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The interfacial regulation strategy between semiconductors can effectively promote the separation efficiency of photogenerated carriers and enhance photocatalytic activity under the synergistic effect. Herein, AgInS 2 QDs-MoS 2 /GO (AIS-MS/GO) composites were prepared by interfacial coupling of AgInS 2 QDs (AIS), hierarchical MoS 2 and ultrathin GO. Ultrathin GO successfully solved the agglomeration problem of AIS and hierarchical MoS 2. Moreover, the photogenerated carriers were effectively separated and transferred under the synergistic effect of the AIS-MS heterojunction and ultrathin GO, thus promoting tetracycline (TC) degradation and CO 2 reduction performance. The degradation rate of tetracycline (TC) reached 96.5 %, and the yields of CO and CH 4 in the CO 2 reduction products reached 52.6 and 28.5 μmol g–1, respectively, when using the optimized photocatalyst. In-situ FTIR analysis indicated that TC is gradually degraded by small molecules on the composite surface, and has excellent dissociation ability of water molecules during the CO 2 reduction process. This work provides a new vision for the rational design of heterojunction-based photocatalysts using the interfacial regulation strategy for enhancing interfacial charge separation and photocatalytic performance. [Display omitted] • AIS-MS/GO composites were prepared via the interfacial regulation strategy. • The photogenerated carriers were effectively separated and transferred under synergistic and interfacial effects. • The aggregation problem of AIS and hierarchical MoS 2 was effectively solved. • AIS-MS/GO composites achieve a 96.5 % TC degradation rate and 35.1 % selectivity for CH 4. [ABSTRACT FROM AUTHOR]

Energy band location and charge separation mechanism of SnS 2 /Au/g-C 3 N 4 system during photoreduction under sunlight irradiation. • The catalyst is prepared by facile thermal treatment and chemical deposition method. • The SnS 2 /Au/g-C 3 N 4 composites show a superior optical adsorption under UV–vis light. • The Au nanoparticle and the Z-type scheme jointly improve the separation of carrier. • The SnS 2 /3ml-Au/g-C 3 N 4 displays the best photoreduction activity and durability. The use of semiconductor photocatalytic reduction technology has higher efficiency and lower energy consumption for CO 2 reduction, but its existence of some mismatched energy band positions and relatively slow charge-hole separation greatly limits its practical application. In this paper, a SnS 2 /Au/g-C 3 N 4 embedded structure model with carbon and nitrogen hybridization is proposed to gain an in-depth understanding of the role of hybridization and precious metal modification in photocatalysis. Carriers were investigated from the perspective of kinetics through photocurrent, LSV curve, and FL spectroscopy. After modification of Au nanoparticles, the photo-excited electrons showed a slower decay process, indicating that the separation of carriers was enhanced, which was further confirmed by impedance and PL spectroscopy. SEM, AFM and TEM analysis confirmed that the 2D face-to-face SnS 2 /Au/g-C 3 N 4 embedded structure was successfully prepared and the Au nanoparticles were evenly distributed. Au nanoparticles not only act as a bridge for electron transport in 2D semiconductor materials to accelerate electron transport, but generate more excited electrons by themselves under the radiation of sunlight, which effectively improves the separation efficiency of electron-hole pairs and enhances the photocatalyst activity. DFT calculations show that the Z-type mechanism and the intercalated energy level of the SnS 2 /Au/g-C 3 N 4 embedded structure expand the light absorption and improve the carrier separation efficiency. As expected, the photocatalyst activity with CO and CH 4 the evolution rate of up 93.81 µmol·g−1·h−1 and 74.98 µmol·g−1·h−1 under visible light irradiation, respectively, while the photocatalytic activity is negligible loss after 30 h photoreduction. This work reveals the role of embedded structure and precious metal modification in the separation and transmission of electron-hole, opening up new perspective for achieving high-efficiency solar CO 2 reduction performance. [ABSTRACT FROM AUTHOR]