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Due to the exceptional potential to retard the charge recombination, semiconductor-based heterojunctions as photocatalysts have attracted extensive attention. Herein, nickel(II) 5,10,15,20-tetraphenyl-21H,23H-porphyrin (NiTPP) and ZnIn 2 S 4 (ZIS) floriated microspheres are used to construct a novel inorganic-organic heterojunction (NiTPP/ZIS). Compared with the NiTPP and ZIS, the resultant NiTPP/ZIS exhibits enhanced optical absorption, charge separation and photoelectrochemical behavior. Further investigations demonstrate that a type II heterojunction mechanism proceeds in the NiTPP/ZIS heterojunction to boost the charge separation via the Ni-S highway formed between the NiTPP and ZIS components. No need of additional cocatalyst, the NiTPP/ZIS heterojunction with an optimal mass ratio delivers a superior apparent quantum yield of 64.0% at 400 nm and a remarkable H 2 evolution activity of 2305 μmol h−1 under visible light (λ ≥ 400 nm) irradiation, 10 and 256 times higher than that of the ZIS and NiTPP alone, respectively. This work presents a new concept for constructing inorganic-organic heterojunctions for high-performance artificial photosynthesis systems. [Display omitted] • A novel NiTPP/ZIS inorganic-organic hybrid material is synthesized via reflux method. • Ni-S channel between the NiTPP and ZIS components acts as highway for charge transfer. • A type II heterojunction mechanism is promoted via the Ni-S charge transfer channel. • Efficient charge separation causes superior apparent quantum yield of 64.0% at 400 nm. • Achieved 10 times higher H 2 yield than ZIS irradiated by visible light without cocatalyst. [ABSTRACT FROM AUTHOR]

Developing highly efficient heterojunction photodetector, especially ternary heterojunctions of vertical structure, is a promising strategy to enhance the migration of photo-generated electron for exploit potentialities of optoelectronic devices. In this study, we successfully deposited two-dimensional layered SnSe 2 NSs and SnS 2 NSs vertically on TiO 2 NTs arrays using chemical vapor deposition (CVD), constructing a novel ternary SnS 2 /SnSe 2 /H–TiO 2 heterojunction. The morphology, structure, and composition of the samples were analyzed, and highly sensitive ultraviolet/visible light photodetectors were fabricated. Photocurrent measurements demonstrated that the prepared SnS 2 /SnSe 2 /H–TiO 2 ternary heterojunction exhibited superior light detection capability at different wavelengths (370 nm, 450 nm, 520 nm) compared to the pristine H–TiO 2 and its binary heterojunctions (SnS 2 /H–TiO 2 , SnSe 2 /H–TiO 2). Under a bias voltage of 1 V and 370 nm illumination, it achieved a high photocurrent of 7.45 mA cm−2, a switch ratio of 7.924, as well as high responsivity (9.39 A/W), high EQE (3.15 × 103 %), and large detectivity (9.53 × 1010 Jones). The excellent performance of the SnS 2 /SnSe 2 /H–TiO 2 ternary heterojunction reveals its enormous potential in the development of wide-band, high-performance photodetectors. [Display omitted] • A ternary SnS 2 /SnSe 2 /H–TiO 2 heterojunction with vertical structure was prepared by in-situ growth of high-quality SnSe 2 and SnS 2 nanosheet arrays on the surface of TiO 2 nanotubes using a two-step CVD method. • The SnS 2 /SnSe 2 /H–TiO 2 heterostructure is directly fabricated into a photodetector. • The photodetector presents outstanding photoresponse activity at different wavelengths with a high photocurrent of 7.45 mA cm−2, high responsivity (9.39 A/W), high EQE (3.15 × 103 %), and a large detectivity (9.53 × 1010 Jones) under 370 nm illumination. • Compared to binary heterostructures (SnS 2 /H–TiO 2 , SnSe 2 /H–TiO 2), the ternary SnS 2 /SnSe 2 /H–TiO 2 detector exhibits a wider photoresponse range, higher optoelectronic performance, and better stability, demonstrating outstanding overall performance. [ABSTRACT FROM AUTHOR]