Precise kinetic studies of photocatalytic reactions in solid
catalyst water suspensions require the accurate
description of the radiation fieldlight distributioninside the
reactor. Solution of the radiative transport
equation (RTE) inside the reaction is one of the best ways of accessing
to such information. For solving this
equation, a minimum of two parameters (the absorption and scattering
coefficients) and one scattering spatial
distribution function (the phase function) are needed. These
attributes are directly associated with the optical
behavior of the reacting system and are not independent of catalysts
more conventional properties. A complete
report on the physical and optical characteristics of titanium dioxide
particulate suspensions in water is
presented. Results were obtained for six different commercially
available powders. The investigated parameters
were (i) size of elementary particles, (ii) size of particle aggregates
in water suspensions, (iii) specific surface
area, (iv) spectral extinction coefficient, (v) spectral absorption
coefficient, and (vi) spectral scattering
coefficient. The last three were obtained as a function of
wavelength in the range 275−405 nm. All
measurements were made following a standardized protocol for the
preparation of the solid suspensions.
Scattering and absorption effects could be deconvoluted from the
extinction coefficient by applying a very
simple radiation transport model to the analysis of the experimental
data. Experimental information was
obtained by means of specially designed spectrophotometric measurements
made with conventional cells,
combined with results obtained with an integrating sphere accessory
operated in the transmission mode. These
propertiesparticularly the optical onesare required to solve the
RTE and (i) to calculate precise values of
photocatalytic reaction quantum yields and (ii) to fully characterize
radiation energy absorption effects in the
kinetics of photocatalytic reactions. Moreover, these data are
indispensable for devising scaleup procedures
in photocatalytic reactor design.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.