Architecting smart “umbrella” Bi₂S₃/rGO-modified TiO₂ nanorod array structures at the nanoscale for efficient photoelectrocatalysis under visible light

Abstract

Umbrella hybrid (Bi2S3/rGO)5/TiO2 nanorod arrays with high light absorption and stepwise band-edge structure accomplish high conversion efficiency under visible light.

TiO2 photoanodes with exposed {0 1 0} facets grown by aerosol-assisted chemical vapor deposition of a titanium oxo/alkoxy cluster

“…The small resistance values suggest a better separation efficiency and faster transfer rate for photogenerated electrons and holes at the electrode/electrolyte interface. 78,79 This good charge-transfer properties agree well with J-V curves, where high photocurrent performances are obtained for TiO 2 -Rose-800.…”

“…10a shows Nyquist plots along with the equivalent circuit used, which include a R 1 /CPE 1 pair which describes the semiconductor resistance and capacitance at the depletion layer and a second R 2 /CPE 2 pair for the resistance and capacitance of the semiconductor at the interface between the electrolyte and photoanode (Helmholtz layer). 78 Based on the obtained tted results, TiO 2 -Rose-800 photoanode has resistance values of 35.6 U for R 1 and 821 U for R 2 . The small resistance values suggest a better separation efficiency and faster transfer rate for photogenerated electrons and holes at the electrode/electrolyte interface.…”

Cu2S nanoparticles modified 3D flowerlike Bi2WO6: Enhanced photoelectric performance and photocatalytic degradation

“…R 2 //CPE 1 components represent the resistance of semiconductor depletion layer (space charge layer) and the chemical capacitance. R 3 //CPE 2 represent the charge transfer resistance in the Helmholtz layer (double layer) and the recharged Helmholtz layer [8] . The semicircular Nyquist plots as shown in Fig.2B indicate that the electron transfer on the electrode interface plays a dominant role in the electrode process [9] .…”

Graphenes as additives in photoelectrocatalysis

“…Besides seeking for other transition metal to replace Cd 2+ , the combination of metal sulfides having narrow band gap with wide band gap metal oxides, the former acting as light harvesters for the wide bandgap oxide, is known to increase the stability of the photocatalyst, while still enjoying high photocatalytic performance. In one of the examples combining metal oxides, sulfides and graphene, a photoelectrode constituted by TiO 2 nanorods on transparent FTO electrode was modified by consecutive deposition cycles in which Bi 2 S 3 and rGO were deposited 104 . The resulting composite is schematically represented in Figure 14, where the proposed role of each of the components has been indicated.…”

“…Reproduced from ref. 104 . The purpose of the multilayer assembled was to extend the photoresponse of the CdS by including a narrow band gap metal sulfide (Ag 2 S) and increase charge separation, electron mobility and conductivity by the presence of rGO.…”