New Generation Energy-Efficient Light Source for Photocatalysis: LEDs for Environmental Applications

In this review, current progress in the area of photocatalysis using energy efficient Light Emitting Diodes (LEDs) as an irradiation source is discussed. LEDs are small in size, robust, do not contain mercury, have a longer life span than conventional light sources, and can operate on a direct current. These properties of LEDs offer a new alternative to traditional ultraviolet sources and open new possibilities for photocatalytic degradation with reduced power consumption, along with greater freedom in the design of various types of photocatalytic reactors. The present review mainly focuses on the photocatalytic degradation of organic compounds and dyes as well as the sterilization of microrganisms which are present in water and air, using irradiation by various types of LEDs, photocatalytic reactors, and catalysts. In addition, future prospects and challenges for the application of LEDs for to photocatalytic environmental pollutant degradation have been highlighted.

[1]  A. Fane,et al.  Evaluation of a submerged membrane vis-LED photoreactor (sMPR) for carbamazepine degradation and TiO2 separation , 2013 .

[2]  R. Jasra,et al.  Transition Metal Ion Impregnated Mesoporous TiO2 for Photocatalytic Degradation of Organic Contaminants in Water , 2006 .

[3]  M. Gholami,et al.  Apatite-coated Ag/AgBr/TiO(2) visible-light photocatalyst for destruction of bacteria. , 2007, Journal of the American Chemical Society.

[4]  W. Jo.  Photocatalytic Oxidation of Low-Level Airborne 2-Propanol and Trichloroethylene over Titania Irradiated with Bulb-Type Light-Emitting Diodes , 2013, Materials.

[5]  R. Ullah,et al.  Strategies of making TiO2 and ZnO visible light active. , 2009, Journal of hazardous materials.

[6]  P. K. Surolia,et al.  Effect of Anions on the Photocatalytic Activity of Fe(III) Salts Impregnated TiO2 , 2007 .

[7]  T. Scott,et al.  Sterilization of microorganisms on jet spray formed titanium dioxide surfaces , 2011 .

[8]  Luo Fan,et al.  Photodegradation of dyes in aqueous solutions containing Fe(III)-oxalato complexes , 1997 .

[9]  Demethylation of Acridine Orange by Arthrobacter globiformis , 1998, Bulletin of environmental contamination and toxicology.

[10]  R. Marandi,et al.  Ultraviolet Light-Emitting Diodes and Peroxydisulfate for Degradation of Basic Red 46 from Contaminated Water , 2011 .

[11]  Y. Ku,et al.  Photocatalytic degradation of Reactive Red 22 in aqueous solution by UV-LED radiation. , 2006, Water research.

[12]  K. Kümmerer,et al.  Biodegradability of the X-ray contrast compound diatrizoic acid, identification of aerobic degradation products and effects against sewage sludge micro-organisms. , 2006, Chemosphere.

[13]  M. Sillanpää,et al.  Photocatalytic degradation of dyes by CdS microspheres under near UV and blue LED radiation , 2013 .

[14]  P. Hanselaer,et al.  A batch LED reactor for the photocatalytic degradation of phenol , 2013 .

[15]  Anoop Verma,et al.  Photocatalytic degradation of Direct Yellow 12 dye using UV/TiO2 in a shallow pond slurry reactor , 2006 .

[16]  Elias Stathatos,et al.  Visible light-activated N-F-codoped TiO2 nanoparticles for the photocatalytic degradation of microcystin-LR in water ☆ , 2009 .

[17]  Qi Li,et al.  Self-organized nitrogen and fluorine co-doped titanium oxide nanotube arrays with enhanced visible light photocatalytic performance. , 2009, Environmental science & technology.

[18]  C. Liang,et al.  Facile synthesis of a surface plasmon resonance-enhanced Ag/AgBr heterostructure and its photocatalytic performance with 450 nm LED illumination. , 2013, Dalton transactions.

[19]  Richard D. Noble,et al.  Kinetics of the Oxidation of Trichloroethylene in Air via Heterogeneous Photocatalysis , 1995 .

[20]  J. Schoenung,et al.  Potential environmental impacts of light-emitting diodes (LEDs): metallic resources, toxicity, and hazardous waste classification. , 2011, Environmental science & technology.

[21]  Suja P. Devipriya,et al.  Photocatalytic degradation of pesticide contaminants in water , 2005 .

[22]  J. E. Boyd,et al.  Titania―Acrylic Coil Reactor for Photocatalytic Water Purification and Sterilization , 2009 .

[23]  R. G. Kulkarni,et al.  Photocatalytic Degradation of Aqueous Nitrobenzene by Nanocrystalline TiO2 , 2006 .

