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[Display omitted] The practical photocatalytic application of cadmium sulfide (CdS) has been significantly constrained by fast carrier recombination and significant photocorrosion. Therefore, we developed a three-dimensional (3D) step-by-step (S-scheme) heterojunction using the coupling interface between purple tungsten oxide (W 18 O 49) nanowires and CdS nanospheres. The photocatalytic hydrogen evolution rate of optimized W 18 O 49 /CdS 3D S-scheme heterojunction can reach 9.7 mmol·h−1·g−1, 7.5 and 16.2 times greater than pure CdS (1.3 mmol·h−1·g−1) and 10 wt%-W 18 O 49 /CdS (mechanical mixing, 0.6 mmol·h−1·g−1), proving that the tight S-scheme heterojunction constructed by the hydrothermal method can efficiently enhance the carrier separation. Notably, the apparent quantum efficiency (AQE) of W 18 O 49 /CdS 3D S-scheme heterojunction approaches 7.5% and 3.5% at 370 nm and 456 nm, respectively, which is 7.5 and 8.8 times than pure CdS (1.0% and 0.4%). The produced W 18 O 49 /CdS catalyst also has relative stability of structure and hydrogen production. Additionally, the H 2 evolution rate of W 18 O 49 /CdS 3D S-scheme heterojunction is 1.2 times greater than 1 wt%-platinum (Pt)/CdS (8.2 mmol·h−1·g−1), which indicates that the W 18 O 49 can effectively replace the precious metal for boosting the hydrogen production rate. [ABSTRACT FROM AUTHOR]

[Display omitted] Semiconductor photocatalytic water splitting is a green way to convert solar energy into chemical energy, but the recombination of electron and hole pairs and the low utilization of sunlight restrict the development of photocatalytic technology. By comparing the morphologies and hydrogen production properties of different proportions of solid solutions (Cd x Zn 1- x S), one-dimensional (1D) Cd 0.9 Zn 0.1 S nanorods (NRs) with the best photocatalytic properties are obtained. In addition, 1D W 18 O 49 nanowires are assembled on the surface of 1D Cd 0.9 Zn 0.1 S NRs to construct a novel 1D/1D step-scheme (S-scheme) W 18 O 49 /Cd 0.9 Zn 0.1 S heterojunction photocatalyst. The W 18 O 49 /Cd 0.9 Zn 0.1 S heterojunction expands the optical absorption capacity of Cd 0.9 Zn 0.1 S NRs to provide more energy for the photoexcitation of electrons. The optimal hydrogen production rate of W 18 O 49 /Cd 0.9 Zn 0.1 S NRs with W 18 O 49 content of 9 wt% is as high as 66.3 mmol·h−1·g−1, which is 5.7 times and 1.6 times higher than that of Cd 0.9 Zn 0.1 S NRs and 1 wt% Pt/Cd 0.9 Zn 0.1 S NRs. The apparent quantum efficiency (AQE) of 9 wt% W 18 O 49 /Cd 0.9 Zn 0.1 S reaches 56.0 % and 25.9 % under light wavelength irradiation at 370 and 456 nm, respectively. After the 20 h cycle stability test, the activity of photocatalytic hydrogen evolution does not decrease, due that the severe photo-corrosion of Cd 0.9 Zn 0.1 S NRs is efficiently inhibited. This work not only provides a simple and controllable synthesis method for the preparation of heterojunction structure, but also opens up a new way to improve the hydrogen evolution activity and stability of sulfur compounds. [ABSTRACT FROM AUTHOR]