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Photothermal-assisted photocatalytic H 2 evolution has attracted increasing attention in solar energy-hydrogen energy conversion. Herein, a novel Mn 0.2 Cd 0.8 S/NiSe 2 (MCS/NiSe 2) nanocomposite heterojunction with photothermal and co-catalyst dual effects was constructed to boost visible-near-infrared (Vis-NIR) light-driven H 2 evolution activity. MCS/NiSe 2 nanocomposite could obtain increased light absorption intensity, affluent active reaction sites and enhanced charge separation efficiency because of the decoration of NiSe 2 co-catalyst. Meanwhile, the photothermal effect of NiSe 2 could raise reaction system temperature, thus further accelerating carriers transfer and surface reaction rate. Consequently, MCS/NiSe 2 nanocomposite could obtain the highest H 2 evolution rate of 22.5 mmol g−1 h−1 under Vis-NIR light irradiation, reaching 3.2 times of MCS. This work provides a novel idea for the rational design of efficient photocatalysts by making full utilization of the synergetic effects of co-catalyst modification and photothermal effect without external heating source. [Display omitted] ● Contact interface between NiSe 2 and Mn 0.2 Cd 0.8 S promoted charge transfer. ● NiSe 2 nanoparticles provided abundant active sites. ● Photothermal effect without external heat energy increased system temperature. ● High system temperature facilitated charge separation and H 2 evolution reaction. ● Enhanced activity was attributed to the co-catalyst effect and photothermal effect. [ABSTRACT FROM AUTHOR]

The construction of p–n heterojunction is an efficient strategy to restrain photogenerated charge carriers recombination and enhance the photocatalytic efficiency toward H 2 evolution from water splitting. Herein a novel p–n heterojunction Mn 0.25 Cd 0.75 S/Co 3 O 4 was synthesized via facile hydrothermal method. Photocatalytic H 2 evolution of as-synthesized Mn 0.25 Cd 0.75 S/Co 3 O 4 composites in the absence of noble metal co-catalysts under visible light irradiation ( λ ≥ 400 nm) was investigated. The results demonstrated that photocatalytic H 2 evolution of Mn 0.25 Cd 0.75 S was significantly enhanced by loading Co 3 O 4 nanoparticles. It was confirmed that 0.48 wt% of Co 3 O 4 loading content achieved the highest H 2 evolution rate of 25.71 mmol/g/h, which was about 5.35 times higher than that of pure Mn 0.25 Cd 0.75 S. The remarkably improved photocatalytic activity could be attributed to the formation of the p–n junction at the interface between Mn 0.25 Cd 0.75 S and Co 3 O 4 , effectively promoting interfacial charge transfer and separation. This work revealed that the p–n heterojunction Mn 0.25 Cd 0.75 S/Co 3 O 4 may be a promising candidate for efficient energy conversion. [ABSTRACT FROM AUTHOR]

Development of efficient, economical and stable photocatalysts that can maximize the utilization of ultraviolet (UV), visible (Vis) and near-infrared (NIR) light for photocatalytic H 2 evolution remains a challenge. Herein, polyhedral Mn 0.2 Cd 0.8 S (MCS) modified with amorphous NiB nanoparticles was rationally constructed by in-situ synthesis method. Compared to MCS, the optimized MCS/NiB composite exhibited much superior activity with the H 2 evolution rate of 21.6, 29.1, 35.4 and 45.6 mmol g–1 h–1 under Vis (420–780 nm), Vis-NIR (420–1100 nm), UV-Vis (350–780 nm) and UV-Vis-NIR (300–1100 nm) light irradiation, respectively. The enhanced activity was attributed firstly to high charge carrier separation efficiency and adequate active reaction sites due to the modification of NiB co-catalyst and secondly to the enhanced photothermal effect owing to the introduction of full spectrum-responsive NiB. This work provides a new perspective for designing photothermal effect-enhanced photocatalytic system. [Display omitted] • Mn 0.2 Cd 0.8 S/NiB composite was in-situ constructed. • Interfacial contact between two component promoted charge transfer. • NiB co-catalysts provided abundant active reaction sites. • Photothermal effect without external heat energy raised system temperature. • Co-catalyst modification and photothermal effect were responsible for the enhanced activity. [ABSTRACT FROM AUTHOR]