Interfacial heterojunction construction by introducing Pd into W18O49 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-W18O49 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 W18O49 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 W18O49 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-W18O49 nanowires demonstrate enhanced photodegradation capacity in comparison with W18O49 nanowires. Especially, with Pd-W18O49 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-W18O49 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. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

A novel Pd-W18O49 nanowire photocatalyst was developed for high efficiency and stability in degrading methylene blue and neutral red under sunlight irradiation. The introduction of Pd reduced the band gap energy of W18O49 nanowires, facilitating electron transition and improving electron-hole separation, while also reducing electron-hole recombination. The Pd-W18O49 nanowires demonstrated enhanced photodegradation capacity compared to W18O49 nanowires, with significant decomposition of dyes observed within 40 minutes under sunlight.