Construction of a multipurpose photochemical reactor with on-line spectrophotometric detection

Abstract

A versatile photoreactor was built for studying homogeneous and heterogeneous photochemical reactions using fiber-optic devices. The reactor was designed to allow simultaneous photochemical initiation and online spectrophotometric monitoring of the reaction using independently controlled excitation and detection lamps. The system consists of a CCD spectrophotometer, a thermostated sample holder, two light sources, and standard 1.00 × 1.00 cm (or possibly smaller) fluorescence cuvettes, all coupled with fiber optic cables. The device can be used as a photoreactor, a diode-array spectrophotometer and also as a spectrofluorimeter. The reactor can be used in flow-through operation modes. Performance tests of the instrument are reported here with a number of known photochemical systems.

A versatile method for the determination of photochemical quantum yields via online UV-Vis spectroscopy

“…19 It has to be justified that the LED light passing through the cuvette does not deteriorate the detection of the UV-Vis spectra. 24 Nevertheless some scattered light may reach the detector. However, spectra usually show no distortion at the LED peak wavelength.…”

A detailed kinetic study of the direct photooxidation of 2,4,6-trichlorophenol

“…The solution in the cuvette was stirred using a 4 mm  2 mm  2 mm Teflon-coated stirring rod with the built-in magnetic stirrer of the sample holder to keep the solutions homogeneous at all times. The detailed description and performance characterization of this novel photoreactor was published in a recent technical note [30].…”

The pore network and the adsorption characteristics of mesoporous silica aerogel: adsorption kinetics on a timescale of seconds

“…6 and S4 is probably due to the unique positioning of the collimator lenses in the Avantes fiber-optic spectrophotometer. 37 In accordance with Beer's law, the absorbance at the instance of mixing MB and the aerogel is given by: First, the initial rate (v 0 ) was determined as a function of initial MB (c MB ) and aerogel (c gel ) concentrations (Figs. S5A and S5B in the Supporting Information).…”

“…The specifications of the instrument are detailed elsewhere. 37 The detector was typically operated with 15 ms integration time and 20 -50 subsequent spectra were averaged for smoothing. In these experiments, steady absorbance decay was detected, which was attributed to the depletion of the dye from solution due to adsorption on aerogel.…”