Effect of the Agglomerated State on the Photocatalytic Hydrogen Production with in Situ Agglomeration of Colloidal TiO2 Nanoparticles

• DOI: 10.1021/jp808541v
• Publication Date: 2009-02-08T00:29:53Z
• Authors: Narayanan Lakshmi...; Wooyul Kim; Wonyong Choi
• Keywords: Photocurrent; Particle (ecology)

The photocatalytic production of H2 in aqueous TiO2 colloid (with methanol as an electron donor) was greatly accelerated by the situ agglomeration although such should reduce activity most other cases because reduction surface area. occurred after induction period 3 h and ascribed to pH increase which resulted from nitrate (incorporated synthetic step sol) ammonia. at close isoelectric point colloidal 6.9 measured ζ-potential. It is proposed that charge separation facilitated hopping particle when nanoparticles are connected with each within agglomerates. This behavior further supported photocurrent collection measurement (mediated methyl viologen MV2+/MV+ redox couple solution), also showed a rapid nanoparticles. When initially coagulated around 6, hydrogen increased linearly time without showing collected immediate upon irradiation. To understand role agglomerated state, (well-dispersed) suspension commercial (agglomerated) systems were compared discussed for their behaviors. present study demonstrates degree critical parameter determining efficiency production.