In₂O₃/In₂S₃ Heterostructures Derived from In‐MOFs with Enhanced Visible Light Photocatalytic Performance for CO₂ Reduction

Abstract

A series of In2O3/In2S3 core‐shell heterostructures, derived from metal‐organic‐frameworks (MOFs), were successfully synthesized via a two‐step solvothermal route with different addition amount of sulfur‐bearing reagent (L‐cysteine, L‐Cys), which were used as photocatalysts for CO2 reduction with water vapor. The results indicated that 1.2‐In2O3/In2S3 with optimized L‐Cys addition amount had the highest production rate of CH4 (14.3 μmol gcat−1 h−1) and CO (2.59 μmol gcat−1 h−1). Pure In2O3 and 2.4‐In2O3/In2S3 with excess L‐Cys addition exhibited higher H2 production rate but lowest CO2 photoreduction activity. As the characterizations revealed, amorphous shell with abundant In2O3/In2S3 heterostructures greatly improved the separation efficiency of photo‐induced charge carriers and visible light harvesting ability, which promoted the photoreduction of CO2 consequently. However, over‐addition of sulfur‐bearing reagent destroyed the heterostructures of shell layer and turned them into thickened In2S3 crystal layer. This substitution not only reduced the amount of heterostructures, but also hindered the adsorption of CO2 on the reactive surface.

Frustrated Lewis Pairs on In(OH)3–x Facilitate Photocatalytic CO2 Reduction

“…The peak at 533.9 eV agreed with the surface oxygen chemisorbed. 37,39,40 The peak of In−O bonds was stronger than that of Zn−O bonds in ZIO, indicating that the content of In was more and the phase of In(OH) 3 was mainly formed, which was consistent with the results of XRD. Sulfurization induced a negative shift of the Zn 2p and In 3d peaks.…”

Metal‐Organic Frameworks‐Derived Nanocarbon Materials and Nanometal Oxides for Photocatalytic Applications

“…Similarly, In-MOF was annealed for 4 h in air and then treated by solvothermal method with sulfur-bearing reagent to obtain In 2 O 3 /In 2 S 3 coreshell heterojunction nanocomposites. [135] Specifically, the In-MOF presents a hexagonal rod-like structure. After calcination, the organic phase of the precursor is completely burned away, and In 2 O 3 particles appear along the surface of the hexagonal strips, forming a hollow structure.…”

“…Simultaneously, holes migrate from the valence band of ZnO to the valence band of NiO, oxidizing water molecules to generate oxygen and H + . Similarly, In‐MOF was annealed for 4 h in air and then treated by solvothermal method with sulfur‐bearing reagent to obtain In 2 O 3 /In 2 S 3 core‐shell heterojunction nanocomposites [135] . Specifically, the In‐MOF presents a hexagonal rod‐like structure.…”

Rational Design of Metal–Organic Framework‐Based Materials for Photocatalytic CO2 Reduction

“…Metal sulfide derivatives, as typical solar‐driven semiconductors, can be obtained by the liquid‐phase sulfidation treatment of the corresponding MOFs. [ 108 ] Via additional ion exchange steps in the synthetic process, the metal sulfide‐based heterostructure with the advantage in charge transfer could also be formed. Li's group converted Mn‐adsorbed MIL‐68 to a p–n heterostructure, that is, MnS/In 2 S 3 via a sulfidation process with thiourea.…”