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Oxygen-deficient TiO2-based composites have attracted widespread attention due to their promoted light-harvesting capacity and energy conversion efficiency, beneficial for water splitting. Despite being a facile, secure-safe and undefiled route for preparing blackened TiO2, the Al-reduction method has not been adopted for preparing TiO2/TiO2−x/CdS composite films. Herein, TiO2/TiO2−x/CdS composite nanorods were successfully fabricated by combining hydrothermal, Al-reduction and chemical bath deposition (CBD) techniques. Enhanced visible-light absorption and photoelectrochemical performances have been achieved using TiO2/TiO2−x/CdS heterojunction nanorods. The photocurrent density of TiO2/TiO2−x/CdS was obtained to be 7.75 mA cm−2 at 0 V vs. Ag/AgCl under AM 1.5 G illumination, which was 77.5-fold and 12.1-fold higher than those of bare TiO2 and CdS, respectively. This work may offer new insights for realizing TiO2-based composites with improved solar absorption for photoelectrochemical applications. [ABSTRACT FROM AUTHOR]

Layered bismuth oxychalcogenides have been demonstrated as potential candidates for high-speed and low-power electronics due to their outstanding environmental stability and high carrier mobility, but the photoelectric performance of bulk species is still far from satisfactory. Herein, a novel Bi9O7.5S6/CdS composite film with a type-II heterojunction has been successfully prepared by combining chemical bath deposition (CBD) and spin-coating technologies. The structure, morphology, optical and photoelectric properties of the samples were investigated systematically. The photoelectric current of the Bi9O7.5S6/CdS composite film was obtained as 32.49 μA cm−2 at 1 V, which is about 13.9-fold and 3.3-fold higher than those of bare Bi9O7.5S6 and CdS. An enhanced photoelectric response and photostability were achieved in the Bi9O7.5S6/CdS composite film, and can be appropriately attributed to the improved separation and transfer of photogenerated carriers driven by the type-II heterojunction. This work offers a promising route to develop high-performance visible-light photoelectric devices with type-II heterojunctions. [ABSTRACT FROM AUTHOR]

Layered bismuth oxychalcogenides have recently emerged as promising photoelectric materials due to their visible-light bandgaps, effective charge separation, high carrier mobility, and long carrier lifetime. In order to verify the potential application of Bi 9 O 7.5 S 6 for water splitting, Bi 9 O 7.5 S 6 /CdS composite film was prepared by combining the knife-coating and chemical bath deposition (CBD) methods. The structure, morphology and band positions were completely checked and revealed a type Ⅱ heterojunction structure in Bi 9 O 7.5 S 6 /CdS composite film. The thickness-dependent optical, impedance and photoelectrochemical properties have been also studied. Under the irradiation of AM 1.5 G simulated sunlight, a stable photocurrent density of ∼ 259.73 μA/cm2 has been obtained for the Bi 9 O 7.5 S 6 /CdS photoanode at 0 V vs. Ag/AgCl, which is about 5-fold and 40-fold higher than that of bare CdS and Bi 9 O 7.5 S 6 photoanodes due to the formation of the type Ⅱ heterojunction between Bi 9 O 7.5 S 6 and CdS. This work demonstrates the promising prospects of layered bismuth oxychalcogenide as cost effective, highly stable and efficient photocatalysts for water splitting. [Display omitted] • Bi 9 O 7.5 S 6 /CdS/ITO composite film was fabricated as a photoelectrode of PEC. • A type Ⅱ heterojunction has been revealed by UV–Vis and UPS spectra measurements. • The separation and migration of photogenerated carriers have been accelerated. • Giant enhanced photocatalytic activity has been achieved in Bi 9 O 7.5 S 6 /CdS/ITO composite film. [ABSTRACT FROM AUTHOR]