Interfacial heterojunction construction by introducing Pd into WO nanowires to promote the visible light-driven photocatalytic degradation of environmental organic pollutants.

Photocatalytic degradation of organic dyes by sunlight can greatly simplify the catalytic devices and save the cost. The development of photocatalysts for organic pollutants degradation driven by sunlight at room temperature still faces serious challenges. In this work, we developed a novel Pd-WO nanowire photocatalyst for high efficiency, high stability, and sunlight-induced degradation of methylene blue and neutral red. It was found that after Pd introducing, the band gap energy of WO nanowires lowers from 2.77 to 2.44 eV, which can accelerate the electron jump from the valence band to the conduction band, resulting in the efficient separation of electrons and holes. Meanwhile, with Pd introducing to the WO nanowires, interfacial heterojunction with the Schottky barrier is formed, which can reduce the rate of electron-hole recombination. The catalytic results show that the obtained Pd-WO nanowires demonstrate enhanced photodegradation capacity in comparison with WO nanowires. Especially, with Pd-WO nanowires (10 mg) as photocatalyst, 98.4% of methylene blue and 96.1% of neutral red can be decomposed within 40 min under sunlight irradiation. Besides, the photocatalytic degradation pathways of methylene blue and neutral red on the Pd-WO nanowires are also proposed. This study provides a good strategy for the design and preparation of highly efficient 1D heterojunction-based photocatalysts for the degradation of environmental organic pollutants.