Natural tourmaline for pyroelectric dye decomposition under 25–60 °C room-temperature cold-hot fluctuation

Abstract

Tourmaline is a typical natural pyroelectric material. In this work, the pyroelectric property of tourmaline micro-powder is used to chemically deal with dyes wastewater under room-temperature cold-hot alternation. Under 25–60 °C heating-cooling cycles excitation, the decomposition ratio of Rhodamine B wastewater can achieve 84.7%. In the dye decomposition process, dissolved oxygen and hydroxide in the solution react with pyroelectrically induced positive and negative charges, respectively. This reaction triggers the production of superoxide radicals (O2–) and hydroxyl radicals (OH), which possess highly potent oxidation capabilities towards dye molecules. This work highlights the potential application of tourmaline mineral for dye decomposition in harvesting the environmental cold-hot alternation heat energy in future.