MOFs-derived plum-blossom-like junction In/In2O3@C as an efficient nitrogen fixation photocatalyst: Insight into the active site of the In3+around oxygen vacancy

Nitrogen activation with low-cost, visible-light-driven photocatalysts continues to be a major challenge. Since the discovery of biological nitrogen fixation, multi-component systems have achieved higher effi-ciency due to the synergistic effects, thus one of the challenges has been distinguishing the active sites in multi-component catalysts. In this study, we report the photocatalysts of In/In2O3@C with plume -blossom-like junction structure obtained by one-step roasting of MIL-68-In. The branch is carbon for supporting and protecting the structure, and the blossom is In/In2O3 for the activation and reduction of N2, which form an efficient photocatalyst for nitrogen fixation reaction with the performance of 51.83 lmol h-1 g . Experimental studies and DFT calculations revealed the active site of the catalyst for nitrogen fixation reaction is the In3+ around the oxygen vacancy in In2O3. More importantly, the ele-mental In forms the Schottky barrier with In2O3 in the catalyst, which can generate a built-in electric field to form charge transfer channels during the photocatalytic activity, not only broadens the light absorp-tion range of the material, but also exhibits excellent metal conductivity.(c) 2023 Elsevier Inc. All rights reserved.

Automated summary

This study presents a one-step roasting process to prepare In/In2O3@C photocatalysts with a plume-blossom-like junction structure, where carbon acts as a supporting and protective structure, and In/In2O3 serves for the activation and reduction of N2. The photocatalyst exhibits efficient nitrogen fixation reaction with a performance of 51.83 lmol h-1 g, and the active site for nitrogen fixation reaction is identified as the In3+ around the oxygen vacancy in In2O3. Moreover, the elemental In forms a Schottky barrier with In2O3, generating a built-in electric field for charge transfer channels during photocatalytic activity, which enhances light absorption and exhibits excellent metal conductivity.