[24]  C. Xie,et al.  Low bias photoelectrocatalytic (PEC) performance for organic vapour degradation using TiO2/WO3 nanocomposite , 2011 .

[25]  M. Stylidi.  Pathways of solar light-induced photocatalytic degradation of azo dyes in aqueous TiO2 suspensions , 2003 .

[26]  G. Achari,et al.  Characterization of an LED based photoreactor to degrade 4-chlorophenol in an aqueous medium using coumarin (C-343) sensitized TiO2. , 2008, The journal of physical chemistry. A.

[27]  Y. Seto,et al.  Experimental Study on Adsorption and Photocatalytic Decomposition of Isopropyl Methylphosphonofluoridate at Surface of TiO2 Photocatalyst , 2010 .

[28]  Adriana Zaleska,et al.  Doped-TiO2: A Review , 2008 .

[29]  I. Maurin,et al.  Photocatalytic activity of mesoporous films based on N-doped TiO2 nanoparticles , 2010 .

[30]  Ling Zhang,et al.  The photocatalysis of Bi2MoO6 under the irradiation of blue LED , 2013 .

[31]  F. Kazemi,et al.  Photocatalytic reduction of aromatic nitro compounds using CdS nanostructure under blue LED irradiation , 2014 .

[32]  H. Bajaj,et al.  Energy Efficient UV-LED Source and TiO2 Nanotube Array-Based Reactor for Photocatalytic Application , 2011 .

[33]  Patrick Drogui,et al.  Modified TiO2 For Environmental Photocatalytic Applications: A Review , 2013 .

[34]  G. Achari,et al.  LED-Based Photocatalytic Treatment of Pesticides and Chlorophenols , 2013 .

[35]  K. Hashimoto,et al.  Comparison of photocatalytic properties of a batch reactor with those of a flow reactor in a nearly controlled mass transport region , 2005 .

[36]  R. W. Matthews,et al.  Photocatalytic oxidation of organic contaminants in water: An aid to environmental preservation , 1992 .

[37]  F. Akbal.  Photocatalytic degradation of organic dyes in the presence of titanium dioxide under UV and solar light: Effect of operational parameters , 2005 .

[38]  J. Emmett Duffy,et al.  Photocatalytic Oxidation as a Secondary Treatment Method following Wet Air Oxidation , 2000 .

[39]  K. Low,et al.  Removal of Some Organic Dyes by Acid-Treated Spent Bleaching Earth , 1999 .

[40]  G. Achari,et al.  A comparison of several nanoscale photocatalysts in the degradation of a common pollutant using LEDs and conventional UV light. , 2009, Water research.

[41]  J. Qu,et al.  Plasmon-induced inactivation of enteric pathogenic microorganisms with Ag-AgI/Al2O3 under visible-light irradiation. , 2010, Environmental science & technology.

[42]  G. Achari,et al.  Photocatalytic degradation of agricultural antibiotics using a UV-LED light source , 2014, Journal of environmental science and health. Part. B, Pesticides, food contaminants, and agricultural wastes.

[43]  Xiaoping Wang,et al.  Effect of hexamethylenetetramine on the visible-light photocatalytic activity of C–N codoped TiO2 for bisphenol A degradation: evaluation of photocatalytic mechanism and solution toxicity , 2011 .

[44]  P. Kamat,et al.  PHOTOCHEMISTRY OF TEXTILE AZO DYES. SPECTRAL CHARACTERIZATION OF EXCITED STATE, REDUCED AND OXIDIZED FORMS OF ACID ORANGE 7 , 1994 .

[45]  E. Thurman,et al.  Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999-2000: a national reconnaissance. , 2002 .

[46]  M. Sillanpää,et al.  Ultraviolet light emitting diodes and hydrogen peroxide in the photodegradation of aqueous phenol. , 2009, Journal of hazardous materials.

[47]  N. Yeh,et al.  Bactericidal effect of blue LED light irradiated TiO2/Fe3O4 particles on fish pathogen in seawater , 2011 .

[48]  Mika Sillanpää,et al.  Ultraviolet light-emitting diodes in water disinfection , 2009, Environmental science and pollution research international.

[49]  S. Martin,et al.  Environmental Applications of Semiconductor Photocatalysis , 1995 .

[50]  Yu-Ming Lin,et al.  Oxidation of aniline by titanium dioxide activated with visible light , 2012 .

[51]  Hang Zhou,et al.  Laboratory scale water circuit including a photocatalytic reactor and a portable in-stream sensor to monitor pollutant degradation , 2012 .

[52]  Mojtaba Safari,et al.  Photocatalytic degradation of methyl tert-butyl ether (MTBE) by Fe-TiO2 nanoparticles , 2013 .

