Russian scientists develop high-efficiency solar catalysts that clean water using sunlight

Russia has developed a new class of photocatalysts which is capable of purifying water using visible sunlight. The method was created by scientists working at the Moscow Institute of Physics and Technology (MIPT), marking a breakthrough that could significantly advance sustainable water treatment, according to the official website of the institute.

The study, done by experts from MIPT's Centre for Photonics and Two-Dimensional Materials in collaboration with international scientists, identified an optimal material structure for high photocatalytic efficiency under visible light, as reported by TV BRICS.

Photocatalysis is considered a promising method for removing organic pollutants such as dyes, pharmaceutical residues, pesticides and oil traces from water. Most existing photocatalysts, however, rely mainly on ultraviolet light, which makes up nearly 5 per cent of the solar spectrum. By contrast, visible light accounts for nearly half of solar radiation, making its use crucial for scalable and sustainable purification technologies, according to TV BRICS.

What others method scientists use?

To address this limitation, scientists used femtosecond laser ablation in liquids, a method that involves ultra-short, high-energy laser pulses to vaporise a material's surfaces. The resulting vapour condenses into nanoparticles with tailored electronic characteristics. Crucially, this technique produces stable, water-based colloidal solutions without the need for surfactants, making the process both clean and environmentally friendly.

The scientists studied two niobium-based materials: niobium pentoxide (Nb₂O₅) and lithium niobate (LiNbO₃). Laser treatment affected them in distinct ways. Nb₂O₅ lost its crystalline order and became fully amorphous, whereas the more thermodynamically stable LiNbO₃ retained its crystal structure while developing controlled point defects.

Amorphous materials typically cause rapid recombination of light-generated charge carriers, limiting efficiency. In contrast, engineered defects within crystalline materials improve visible-light absorption and prolong charge-carrier lifetimes, allowing the formation of reactive species that more effectively degrade pollutants.