A calibrated UV-LED based light source for water purification and characterisation of photocatalysis

Abstract

Photocatalysis has a potential to become a cost effective industrial process for water cleaning. One of the most studied photocatalysts is titanium dioxide which, as a wide band gap semiconductor, requires ultraviolet (UV) light for its photoactivation. This is at the wavelengths where the efficiency of present-day light emitting diodes (LEDs) decreases rapidly, which presents a challenge in the use of UV-LEDs for commercially viable photocatalysis. There is also a need for accurate photocatalysis measurement of remediation rates of water-borne contaminants for determining optimum exposure doses in industrial applications. In response to these challenges, this paper describes a UV-LED based photocatalytic test reactor that provides a calibrated adjustable light source and pre-defined test conditions to remove as many sources of uncertainty in photocatalytic analysis as possible and thereby improve data reliability. The test reactor provides a selectable intensity of up to 1.9 kW m at the photocatalyst surface. The comparability of the results is achieved through the use of pre-calibration and control electronics that minimize the largest sources of uncertainty; most notably variations in the intensity and directionality of the UV light emission of LEDs and in LED device heating.

The photocatalytic destruction of cinnamic acid and cinnamyl alcohol: Mechanism and the effect of aqueous ions

“…All experiments were conducted using the UV-LED based photocatalytic test reactor 14,15 developed as part of the EU funded PCATDES project that provides a calibrated adjustable light source and pre-defined test conditions to remove as many sources of uncertainty in photocatalytic analysis as possible and thereby improve data reliability.…”

Design and characterization of visible-light LED sources for microstructured photoreactors

“…Therefore, the irradiance was simulated on a parallel plane located at different z and D values by Eq. (12). Firstly, E(θ) extracted from NFGM is used and the model is denoted as model (NFGM).…”

“…Sergejevs et al designed a light source consisting of 36 UV-LEDs for the illumination of a catalyst surface in a batch reactor. 12 Series containing 3 LEDs were current driven and calibrated to account for the variability in the electrical and optical properties of the LEDs due to the manufacturing process. As 70% of the electrical power consumed by the LEDs was converted into heat, a temperature sensor and a liquid cooling system were used to avoid overheating of the printed circuit board (PCB).…”

The TiO2-ZnO Systems with Multifunctional Applications in Photoactive Processes—Efficient Photocatalyst under UV-LED Light and Electrode Materials in DSSCs

“…Therefore, considering using LED sources in photoactive processes, it is necessary to select an appropriate material. Hence, it should be noted that the focus on only one field (e.g., materials science) is insufficient [ 19 ].…”