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A portable device to measure photocatalytic activity of materials

Scientists at the CSIC have developed a device called “pholouring” to instantly measure the photo-catalytic activity of materials. The device detects the photo-catalytic activity through probes and color indicators which are in contact with the analysed material. Virtually any material, either solid, liquid or a solution, can be tested.

The device ‘pholouring’ instantly measures the photo-catalytic activity of materials (CSIC).Current devices to measure activity of photocatalytic materials have some inconveniences: the results are not immediate, the equipment is quite expensive and their use requires technical staff. Also, the equipment cannot be adapted to every single physical and chemical structure, which makes impossible to analyze some materials. Altogether means that essays have to be done in laboratories, with specialized equipment and supervised by technical staff.

Scientists at the CSIC’s Instituto de Ciencias de la Construcción "Eduardo Torroja" have developed a portable and low-cost device which could overcome this problem. It is totally automated, it has a measuring system of colour-level and a lighting system, both connected  to a control unit.

What it does, basically, is this: the device’s light triggers the catalytic process and then it detects the formation of oxidizing molecules on the material’s surface, as these molecules are the responsible for the oxidation process of photocatalysis. The amount of oxidizing molecules is reflected by the probe, which changes its color.

The system can be applied either to solid materials – being the probe an stick-layer, for instance- or to liquids or dissolutions –then, the probe is liquid and the material to be analyzed is placed into the probe.  

This device is especially useful for testing construction materials. Eva Jimenez, a CSIC scientist at the Institute “Eduardo Torroja” explains that they receive in the research centre many requests from companies for testing materials, usually manufacturers that have added a photo-catalytic ingredient into the composition of a product (e.g., concrete, tiles).

The system can be applied either to solid materials – being the probe a stick– or to liquids or dissolutions –the probe is a liquid and the material to be analyzed is placed into the probe 

“We do this essays in our laboratory, each one of them requiring time and a minimum cost of 700 euros and up to 1000 euros sometimes. Often, the companies require several tests and results eventually show the product has not photocalalytic activity at all, which is a inconvenience for the manufacturer”.

This negative result can be due either because the mixture ingredients are not in the correct proportions or because the photocatalytic particles have degraded during the fabrication process, among other causes.

The new device could enable a preliminary test of the product in the factory, before requiring a more complex and expensive essay in a specialized laboratory and therefore reducing time and expenses.

Another interesting aspect is that the system can be adapted for permanent testing of materials which are already applied (on buildings, roads, walls…) using a USB connector or a battery. It would be the situation of any material that includes a photo-catalytic component for reducing pollution or self-cleaning and would allow the responsible for the facilities (city councils, for instance) to assess the effectiveness of the material. The system also tests parameters of the materials’s surface, such as porosity and roughness, which can influence on the final photo-catalytic activity.


Marisa Carrascoso Arranz
Área de Ciencias de Materiales
Vicepresidencia Adjunta
de Transferencia del Conocimiento (CSIC)
Tel.: + 34 – 91 568 15 33
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