Photocatalysts are materials that absorb sunlight and speed up chemical reactions. Some are used to cleanup wastewater. But though they're considered a "green technology," they're not always so eco-friendly.

The process of synthesizing materials like titanium dioxide (TiO2) and bismuth vanadate (BiVO4) -- used to clean water, break down dyes and kill bacteria -- is energy intensive. But a new production process promises to make these materials more efficient and environmentally friendly.

Instead of high temperatures and intense pressure, researchers in Thailand and Australia have found a way cook up BiVO4 using microwaves.

"These materials have a wide range of applications, but there has been little done to improve the way we make them," Jun Chen, a materials scientist at the University of Wollongong, in Australia, said in a press release. "People say photocatalysts are green, but sometimes the way we generate these materials is not really energy efficient."

The new production process happens at temperatures between 60 and 90 degrees Celsius, and takes only 16 minutes. Current methods take six hours.

The new microwave technology also offers scientists greater control over the formation of BiVO4 nanoparticles. Each particle is formed more uniformly. Controlling the precise shape and size of these nanoparticles allows scientists to build a material more efficient at encouraging the kind of chemical reactions necessary for cleaning water.

In tests, the newly produced BiVO4 was just as effective at breaking down a dye called Rhodamine B.

"We were so surprised that not many people are focusing on this area -- only a few studies have been done using microwaves," said Chen. "We hope this work will be of considerable interest to materials scientists who want to employ green technology to simplify the synthesis process for inorganic crystal materials."

The newly discovered microwave technology was detailed this week in the journal Materials Today.