Abstract
Electrochemical O2 activation offers a green approach for efficient synthesis of singlet oxygen (1O2). However, it is commonly determined by adsorption-dependent O2 activation and transformation and can suffer from the sluggish desorption of surface-bound *OOH. Here we report an adsorption-independent O2 activation pathway for 1O2 electrosynthesis via an O2 mono-hydrogenation process on compressive-strained rutile TiO2 (CSR-TiO2). This CSR-TiO2 achieved an 1O2 generation rate of 148.26 μmol l−1 min−1 with near 100% Faradaic efficiency, outperforming the strain-free counterpart (35.97 μmol l−1 min−1) and other previously reported materials. Such superior performance of CSR-TiO2 stemmed from compressive strain, which can suppress the formation of reductive unsaturated sites for the O2 adsorption and enhance the reductive ability of atomic hydrogen (H*), favouring the O2 mono-hydrogenation pathway and bypassing the traditional surface-bound *OOH desorption pathway. The generated 1O2 could be utilized for the selective oxidation of thioanisole and its derivatives, offering a promising strategy for green organic synthesis.
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Acknowledgements
This work was supported by the National Key Research and Development Program of China (grant nos. 2021YFA1201701 to Y.Y. and 2022YFA1205601 to Y.Y.), the National Natural Science Foundation of China (grant nos. U22A20402 to L.Z.Z., 22102100 to Y.Y., 22206121 to J.D., 22306119 to Y.S. and 22476126 to Y.Y.), Shenzhen Science and Technology Program (grant no. JCYJ20220818095601002 to L.Z.Z.) and the Natural Science Foundation of Shanghai (grant no. 22ZR1431700 to Y.Y.). The authors acknowledge the support from the Max Planck−POSTECH−Hsinchu Center for Complex Phase Materials, the Instrumental Analysis Center of Shanghai Jiao Tong University, Instrumental Analysis Center of School of Environmental Science and Engineering, State Key Laboratory for Pollution Control and Resource Reuse, and Shiyanjia Lab for the help in characterizations and experimental measurements. The computations in this paper were run on the π 2.0 cluster supported by the Center for High Performance Computing at Shanghai Jiao Tong University.
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Y.Y. and L.Z.Z. conceived the idea. R.W. and J.D. carried out the sample synthesis, characterization and electrocatalytic measurements. R.W. performed the theoretical calculations. R.W., J.D., Y.Y. and L.Z.Z. wrote the paper. Z.H., C.C. and C.K. carried out the sXAS measurements. L.Z., Y.Z. and M.X. conducted TEM characterizations. G.Z. helped with the density functional theory (DFT) calculation. Y.S., J.W. and X.Z. offered help on the operando electrochemical ATR-IR. B.Z. and K.W. performed the EPR measurement. R.Z., Y.Z. and Y.S. took part in the operando Raman spectroscopy. All the authors discussed results and provided comments during the manuscript preparation.
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Nature Synthesis thanks W.-F. Lin and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. The Primary Handling Editor: is Alexandra Groves, in collaboration with the Nature Synthesis team.
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Wang, R., Dai, J., Zhao, L. et al. Compressive-strained rutile TiO2 enables O2 mono-hydrogenation for singlet oxygen electrosynthesis. Nat. Synth 4, 754–764 (2025). https://doi.org/10.1038/s44160-025-00756-0
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DOI: https://doi.org/10.1038/s44160-025-00756-0
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