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The novel magnetically recyclable direct Z-scheme Cd x Zn 1-x S-FG nanocomposites were synthesized by a simple hydrothermal method, which displayed the excellent photocatalytic hydrogen evolution and photocatalytic degradation activity under visible light irradiation. [Display omitted] • The Cd x Zn 1-x S-FG multifunctional photocatalysts were successfully synthesized by a simple hydrothermal method. • The photocatalytic hydrogen evolution and photocatalytic degradation properties of the samples were investigated under visible light irradiations. • The direct Z-scheme transfer of electron-hole pairs was confirmed in Cd x Zn 1-x S-FG nanocomposites. • An easy magnetically separable and recoverable process was achieved. In this paper, we reported a simple hydrothermal strategy to prepare the direct Z-scheme Cd x Zn 1-x S nanorods-Fe 2 O 3 quantum dots heterojunction/reduced graphene oxide (Cd x Zn 1-x S-FG) nanocomposites as the multifunctional photocatalysts for photocatalytic degradation of organic dyes and photocatalytic hydrogen evolution. By adjusting the molar mass ratio of Cd2+ and Zn2+ ions from 9:1 to 1:9, the bandgap of the Cd x Zn 1-x S-FG nanocomposites can be turned from 2.23 to 3.49 eV. The Cd 0.3 Zn 0.7 S-FG nanocomposites exhibited the highest H 2 evolution rate of 26.8 mmol h−1 g−1 and the highest degradation efficiency of 97.32% towards MB in 120 min under the visible light irradiation. The excellent photocatalytic activity can be attributed to the high-efficiency transportation and separation of the photogenerated electron-hole pairs, more catalytic active sites and large specific surface area. The mechanism of the photocatalytic hydrogen evolution and photocatalytic degradation had been investigated by ultraviolet photoelectron spectroscopy, scavenging experiment, and UV–Vis absorption spectra. Considering the unique structure, morphology, and excellent photocatalytic performances of the Cd x Zn 1-x S-FG nanocomposites, it will become a burning star in the field of photocatalysis. [ABSTRACT FROM AUTHOR]

The novel magnetically recyclable direct Z-scheme GZxFy nanocomposites were synthesized by a simple hydrothermal method, which displayed the excellent photocatalytic activity under UV and visible light irradiation. • The GZxFy nanocomposites photocatalysts were successfully synthesized by a simple hydrothermal method. • The photocatalytic properties of the samples were investigated under UV and visible light irradiations. • The direct Z-scheme transfer of electron-hole pairs was confirmed in GZxFy nanocomposites. • An easy magnetically separable and recoverable process was achieved. A novel direct Z-scheme ZnS quantum dot (QD)-Fe 2 O 3 QD heterojunction/reduced graphene oxide (rGO) (GZxFy) nanocomposite was successfully synthesized by a simple hydrothermal method. The surface of ZnS and Fe 2 O 3 QDs was modified by COOH and OH groups, respectively. ZnS QDs can be covalently bonded with Fe 2 O 3 QDs by the dehydration reaction to form the ZnS QDs-Fe 2 O 3 QDs heterojunctions. The GZxFy nanocomposites displayed the highest photodegradation efficiency of 96.45% (40 min, UV light) and 90.17% (480 min, visible light) for methylene blue when the mass ratio of ZnS QDs to Fe 2 O 3 QDs was 1:3. The excellent photocatalytic activity could be attributed to the enhanced light-harvesting ability, high large specific surface area, efficient interfacial charge-carrier separation and transfer as well as the low charge transfer resistance. Ultraviolet photoelectron spectroscopy and radical trapping experiments were used to confirm the Z-scheme mechanism formed between ZnS QDs and Fe 2 O 3 QDs, and verify the electron transfer direction for UV or visible light-driven photocatalytic reactions. GZ1F3 nanocomposites showed the excellent superparamagnetic behavior, which enabled its rapid magnetic recycle from the solution within 95 s in a magnetic field. [ABSTRACT FROM AUTHOR]