[53]  Luhua Lu,et al.  Development of UV-LED/TiO2 Device and Their Application for Photocatalytic Degradation of Methylene Blue , 2013, Journal of Materials Engineering and Performance.

[54]  Xiang-Zhong Shen,et al.  Degradation of nitrobenzene using titania photocatalyst co-doped with nitrogen and cerium under visible light illumination. , 2009, Journal of hazardous materials.

[55]  K. Katayama,et al.  Reaction kinetics of dye decomposition processes monitored inside a photocatalytic microreactor. , 2012, Physical chemistry chemical physics : PCCP.

[56]  W. Choi,et al.  Photocatalytic Decomposition of H2O2 on Different TiO2 Surfaces Along with the Concurrent Generation of HO2 Radicals Monitored Using Cavity Ring Down Spectroscopy , 2012 .

[57]  C. Langford,et al.  UV- or Visible-Light-Induced Degradation of X3B on TiO2 Nanoparticles: The Influence of Adsorption , 2001 .

[58]  Daniel H. Chen,et al.  Oxidation of PCE with a UV LED Photocatalytic Reactor , 2005 .

[59]  Carole Rossi,et al.  Experimental Study of the Photocatalytic Degradation of Formaldehyde in Indoor Air using a Nano-particulate Titanium Dioxide Photocatalyst , 2007 .

[60]  C. Daughton.  Non-regulated water contaminants: emerging research , 2004 .

[61]  A. Fujishima,et al.  Electrochemical Photolysis of Water at a Semiconductor Electrode , 1972, Nature.

[62]  A. Fakhru’l-Razi,et al.  Review of technologies for oil and gas produced water treatment. , 2009, Journal of hazardous materials.

[63]  W. Jo,et al.  Feasibility of Light‐emitting Diode Uses for Annular Reactor Inner‐coated with TiO2 or Nitrogen‐doped TiO2 for Control of Dimethyl Sulfide , 2011, Photochemistry and photobiology.

[64]  J. Virkutyte,et al.  Evaluation of UV LEDs Performance in Photochemical Oxidation of Phenol in the Presence of H2O2 , 2010 .

[65]  P. K. Surolia,et al.  Enhanced Photocatalytic Activity by Silver Metal Ion Exchanged NaY Zeolite Photocatalysts for the Degradation of Organic Contaminants and Dyes in Aqueous Medium , 2008 .

[66]  Guiying Li,et al.  Photocatalytic inactivation of Escherichia coli by natural sphalerite suspension: effect of spectrum, wavelength and intensity of visible light. , 2011, Chemosphere.

[67]  M. Elimelech,et al.  Water and sanitation in developing countries: including health in the equation. , 2007, Environmental science & technology.

[68]  R. L. Sawhney,et al.  Treatment of Hazardous Organic and Inorganic Compounds through Aqueous-Phase Photocatalysis: A Review , 2004 .

[69]  Heechul Choi,et al.  Solar/UV-induced photocatalytic degradation of three commercial textile dyes. , 2002, Journal of hazardous materials.

[70]  Suresh Das,et al.  Photocatalytic degradation of waste water pollutants. Titanium dioxidemediated oxidation of a textile dye, Acid Blue 40 , 1997 .

[71]  Y. Ku,et al.  Effect of LED optical characteristics on temporal behavior of o‐cresol decomposition by UV/TiO2 process , 2007 .

[72]  M. Muneer,et al.  Semiconductor mediated photocatalysed degradation of an anthraquinone dye, Remazol Brilliant Blue R under sunlight and artificial light source , 2002 .

[73]  Andrew Mills,et al.  WATER-PURIFICATION BY SEMICONDUCTOR PHOTOCATALYSIS , 1993 .

[74]  H. Bajaj,et al.  Enhanced photocatalytic activity of bismuth-doped TiO2 nanotubes under direct sunlight irradiation for degradation of Rhodamine B dye , 2013, Journal of Nanoparticle Research.

[75]  Ammar Houas,et al.  Influence of chemical structure of dyes, of pH and of inorganic salts on their photocatalytic degradation by TiO2 comparison of the efficiency of powder and supported TiO2 , 2003 .

[76]  Lisha Zhang,et al.  Effective photocatalytic disinfection of E. coli K-12 using AgBr-Ag-Bi2WO6 nanojunction system irradiated by visible light: the role of diffusing hydroxyl radicals. , 2010, Environmental science & technology.

[77]  B. Liu,et al.  Microwave-assisted hydrothermal synthesis of monoclinic nitrogen-doped titania photocatalyst and its DeNOx ability under visible LED light irradiation , 2010 .

