Real-time dynamic detection system for hydroxyl radicals produced by photocatalytic reaction

Abstract

The invention discloses a real-time dynamic detection system for hydroxyl radicals generated by photo-catalytic reaction. The real-time dynamic detection system comprises an excitation light source, a photo-catalyst and hydroxyl capturing probe storing container, at least one oxidant storing container, a detection pond, a photomultiplier and a signal analyzer host, wherein both the photo-catalyst and hydroxyl capturing probe storing container and the oxidant storing container are communicated with the detection pond; the photomultiplier is used for converting optical signals generated in the detection pond to electric signals; the photomultiplier is connected with the signal analyzer host; the signal analyzer host is connected with a computer terminal. A method for detecting by using the real-time dynamic detection system is simple to operate; the processes of separating samples offline and then detecting the sample online and the like are omitted, and therefore, the method is high in detection speed, capable of improving the working efficiency and applicable to quick screening and evaluation of hydroxyl-generating capability of a photo-catalytic material.

Description

technical field [0001] The invention relates to a real-time dynamic detection system for hydroxyl free radicals produced by photocatalytic reactions. Background technique [0002] Hydroxyl radicals (·OH) have a strong oxidizing ability (E=2.7 or 1.8V under acidic or neutral conditions), and can degrade almost all organic pollutants, so they have aroused great enthusiasm for research. In the natural environment, OH mainly comes from photo-Fenton reaction, nitrate and photolysis of natural organic matter (NOM). In the field of engineering, especially in the advanced oxidation technology (AOT), which has been continuously developed in recent years, such as Fenton reaction, ozone oxidation, electrolytic oxidation, etc., OH is the most important active substance and plays a decisive role in it. Therefore, it has also received extensive attention and in-depth research. At present, photocatalytic technology, as a new type of advanced oxidation technology, has aroused great resear...

AI Technical Summary

Problems solved by technology

However, the nature of OH is lively and short-lived (subtle level), and its determination is a great challenge

[0003] At present, the commonly used methods for measuring OH mainly include electron spin resonance technology (ESR) and fluorescent probe method, but these methods have their own limitations in practical applications, especially in the field of photocatalysis.

For example, currently the most commonly used capture probe for ESR is DMPO, but its capture specificity remains controversial

Photocatalytic materials will produce oxidation holes in the photocatalytic reaction. Some scholars believe that the adducts produced by the reaction between DMPO and oxidation holes are the same as the adducts of OH, which may lead to overestimation of photocatalytic materials. ·OH ability

Fluorescence is also a common method for measuring OH at present. Many probe molecules for OH determination have been developed, but the specificity of some probe molecules is still controversial.

In addition, when measuring the OH produced by photocatalytic reaction, their general operation process is to add the probe into the system to be tested first, take out a part after the reaction for separation, and then measure it on the machine, so the operation steps are cumbersome, which is not conducive to the detection of ·Quick and accurate determination of OH

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