3D-printed polymer substrate aids water purification

Photo Credit: Adobe Stock/michaelheim

It just makes sense that drinking water should be as pure and contaminant-free as possible, since clean and safe water is obviously essential for every human being. But even though access to clean drinking water should be a basic human right, an increasing number of regions face challenges with lack of drinking water resources, and not just in developing countries: North America and Europe also face challenges when it comes to drinking water, such as health concerns, contaminants, taste, environmental issues, and odour.

Which is why it’s good news that a research team from the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS) has developed a novel in-situ growing bismuth oxyiodide (BiOI) film on 3D-printed polymer substrate through successive ion layer adsorption reaction (SILAR) for water purification.

The researchers found that the substrate was completely covered with floriform microstructure film. They introduced OH^–/I substitution strategy to fabricate I-defects engineering BiOI film. The superficial colour of the 3D-printed substrates changed, in order, from gloss white to brownish yellow, dark yellow, and then light yellow – a change attributable to the change of band gap caused by iodine defect engineering film, the researchers said.

During the growing process of films, iodine spaces were introduced into the BiOI crystals, which increased the BiOI internal electric field and electron density and improved photoinduced carrier separation and transmission efficiency. Iodine defects engineering BiOI exhibited smaller grain size, higher specific surface area, electronegativity, photoelectric response, and photocatalytic activity than stoichiometry BiOI, the researchers said.

The researchers proposed that Bi³⁺ firstly adsorbed on polymers to construct the active grown sites of the film. With the extension of time, the films gradually self-assembled into petal-like BiOI film. High proportion and movement speed of I^– promoted the in-situ growth of BiOI film along the crystal plane.

“The film exhibits good photocatalytic activity and cyclic stability on photodegrading organic compounds and sterilizing microorganism,” said XU Xuelei, first author of the study.

This new water purification technology holds promise for providing efficient and sustainable solutions to address water pollution challenges, Xuelei continued.

Source: Chinese Academy of Sciences