Enhanced photo-efficiency of immobilized TiO2 catalyst via intense anodic bias

Global environmental pollution is recognized as a serious problem that motivates the development of new technologies and mitigation of emissions from current ones. The civilian, commercial, and defense sectors of most advanced industrialized nations are facing problems related to remediation of hazardous wastes, contaminated soils and groundwater. In this communication, we describe results of a study indicating that the photo-efficiency of electrochemically grown porous TiO2-catalyst can be dramatically enhanced by an electrochemical approach that enables the development of a highly efficient water purification system. The dramatic efficiency enhancement of this process arises from deep understanding of the nature of TiO2-catalyst; intense and extreme electrochemical polarization would totally eliminates electron/hole pair recombination process, which is primary factor affecting photo-catalysis efficiency. Elimination of more than 99.9999% of Ecoli bacteria (5-6 orders of magnitudes of inactivation) within 6 h was achieved by the use of this approach. It was found that immobilized grown porous TiO2-catalyst can repeatedly be used, achieving extremely high efficiency, without any need for regeneration or highly advanced filtration techniques for the removal of the TiO2 such as in the powder technology. (C) 2007 Elsevier B.V. All rights reserved.