Oriented synthesis of transition metal sulfides (TMSs) with controlled compositions and crystal structures has long been promising for electronic devices and energy applications. Liquid-phase cation exchange (LCE) is a wellstudied route by varying the compositions. However, achieving crystal structure selectivity is still a great challenge. Here, we demonstrate gas-phase cation exchange (GCE), which can induce a specific topological transformation (TT), for the synthesis of versatile TMSs with identified cubic or hexagonal crystal structures. The parallel six-sided subunit (PSS), a new descriptor, is defined to describe the substitution of cations and the transition of the anion sublattice. Under this principle, the band gap of targeted TMSs can be tailored. Using the photocatalytic hydrogen evolution as an example, the optimal hydrogen evolution rate of a zinc-cadmium sulfide (ZCS4) is determined to be 11.59 mmol h À 1 g À 1 , showing a 36.2-fold improvement over CdS.

Oriented synthesis of transition metal sulfides (TMSs) with controlled compositions and crystal structures has long been promising for electronic devices and energy applications. Liquid‐phase cation exchange (LCE) is a well‐studied route by varying the compositions. However, achieving crystal structure selectivity is still a great challenge. Here, we demonstrate gas‐phase cation exchange (GCE), which can induce a specific topological transformation (TT), for the synthesis of versatile TMSs with identified cubic or hexagonal crystal structures. The parallel six‐sided subunit (PSS), a new descriptor, is defined to describe the substitution of cations and the transition of the anion sublattice. Under this principle, the band gap of targeted TMSs can be tailored. Using the photocatalytic hydrogen evolution as an example, the optimal hydrogen evolution rate of a zinc‐cadmium sulfide (ZCS4) is determined to be 11.59 mmol h−1 g−1, showing a 36.2‐fold improvement over CdS.

Solid solution-oxide heterostructures combine the advantages of solid solution and heterojunction materials to improve electronic structure and optical properties by metal doping, and enhance charge separation and transfer in semiconductor photocatalysts by creating a built-in electric field. Nevertheless, the effective design and synthesis of these materials remains a significant challenge. Here, we develop a generally applicable strategy that leverages the transformable properties of metal-organic frameworks (MOFs) to prepare solid solution-oxide heterojunctions with controllable structural and chemical compositions. The process consists of three main steps. First, MOFs with different topological structures and metal centers are transformed, accompanied by pre-nucleation of a metal oxide. Second, solid solution is prepared through calcination of the transformed MOFs. Finally, a heterojunction is formed by combining solid solution with another metal oxide group through endogenous overflow. DFT calculations and study on carrier dynamics show that the structure of the material effectively prevents electrons from returning to the bulk phase, exhibiting superior photocatalytic reduction performance of CO 2 . This study is expected to promote the controllable synthesis and research of MOF-derived heterojunctions.

The rational design, synthesis and massive production of one-dimensional (1D) spinel composite oxides with multiple-shell nanostructures are critical to the realization of highly efficient energy conversion and storage. However, owing...

Solid solution‐oxide heterostructures combine the advantages of solid solution and heterojunction materials to improve electronic structure and optical properties by metal doping, and enhance charge separation and transfer in semiconductor photocatalysts by creating a built‐in electric field. Nevertheless, the effective design and synthesis of these materials remains a significant challenge. Here, we develop a generally applicable strategy that leverages the transformable properties of metal–organic frameworks (MOFs) to prepare solid solution‐oxide heterojunctions with controllable structural and chemical compositions. The process consists of three main steps. First, MOFs with different topological structures and metal centers are transformed, accompanied by pre‐nucleation of a metal oxide. Second, solid solution is prepared through calcination of the transformed MOFs. Finally, a heterojunction is formed by combining solid solution with another metal oxide group through endogenous overflow. DFT calculations and study on carrier dynamics show that the structure of the material effectively prevents electrons from returning to the bulk phase, exhibiting superior photocatalytic reduction performance of CO2. This study is expected to promote the controllable synthesis and research of MOF‐derived heterojunctions.