Dr ‘Mope Malefane, a former student of the National University of Lesotho (NUL), is using tiny materials, called nanomaterials, and light…yes, mere light, to clean water! He has just graduated with PhD from the University of South Africa (UNISA).

‘Mope later published his amazing research work in the Journal ACS Omega (American Chemical Society), Volume 5, Issue 41, pages 26829–26844.

He started with two big troublemakers: p-nitrophenol, a chemical from pesticides, and brilliant black dye, a dark dye used in factories. These two love to stick around. They are toxic, stubborn, and very hard to remove once they get into water. You can leave them sitting in a bucket for days or even months, and they will still be there and be like, “Nice try, I’m not going anywhere.”
So ‘Mope knew he needed something powerful, fast, and clean; something that could break these pollutants apart all the way down to tiny pieces.

He needed something very, very small.

Something clever.

Something that almost feels like it came out of a sci-fi movie.

That “something” turned out to be nanomaterials; particles so tiny you could fit millions of them on the head of a pin. But ‘Mope wanted to mix three very special ones: Co₃O₄, Bi₄O₅I₂, and Bi₅O₇I. Each one had a special “superpower.”

One could catch visible light easily. Another was really good at making reactive particles. Another helped prevent electrons from wasting their energy too quickly. By themselves, each material was good. But together? They could become something much stronger.

To make this special blend, Mope first heated the bismuth-based materials until they changed into a mix of Bi₄O₅I₂ and Bi₅O₇I. These arrange themselves into tiny rods and sheets. Then he made cobalt oxide (Co₃O₄), which is great at helping reactions happen. Finally, he combined all three inside a sealed container that worked almost like a pressure cooker for chemistry.

When he looked at the result under a powerful microscope, he saw a beautiful mix of tiny rods, sheets, and particles woven together. It looked like a tiny team ready for action.

And action is exactly what happened when light hit them.

‘Mope poured polluted water into small beakers, added his nanomaterial, and switched on LED lights. Right away, the material “woke up.” Electrons jumped around. Tiny holes formed. Oxygen and water around the material suddenly turned into strong cleaning agents called reactive oxygen species. These microscopic radicals, especially hydroxyl radicals, are extremely strong. They grab onto pollutants and tear them apart piece by piece.

And wow…did they tear them apart.

In ‘Mopes experiments, p-nitrophenol dropped by 99.3% in just two hours, and brilliant black dropped by over 91% in three hours. These are chemicals that normally refuse to break down, yet his material handled them with ease.

Even better, he could reuse the same material many times and it still worked almost as well.
One of the reasons his material worked so well is because the three components inside it “talked” to each other. The electrons didn’t move randomly; they followed a curved path Mope called a C-scheme. This path kept the electrons and holes apart long enough for them to do real work, instead of wasting their energy. That meant more radicals were formed, and pollutants were destroyed much faster.

What made the idea even better is how simple it is.

No huge machines.

No heating.

No extra chemicals.

Just sunlight or LED light shining on ‘Mope’s nanomaterial, and the water becomes cleaner. It’s simple chemistry mixed with simple light, and some smart thinking from Lesotho.

This kind of idea can grow into something huge. Around the world, factories and farms release wastewater full of dyes, pesticides, and medicines. Most treatment plants can’t remove everything. But a photocatalyst, a material powered by light, can help break down the things that ordinary treatment systems miss.

Imagine factories shining LED lights on their wastewater before releasing it. Imagine villages using sunlight to clean small amounts of water. Imagine small solar-powered filters that destroy pollutants on the spot.

This is the future that Mope’s work points toward.