[78]  Julián Blanco,et al.  Photocatalysis with solar energy at a pilot-plant scale: an overview , 2002 .

[79]  Ivano G. R. Gutz,et al.  Microfluidic cell with a TiO2-modified gold electrode irradiated by an UV-LED for in situ photocatalytic decomposition of organic matter and its potentiality for voltammetric analysis of metal ions , 2007 .

[80]  V. Sharma,et al.  Occurrence, transportation, monitoring and treatment of emerging micro-pollutants in waste water — A review from global views , 2013 .

[81]  Wenzhong Wang,et al.  Highly efficient photocatalyst Bi2MoO6 induced by blue light-emitting diode , 2012 .

[82]  H. Bajaj,et al.  Study on UV-LED/TiO2 process for degradation of Rhodamine B dye , 2011 .

[83]  Y. Kaneko,et al.  High visible-light photocatalytic activity of nitrogen-doped titania prepared from layered titania/isostearate nanocomposite , 2007 .

[84]  Timothy N. Obee,et al.  Photooxidation of Sub-Parts-per-Million Toluene and Formaldehyde Levels on Titania Using a Glass-Plate Reactor , 1996 .

[85]  Huai-bing Wang,et al.  Sterilization system for air purifier by combining ultraviolet light emitting diodes with TiO2 , 2009 .

[86]  M Jekel,et al.  Application of GaN-based ultraviolet-C light emitting diodes--UV LEDs--for water disinfection. , 2011, Water research.

[87]  Liping Yang,et al.  Photocatalytic degradation of carbofuran in TiO2 aqueous solution: kinetics using design of experiments and mechanism by HPLC/MS/MS. , 2013, Journal of environmental sciences.

[88]  C. Namasivayam,et al.  Removal of copper(II) by adsorption onto peanut hull carbon from water and copper plating industry wastewater , 1996 .

[89]  S. B. Sawant,et al.  Photocatalytic Degradation of 2,4-Dichlorophenoxyacetic Acid Using Concentrated Solar Radiation: Batch and Continuous Operation , 2004 .

[90]  Young Ku,et al.  Photodecomposition of o-cresol by UV-LED/TiO2 process with controlled periodic illumination. , 2007, Chemosphere.

[91]  Jing Liu,et al.  Dimethyl Sulfide Photocatalytic Degradation in a Light-Emitting-Diode Continuous Reactor: Kinetic and Mechanistic Study , 2011 .

[92]  K. Thomas,et al.  Investigating the environmental transport of human pharmaceuticals to streams in the United Kingdom. , 2004, The Science of the total environment.

[93]  Je-Lueng Shie,et al.  Photodegradation kinetics of formaldehyde using light sources of UVA, UVC and UVLED in the presence of composed silver titanium oxide photocatalyst. , 2008, Journal of hazardous materials.

[94]  Shicheng Zhang,et al.  CFD modeling of a UV-LED photocatalytic odor abatement process in a continuous reactor. , 2012, Journal of hazardous materials.

[95]  G. Achari,et al.  Application of Photocatalysts and LED Light Sources in Drinking Water Treatment , 2013 .

[96]  Huijun Zhao,et al.  Synthesis and characterization of TiO2 nanotube photoanode and its application in photoelectrocatalytic degradation of model environmental pharmaceuticals , 2013 .

[97]  Y. Xiong,et al.  Photocatalytic activity of polymer-modified ZnO under visible light irradiation. , 2008, Journal of hazardous materials.

[98]  P. K. Surolia,et al.  Photocatalytic degradation of dyes and organic contaminants in water using nanocrystalline anatase and rutile TiO2 , 2007 .

[99]  Xiaoping Wang,et al.  Solvothermal synthesis of C–N codoped TiO2 and photocatalytic evaluation for bisphenol A degradation using a visible-light irradiated LED photoreactor , 2010 .

[100]  A. Morawski,et al.  Photocatalytic decomposition of azo-dye acid black 1 in water over modified titanium dioxide , 2002 .

[101]  Jiaguo Yu,et al.  Ion-Exchange Synthesis and Enhanced Visible-Light Photoactivity of CuS/ZnS Nanocomposite Hollow Spheres , 2010 .

[102]  D. Bahnemann,et al.  Photocatalytic Degradation of 4-Chlorophenol in Aerated Aqueous Titanium Dioxide Suspensions: A Kinetic and Mechanistic Study , 1996 .

[103]  B. Coulomb,et al.  Impact of watering with UV-LED-treated wastewater on microbial and physico-chemical parameters of soil. , 2013, Water research.

[104]  H. Bajaj,et al.  Photocatalytic Degradation of Methylene Blue Dye Using Ultraviolet Light Emitting Diodes , 2009 .