@article{Deng2026, 
author = {Taojiang Deng and Chengyu Qin and Liming Sun and Li-Xia Liu and Wenwen Zhan and Guilin Zhuang and Jingyi Jia and Xiguang Han},
title = {Operando structural evolution of octahedral SnS2/SnO2 heterojunctions enabling efficient CO2-to-formate conversion over a broad potential window},
year = {2026},
journal = {Nano Research},
volume = {19},
number = {1},
pages = {94907848},
keywords = {heterojunction, CO2 reduction, structure evolution, reaction mechanisms, SnS2/SnO2},
url = {https://www.sciopen.com/article/10.26599/NR.2025.94907848},
doi = {10.26599/NR.2025.94907848},
abstract = {Heterostructure engineering has emerged as a promising strategy to enhance the electrochemical CO2 reduction reaction (CO2RR) by optimizing interfacial electron transfer. Herein, we report a novel octahedral SnS2/SnO2 heterojunction catalyst synthesized via an ion-exchange vulcanization method, which achieves exceptional activity and selectivity for CO2-to-formate conversion. Through in-situ Raman spectroscopy, ex-situ X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), we demonstrate that the octahedral SnS2/SnO2 heterojunction dynamically restructures into a sulfur-doped Sn/SnO2 (Sn(S)/SnO2) heterostructure under operating conditions. Density functional theory (DFT) calculations reveal that the Sn(S)/SnO2 interface facilitates electron transfer from SnO2 to metallic Sn(S), generating a built-in electric field that stabilizes Sn4+ in SnO2 and accelerates proton-coupled electron transfer to *OCHO intermediates. Consequently, the catalyst achieves a formate Faradaic efficiency exceeding 90% over a broad potential window (−0.6 to −1.0 V vs. reversible hydrogen electrode (RHE)) with a high partial current density of −280 mA·cm−2, surpassing most reported Sn-based catalysts. This work elucidates the structural dynamics and interfacial enhancement mechanisms of heterojunction catalysts, offering a rational design principle for advanced CO2RR electrocatalysts.}
}