NiSe2 nanoparticles modified ZnIn2S4 microspheres for boosting photocatalytic hydrogen evolution under visible light irradiation.

Under visible light illumination, the synthesized ZnIn 2 S 4 /NiSe 2 composites achieved up to a hydrogen evolution rate of 3060 µmol/gh−1. The presence of co-catalyst NiSe 2 provided a faster electron transfer channel and greatly suppressed the recombination of photo-generated charges, thereby enhancing the photocatalytic activity. [Display omitted] • A self-assembled microsphere ZnIn 2 S 4 modified by NiSe 2 nanoparticles was successfully prepared by a hot-injection method and successive solvothermal method. • Benefiting from the close contact interface and synergistic effect between ZnIn 2 S 4 and NiSe 2 , the synthesized ZnIn 2 S 4 /NiSe 2 composites achieved up to a photocatalytic hydrogen evolution rate of 3060 µmol/gh−1 without any noble metal loading. • The successful formation of the composite was conducive to the photo-generated electron flow from ZnIn 2 S 4 to NiSe 2 , which improved the charge migration efficiency and retarded the photogenerated carrier recombination. • The ZnIn 2 S 4 /NiSe 2 composite exhibited elevated absorption, redshift absorption edge, and decreased band gap, which were beneficial for light utilization. • The ZnIn 2 S 4 /NiSe 2 composite also exhibited good stability with no obvious decay within 20 h. A well-designed composite based on semiconductor materials can effectively reduce the recombination of photo-generated carriers in photocatalysts by establishing efficient charge transfer channels, which enhances the activity of photocatalytic hydrogen evolution for water splitting. Herein, a ZnIn 2 S 4 /NiSe 2 composite with NiSe 2 nanoparticles tightly anchored on the nanosheets-assembled microspheres ZnIn 2 S 4 was elaborated and successfully synthesized by a hot-injection method followed by a successive solvothermal method. The synergistic effects and close contact interface between ZnIn 2 S 4 and NiSe 2 facilitated charge migration. Under visible light irradiation, the optimal ratio of ZnIn 2 S 4 /NiSe 2 composite achieved an outstanding hydrogen evolution rate of 3060 µmol g−1 h−1 (nearly 12.6 times of unmodified ZnIn 2 S 4) and exhibited superior stability (no apparent decrease within 20 h) in the presence of a sacrificial agent (triethanolamine). Additionally, various characterizations revealed that the recombination of photo-generated carriers was effectively suppressed, visible-light absorption was significantly enhanced, and interface charge transfer was accelerated, thus endowing the ZnIn 2 S 4 /NiSe 2 composite with superior photocatalytic activity. This research provides illuminating insights into using the non-noble metal-based catalyst NiSe 2 as an effective co-catalyst, significantly improving photocatalytic performance and holding great potential in alleviating energy shortages and environmental pollution problems. [ABSTRACT FROM AUTHOR]