MOF-Derived Hollow Tubular In 2 O 3 /M II In 2 S 4 (M II : Ca, Mn, and Zn) Heterostructures: Synergetic Charge-Transfer Mechanism and Excellent Photocatalytic Performance to Boost Activation of Small Atmospheric Molecules

The rational design of hierarchical In 2 O 3 /M II In 2 S 4 (M II: Ca, Mn, and Zn) hollow tubular (HT) heterostructures was successfully performed by the preferential growth of ternary metal sulfide (M II In 2 S 4 ) two-dimensional (2D) nanosheets on MIL-68(In) metal–organic framework (MOF) derived hollow tubular In 2 O 3 using a facile low-temperature reflux reaction. The efficiency of HT-In 2 O 3 /M II In 2 S 4 binary heterojunctions was studied for the photocatalytic activation of small atmospheric molecules. The ultrafast interfacial charge migration, better photoexcited charge separation, and significantly improved photocatalytic H 2, NH 3, and H 2 O 2 production could be attributed to the narrow band gap energy of the M II In 2 S 4 and S-scheme electron migration mechanism between In 2 O 3 and M II In 2 S 4 components in the heterostructures. Thanks to its structural and compositional advantages, the optimal HT-In 2 O 3 /M II In 2 S 4 (1:1) heterostructure photocatalysts exhibited outstanding photocatalytic hydrogen evolution reaction and nitrogen and oxygen reduction reaction activity under visible-light illumination. Among the HT-In 2 O 3 /M II In 2 S 4 (1:1) hetrostructures, the HT-In 2 O 3 /ZnIn 2 S 4 (1:1) photocatalyst displayed the highest H 2, NH 3, and H 2 O 2 generation (5331, 870, and 5716 μmol g –1 h –1 ) with conversion efficiency of 34%, 6.5%, and 0.291%, respectively. This study offers a comprehensive analysis on how the coupling of three different d 0, d 5, and d 10 ternary metal chalcogenides M II In 2 S 4 with HT-In 2 O 3 affects the photocatalytic H 2, NH 3, and H 2 O 2 production.