Adjusting the Energy Bands of WO₃@ZnO Nanocomposite Heterojunction Through the Combination of WO₃ Thin Film to Improve its Photoelectric Performance

Abstract

At present, nanomaterials with high-quality photoelectric properties are urgently needed to be used in the manufacture of solar cells. In this study, the hydrothermal synthesis method was first used to grow ZnO nanorod arrays, and then a layer of WO 3 thin film with controllable thickness was prepared on ZnO nanorod arrays by magnetron sputtering, forming a series of WO 3 @ZnO nanocomposite heterojunction. We found that the value of the photocurrent of the prepared nanocomposite samples is nearly 30 times higher than WO 3 films under illumination, and it is more stable. The results show that this controllable microstructure can further modify the surface properties of ZnO nanorods, and possess the high visible absorption and photoelectric conversion efficiency. By controlling the thickness of the WO 3 film, the band can be regulated and ultimately optimized the photoelectrochemical properties of the composite structure. INDEX TERMS: WO 3 @ZnO nano-heterostructures; hydrothermal method; magnetron sputtering; photoelectric; band regulation Recently, there have been extensive studies on the photoelectric performance of WO 3 , which have a bearing on solar energy utilization and photocatalytic. In recent years, the appearance of nano-structured tungsten oxide materials has a great impact on the research in the above fields. At present, many forms of WO 3 materials have been prepared, such as nanoparticles, nanotubes, nanosheets, nanorods and nanowires, etc [21-26]. There are many methods for preparing WO 3 thin films, including electrochemical deposition, magnetron sputtering, sol-gel, hydrothermal synthesis, and the like [27,28]. However, the photoelectric performance of the various shapes of pure WO 3 is still limited. According to the analysis reports, compositing other materials is a valid method for electronhole pair separation. If the semiconductor materials are combined with other semiconductors to constitute a special

One-Step Dry Coating of Hybrid ZnO–WO3 Nanosheet Photoanodes for Photoelectrochemical Water Splitting with Composition-Dependent Performance

“…First, ZnO samples were prepared within a reservoir using a 3 h thermal treatment at 550 • C. Second, ZnO was mixed with the WO 3 layers under optimized conditions: pressure = 0.3 M bar and RF power = 20 W for 3 h. The obtained ZnO-WO 3 composites achieved a 0.055 mA•cm −2 photocurrent at 0.8 V vs. Ag/AgCl in 0.5 M Na 2 SO 4 . Y. Xu et al [21] prepared ZnO thin films by hydrothermal synthesis at 95 • C for 4 h. WO 3 was then deposited on the prepared ZnO samples using magnetron sputtering at 1 Pa ambient air pressure and 65 W RF sputtering power. The ZnO-WO 3 composites obtained in their research achieved a photocurrent of 0.353 mA/cm 2 at 0.3 V vs. Ag/AgCl in a 0.5 M Na 2 SO 4 solution.…”