Weilai Yu

All Publications

• Environmentally stable and stretchable polymer electronics enabled by surface-tethered nanostructured molecular-level protection. Nature nanotechnology Zheng, Y., Michalek, L., Liu, Q., Wu, Y., Kim, H., Sayavong, P., Yu, W., Zhong, D., Zhao, C., Yu, Z., Chiong, J. A., Gong, H., Ji, X., Liu, D., Zhang, S., Prine, N., Zhang, Z., Wang, W., Tok, J. B., Gu, X., Cui, Y., Kang, J., Bao, Z. 2023

  Abstract

  Stretchable polymer semiconductors (PSCs) are essential for soft stretchable electronics. However, their environmental stability remains a longstanding concern. Here we report a surface-tethered stretchable molecular protecting layer to realize stretchable polymer electronics that are stable in direct contact with physiological fluids, containing water, ions and biofluids. This is achieved through the covalent functionalization of fluoroalkyl chains onto a stretchable PSC film surface to form densely packed nanostructures. The nanostructured fluorinated molecular protection layer (FMPL) improves the PSC operational stability over an extended period of 82 days and maintains its protection under mechanical deformation. We attribute the ability of FMPL to block water absorption and diffusion to its hydrophobicity and high fluorination surface density. The protection effect of the FMPL (~6 nm thickness) outperforms various micrometre-thick stretchable polymer encapsulants, leading to a stable PSC charge carrier mobility of ~1 cm2 V-1 s-1 in harsh environments such as in 85-90%-humidity air for 56 days or in water or artificial sweat for 42 days (as a benchmark, the unprotected PSC mobility degraded to 10-6 cm2 V-1 s-1 in the same period). The FMPL also improved the PSC stability against photo-oxidative degradation in air. Overall, we believe that our surface tethering of the nanostructured FMPL is a promising approach to achieve highly environmentally stable and stretchable polymer electronics.

  View details for DOI 10.1038/s41565-023-01418-y

  View details for PubMedID 37322142

• A salt-philic, solvent-phobic interfacial coating design for lithium metal electrodes NATURE ENERGY Huang, Z., Lai, J., Liao, S., Yu, Z., Chen, Y., Yu, W., Gong, H., Gao, X., Yang, Y., Qin, J., Cui, Y., Bao, Z. 2023

  View details for DOI 10.1038/s41560-023-01252-5

  View details for Web of Science ID 000975216800001

• Understanding the stability of semiconducting photocathodes for solar water splitting CURRENT OPINION IN ELECTROCHEMISTRY Yu, W. 2023; 39

  View details for DOI 10.1016/j.coelec.2023.101262

  View details for Web of Science ID 000962447800001

• A general interfacial-energetics-tuning strategy for enhanced artificial photosynthesis. Nature communications Liu, T., Pan, Z., Kato, K., Vequizo, J. J., Yanagi, R., Zheng, X., Yu, W., Yamakata, A., Chen, B., Hu, S., Katayama, K., Chu, C. 2022; 13 (1): 7783

  Abstract

  The demands for cost-effective solar fuels have triggered extensive research in artificial photosynthesis, yet the efforts in designing high-performance particulate photocatalysts are largely impeded by inefficient charge separation. Because charge separation in a particulate photocatalyst is driven by asymmetric interfacial energetics between its reduction and oxidation sites, enhancing this process demands nanoscale tuning of interfacial energetics on the prerequisite of not impairing the kinetics and selectivity for surface reactions. In this study, we realize this target with a general strategy involving the application of a core/shell type cocatalyst that is demonstrated on various photocatalytic systems. The promising H2O2 generation efficiency validate our perspective on tuning interfacial energetics for enhanced charge separation and photosynthesis performance. Particularly, this strategy is highlighted on a BiVO4 system for overall H2O2 photosynthesis with a solar-to-H2O2 conversion of 0.73%.

  View details for DOI 10.1038/s41467-022-35502-z

  View details for PubMedID 36526643

• Degradation and Speciation of Li Salts during XPS Analysis for Battery Research ACS ENERGY LETTERS Yu, W., Yu, Z., Cui, Y., Bao, Z. 2022; 7 (10): 3270-3275

  View details for DOI 10.1021/acsenergylett.2c01587

  View details for Web of Science ID 000895677900001

• Failure Modes of Platinized pn+-GaInP Photocathodes for Solar-Driven H2 Evolution. ACS applied materials & interfaces Yu, W., Buabthong, P., Young, J. L., Ifkovits, Z. P., Byrne, S. T., Steiner, M. A., Deutsch, T. G., Lewis, N. S. 2022

