Tianying Liu

All Publications

• Operando Spectroscopic Analysis of Photovoltage Generation in Hematite Photoanodes JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Oldham, L. I., Benetti, D., Liu, T., Wang, D., Durrant, J. R. 2026; 148 (24): 24964-24973

  Abstract

  Solar-driven water splitting requires sufficient photovoltage to drive both water oxidation and proton reduction. Understanding the factors driving and limiting photovoltage generation is therefore crucial to optimizing photoelectrode design but has proven challenging to determine under operando conditions for photoanodes driving slow multiredox reactions such as water oxidation. In this work, operando optical spectroscopy is employed to measure the hole quasi-Fermi level (EF,p) position in model hematite photoanodes as a function of applied bias and light intensity. The quasi-Fermi level splitting determined from these data are shown be in excellent agreement with the directly measured photovoltages, demonstrating the primarily electrochemical rather than primarily electrostatic origin of photovoltage in these photoelectrodes. EF,p pinning is observed at low light intensities and biases, indicative of hole trap states lying ∼0.2 eV above the valence band edge with a density of ∼1 nm-2. Hole accumulation in these trap states is correlated with first order water oxidation. At higher light intensities and/or more anodic bias, EF,p becomes unpinned, assigned to saturation of these trap states, and correlated with the onset of third order water oxidation to molecular oxygen. Comparison with rate law analyses for other photoanodes indicates that such hole trap states may be a ubiquitous feature of metal oxides and suggests that materials processing strategies to suppress the density of such states would be a promising strategy to enhance photoanode performance.

  View details for DOI 10.1021/jacs.6c04274

  View details for Web of Science ID 001788386200001

  View details for PubMedID 42262481

  View details for PubMedCentralID PMC13307358

• Modulating coordinate site occupancy in high-entropy spinel electrocatalysts. Nature communications Baek, J., Hamkins, K. S., Li, Y., Garcia-Esparza, A. T., Liu, T., Kuo, C. T., Lee, J. S., Potter, A. W., Kim, S., Wang, Y., Ding, H., Li, J., Zhuo, Z., Guo, J., Bajdich, M., Zheng, X. 2026

  Abstract

  High entropy spinel oxides provide a versatile platform for electrocatalysis because multiple metal cations can be incorporated into a single crystalline lattice, enabling tunable electronic structures. However, controlling how these cations distribute between tetrahedral and octahedral coordination sites remains a major challenge, limiting rational catalyst design. Here, we modulate cation coordination site occupancy between tetrahedral and octahedral sites in a Co-Fe-Cr-Mn-Ni framework by introducing a sixth cation (Zn, Ga, Mg, or Al) with distinct site preference energies. Using density functional theory, synchrotron X-ray absorption spectroscopy, and magnetic circular dichroism, we demonstrate that Zn preferentially occupies tetrahedral sites, driving increased octahedral occupancy of cobalt. This redistribution increases the population of octahedrally coordinated cobalt in mixed oxidation states, enhances electrical conductivity, and improves oxygen evolution reaction activity. Our findings establish coordination site occupancy as a critical design parameter, providing a strategic pathway for tailoring multicomponent spinel electrocatalysts with optimized performance.

  View details for DOI 10.1038/s41467-026-70982-3

  View details for PubMedID 41862500

• Investigating the Adsorption-Desorption Kinetics of a Molecular Water Oxidation Catalyst at an Electrode Interface JOURNAL OF PHYSICAL CHEMISTRY LETTERS Chen, B., Zhang, H., Zhang, R., Liu, T., Shin, D., Wang, D., Waegele, M. M. 2026

  Abstract

  Probing the dynamics of molecular catalysts at electrode-electrolyte interfaces is essential for understanding catalytic mechanisms. Structure-specific spectroscopic methods are particularly powerful for examining electrocatalytic interfaces but are mostly used under steady-state conditions. Herein, we combined surface-enhanced infrared absorption spectroscopy (SEIRAS) with phase-sensitive detection (PSD) to investigate the dynamics of a molecular Ir-based water oxidation catalyst at the Au-electrolyte interface. We found that the amplitude of the absorbance of the catalyst is anticorrelated to that of interfacial water. This anticorrelation can be understood by the adsorption of the electrooxidized catalyst on the electrode and concurrent displacement of interfacial water. The infrared signals from the interface exhibit an increasing phase lag with respect to the electrode potential with an increasing scan rate of the potential. Kinetic modeling suggests that the potential-dependent adsorption-desorption kinetics of the molecular catalyst on the electrode gives rise to this phase lag. This study shows that PSD-SEIRAS is a powerful tool for investigating the interfacial dynamics of electrocatalytic systems.

  View details for DOI 10.1021/acs.jpclett.5c03574

  View details for Web of Science ID 001691798400001

  View details for PubMedID 41696881

• Gerischer Electrochemistry Today ACS ENERGY LETTERS Sambur, J. B., Kaufman, A. J., Montoya-Castillo, A., Kundman, A., Nozik, A. J., Descarpentrie, A. G., Jana, A., Tews, A., Banik, A., Martindale, B. C. M., Debruine, B., Parkinson, B. A., Frisbie, C., Tossi, C., Hallock, C. D., Esposito, D. V., Lustig, D. R., Ingram, D., Seo, D., Solanki, D., Wang, D., Ratcliff, E. L., Houle, F. A., Toma, F. M., Zhu, G., Moore, G. F., Meyer, G. J., Liu, H., Begum, H., Schneidewind, J., Cahoon, J. F., Mayer, J. M., Van De Lagemaat, J., Brinker, J. R., Dempsey, J. L., Mendes, J., Diederich, J., Hart, J. N., Brinkert, K., Rajeshwar, K., Choi, K., Berben, L. A., Salvi, M., Spitler, M. T., Rose, M. J., Lewis, N. S., Gomez, N. A., Maurya, O., Aghadiuno, P. O., Kamat, P. V., Evans, R., Almaraz, R., Sampaio, R. N., Coridan, R. H., Van De Krol, R., Suo, S., Magpantay, S. V., Bae, S., Cushing, S., Ardo, S., Boettcher, S. W., Hu, S., Maldonado, S., Liu, T., Cuk, T., Hannappel, T., Sayer, T., Arthur, T., Deutsch, T. G., Streibel, V., Stinson, W. D. H., Jaegermann, W., Surendranath, Y., Mi, Z., Ye, Z. 2025; 10 (12): 6578-6595

  View details for DOI 10.1021/acsenergylett.5c02966

  View details for Web of Science ID 001636344700001

• Effect of Electrolyte Ions on Iridium Oxide-Based Water Oxidation Catalysis ACS CATALYSIS Chen, B., Wang, P., Shin, D., Li, W., Liu, T., Waegele, M. M., Wang, D. 2025

  View details for DOI 10.1021/acscatal.5c03970

  View details for Web of Science ID 001571004700001