Metallic tungsten carbide nanoparticles as a near-infrared-driven photocatalyst

Abstract

Employing near infrared (NIR) light for photocatalytic reactions is preferable, considering effective solar utilization. Herein, the metalloid of tungsten carbide (WC) was used as an NIR-driven photocatalyst for the photodegradation of organic pollutants for the first time. The noble metal-like electronic properties of WC were proven via the analysis of its electronic occupied state using ultraviolet photoelectron spectroscopy and valence band XPS. In addition, both the experimental evidence and 3D finite element simulation revealed the NIR-responsive localized surface plasmon resonance (LSPR) behavior of the WC nanoparticles. Accordingly, the WC nanoparticles exhibited excellent UV-visible-NIR full-spectrum absorption, high NIR-triggered photocurrent response and resultant NIR-driven photocatalytic degradation performance. The NIR-mediated photocatalytic mechanism of WC was proposed based on a radical scavenging test, fluorescence observation of radical generation and spin-trapping electron paramagnetic resonance measurements. Hence, metallic WC with NIR absorption and photocatalytic activity may pave the way for the design of full-solar-spectrum-responsive photocatalysts.