Photocatalytic activity enhanced by 1D TiO ₂ nanobelts and 2D BiVO ₄ nanosheets heterostructures

Abstract

Heterostructures that are formed by incorporating one-dimensional (1D) titanium dioxide (TiO 2) nanobelts into 2D bismuth vanadate (BiVO 4) nanosheets are fabricated via an electrostatic self-assembly process. The key features are investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller, zeta potential, ultraviolet-visible (vis) diffuse reflection spectra and photoluminescence spectra. As vis-light sensitiser and catalyst support, 2D BiVO 4 nanosheets can improve the vis-light photocatalytic activity of 1D TiO 2 nanobelts. Results show that 1D TiO 2 nanobelt-2D BiVO 4 nanosheet composites exhibit more efficient decomposition rate of rhodamine B compared with pure TiO 2 nanobelts. The photocatalytic activity of TiO 2-5% BiVO 4 composites is nearly 1.7 times higher than that of pure TiO 2 nanobelts. The enhanced photocatalytic performance is attributed to the bandgap match and the formation of heterostructures between TiO 2 nanobelts and BiVO 4 nanosheets. The heterostructures extend the light responsive range and promote efficient separation of photoinduced electron-hole pairs.

Bi 2 O 3 quantum dots decorated TiO 2 nanobelt heterojunctions with enhanced visible‐light photoactivity

“…Since pure TiO 2 can be only activated by ultraviolet (UV) light due to its large band gap of 3.2 eV, great efforts have been contributed to improving the photoactivity by extending spectral response into visible region through doping TiO 2 with metal or non-metal elements, but they usually exhibit poor activity and durability owing to their limited amount and easy leaching of dopants [4][5][6]. As a promising way, photosensitising TiO 2 with inorganic substrates has been recognised as an effective solution to extending the spectral response from the UV spectral range to the visible region [7][8][9][10]. Among various inorganic photosensitisers, Bi 2 O 3 is an important photosensitiser with a narrow band gap of 2.8 eV, which can extend the spectral response to the visible region and make the Bi 2 O 3 /TiO 2 as a visible-light photocatalyst through the photosensitising effect of Bi 2 O 3 [8][9][10].…”