Fast microwave synthesis of WO–WO/carbon particles for near infrared-driven photocatalytic water remediation

Photocatalytic water remediation is gaining much attention as a cost-efficient and environmentally friendly technology. We designed WO2.9–W18O49/carbon composite particles to overcome the drawbacks of semiconductor-based photocatalysts by extending light absorption capacity to the near-infrared region and achieving efficient charge separation. A 2.45 GHz microwave plasma successfully upgraded commercially available WO3 and polystyrene powders to the composite particles through a fast reaction with the typical heating and cooling rates of 30 and 470°C/s, respectively. The synthesized composite particles exhibited broad absorption in the UV-Vis-NIR range and outstanding electrical properties. Besides, excellent NIR-driven photocatalytic performance was demonstrated for the degradation of organic water pollutants (rhodamine B), with the WO2.9–W18O49 homojunction contributing to sufficient spatial charge separation, resulting in considerably enhanced degradation rates by more than two orders of magnitude.