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Exploration of low-cost and earth-abundant photocatalysts for efficient photocatalytic H2 evolution from water is an attractive solution to the global energy and environmental problems. Although MoS2 has been proved as an efficient co-catalyst for the H2 evolution reaction (HER), controllably and accurately constructing MoS2-hybridized photocatalysts at where the electrons extracted still remains a challenge. Here, a facile two-step approach of photoetching-photodeposition has been developed to prepare MoSx/etched-CdS (Mo-Cd(e)-S) with heterostructure accurately constructed on the CdS surface defects. This structure can significantly accelerate photo-induced charge separation and transportation owing to the place of heterostructure construction matching well with that of electrons extracted, numerous active sites introduced, and shorter charge transfer path from bulk to surface. Therefore the charge recombination is significantly retarded. As a result, the Mo-Cd(e)-S exhibits outstanding photocatalytic performance with a state-of-the-art H2 generation rate of 22.5 mmol g−1 h−1 under visible light irradiation (λ ≥ 420 nm) which is 70 times higher than that of pristine CdS. This work opens a new avenue for the low-cost but high efficient photocatalysts development.

International audience; Unsatisfactory crystal quality and deep-level defects are detrimental for Cu(In,Ga)(S,Se)2 (CIGSSe) solar cells. In this work, an in-suit K doping strategy is implemented by introducing KF into the CIGSSe precursor solution to promote crystallization and passivate the deep defects. The effects of K on the solution-processed CIGSSe devices are systematic investigated. It has been discovered that K incorporation results in better crystallization, modified CIGSSe surface and fewer detrimental defects. Benefit from the reduction of the band-tailing effects, suppressed defects density and passivated interface recombination, the solution-processed CIGSSe solar cell achieve systematic improvement in open-circuit voltage and fill factor, enabling a champion efficiency of 16.02%, which is the highest value for alkali metal doped CIGSSe solar cells fabricated by solution-processed method. The effective in-suit K doping tactic opens an avenue for developing highly efficient solution-processed CIGSSe solar cells.

Photocatalytic H2 evolution from water splitting offers an attractive scientific and technological method to address the energy and environmental crisis. In this study, noble-metal-free Zn0.5Cd0.5S@MoS2 core@shell nanoheterostructures were elaborately designed and successfully synthesized. The visible-light-driven photocatalytic performance investigation shows that the Zn0.5Cd0.5S@MoS2 exhibits a state-of-the-art H2 evolution rate of 40.2 mmol g−1 h−1 far exceeding that of pristine Zn0.5Cd0.5S by more than 57 times. Moreover, thanks to the protection of MoS2 shells, the Zn0.5Cd0.5S@MoS2 can retain long-term stability in four-cycles of 24 h reactions. Furthermore, a tentative mechanism on H2 generation was systematically investigated and proposed, which contributes to understand the enhanced photocatalytic activity of the Zn0.5Cd0.5S@MoS2 heterostructures and may inspire the synthesis of other desirable catalytic systems.