inspiring for the practical environmental purification.

Free Radical Polymerization Initiated and Controlled by Visible Light Photocatalysis at Ambient Temperature

A new method of free radical polymerization is developed on the basis of visible light photocatalysis using Ru(bpy)3Cl2 that initiates and controls the polymerization at ambient temperature. The α-haloester and benzylic halide act as radical initiators that can be activated through the Ru(bpy)3+ photoredox cycle under visible light irradiation. Successful free radical polymerizations of various methacrylates were realized using a Xe arc lamp as well as a household fluorescent lamp as light source. The polymerization is initiated with light on and immediately terminated upon turning the light off. In addition, the molecular weight of polymer can be varied by changing the ratio of monomer and initiator. The present photocatalytic method has merits of the mild reaction conditions with weak light irradiation, ambient temperature, and lower catalyst loading, which could be an alternative to the traditional thermal or photo-based free radical initiation methods. It is also advantageous over other photopolymerization methods in that the radical initiator is separated from the photosensitizer.

Photocatalytic-oxidation of solid state chitosan by immobilized bilayer assembly of TiO 2–chitosan under a compact household fluorescent lamp irradiation

Photocatalytic-oxidation of an immobilized solid state chitosan (CS) by assembling a bilayer TiO 2–CS-glass system in aqueous solution under 45-W compact household fluorescent lamp was investigated. The structural and optical changes of CS were characterized by elemental analysis, Fourier-transform infrared spectroscopy (FT-IR) analysis, UV–vis diffuse reflectance spectroscopy (DRS) analysis and photoluminescence spectroscopy (PLS) analysis. The results indicated the formation of carbonyl side group and elimination of some amino group without altering much of the whole structure of CS. Furthermore, the photocatalytic-oxidation process led to the formation of an irregular surface morphology of CS according to the SEM images. The visual color changed to a more intense brown and less water uptake was also observed. The experimental results show that the bilayer TiO 2–CS-glass arrangement system can be considered as a convenient and environmentally friendly method for green chemistry application, especially in the field of the mild oxidation of a solid state CS.