Effect of TiO2 nanoparticle load on photoelectric properties of TiO2/VGs heterojunction

Preparation of Titanium dioxides loaded vertical graphene nanosheets (TiO 2 /VGs) composite films with heterojunctions by a multi -plasma combination method. Highly vertically oriented VGs were prepared by helicon wave plasma chemical vapor deposition (HWP-CVD), and TiO 2 nanoparticles were deposited on VGs templates by ultra -high vacuum magnetron sputtering (UH -MS). By controlling the sputtering time of TiO 2 nanoparticles to modulate the nanoparticle loading content. The morphology, structure, and photocatalytic performance of heterojunction TiO 2 /VGs composite films were investigated. The characterization results of morphology and structure show that the structure of VGs nanosheets is not altered by the increase of the deposited particle content, indicating that VGs have excellent mechanical properties as a template for TiO 2 loading. As the deposition time of the TiO 2 nanoparticles increases, the loading type progresses from epitaxial growth at the beginning to conformal deposition and eventually to gap-filling growth. Photoelectric performance tests showed that the heterojunctions were formed at the interface between TiO 2 and VGs. The photovoltage test results show that the photogenerated carriers are effectively separated at the interface, and the nanosheets can promote the migration of separated electrons to the external circuit. The variation in photocurrent density shows a positive correlation with the number of TiO 2 attachment sites and loading content on the surface of the VGs nanosheets.