  Abstract

  The long-term stability for the hydrogen-evolution reaction (HER) of homojunction pn+-Ga0.52In0.48P photocathodes (band gap = 1.8 eV) with an electrodeposited Pt catalyst (pn+-GaInP/Pt) has been systematically evaluated in both acidic and alkaline electrolytes. Electrode dissolution during chronoamperometry was correlated with changes over time in the current density-potential (J-E) behavior to reveal the underlying failure mechanism. Pristine pn+-GaInP/Pt photocathodes yielded an open-circuit photopotential (Eoc) as positive as >1.0 V vs the potential of the reversible hydrogen electrode (RHE) and a light-limited current density (Jph) of >12 mA cm-2 (1-sun illumination). However, Eoc and Jph gradually degraded at either pH 0 or pH 14. The performance degradation was attributed to three different failure modes: (1) gradual thinning of the n+-emitter layer due to GaInP dissolution in acid; (2) active corrosion of the underlying GaAs substrate at positive potentials causing delamination of the upper GaInP epilayers; and (3) direct GaAs/electrolyte contact compromising the operational stability of the device. This work reveals the importance of both substrate stability and structural integrity of integrated photoelectrodes toward stable solar fuel generation.

  View details for DOI 10.1021/acsami.2c01845

  View details for PubMedID 35666827

• Tuning Fluorination of Linear Carbonate for Lithium-Ion Batteries JOURNAL OF THE ELECTROCHEMICAL SOCIETY Yu, Z., Yu, W., Chen, Y., Mondonico, L., Xiao, X., Zheng, Y., Liu, F., Hung, S. T., Cui, Y., Bao, Z. 2022; 169 (4)

  View details for DOI 10.1149/1945-7111/ac67f5

  View details for Web of Science ID 000788721400001

• Catalytic open-circuit passivation by thin metal oxide films of p-Si anodes in aqueous alkaline electrolytes ENERGY & ENVIRONMENTAL SCIENCE Fu, H. J., Buabthong, P., Ifkovits, Z., Yu, W., Brunschwig, B. S., Lewis, N. S. 2021

  View details for DOI 10.1039/d1ee03040j

  View details for Web of Science ID 000728258100001

• Understanding the Stability of Etched or Platinized p-GaInP Photocathodes for Solar-Driven H2 Evolution. ACS applied materials & interfaces Yu, W., Young, J. L., Deutsch, T. G., Lewis, N. S. 2021

  Abstract

  The long-term stability in acidic or alkaline aqueous electrolytes of p-Ga0.52In0.48P photocathodes, with a band gap of 1.8 eV, for the solar-driven hydrogen-evolution reaction (HER) has been evaluated from a thermodynamic, kinetic, and mechanistic perspective. At either pH 0 or pH 14, etched p-GaInP electrodes corroded cathodically under illumination and formed metallic In0 on the photoelectrode surface. In contrast, under the same conditions, electrodeposition of Pt facilitated the HER kinetics and stabilized p-GaInP/Pt photoelectrodes against such cathodic decomposition. When held at 0 V versus the reversible hydrogen electrode, p-GaInP/Pt electrodes in either pH = 0 or pH = 14 exhibited stable current densities (J) of -9 mA cm-2 for hundreds of hours under simulated 1 sun illumination. During the stability tests, the current density-potential (J-E) characteristics of the p-GaInP/Pt photoelectrodes degraded due to pH-dependent changes in the surface chemistry of the photocathode. This work provides a fundamental understanding of the stability and corrosion mechanisms of p-GaInP photocathodes that constitute a promising top light absorber for tandem solar-fuel generators.

  View details for DOI 10.1021/acsami.1c18243

  View details for PubMedID 34821500

• Investigations of the stability of etched or platinized p-InP(100) photocathodes for solar-driven hydrogen evolution in acidic or alkaline aqueous electrolytes ENERGY & ENVIRONMENTAL SCIENCE Yu, W., Richter, M. H., Buabthong, P., Moreno-Hernandez, I. A., Read, C. G., Simonoff, E., Brunschwig, B. S., Lewis, N. S. 2021

  View details for DOI 10.1039/d1ee02809j

  View details for Web of Science ID 000707161300001

• Mixed Metal Oxide Electrodes and the Chlorine Evolution Reaction JOURNAL OF PHYSICAL CHEMISTRY C Dong, H., Yu, W., Hoffmann, M. R. 2021; 125 (38): 20745-20761

  View details for DOI 10.1021/acs.jpcc.1c05671

  View details for Web of Science ID 000704295900002

• Investigations of the stability of GaAs for photoelectrochemical H-2 evolution in acidic or alkaline aqueous electrolytes JOURNAL OF MATERIALS CHEMISTRY A Yu, W., Richter, M. H., Simonoff, E., Brunschwig, B. S., Lewis, N. S. 2021; 9 (40): 22958-22972

  View details for DOI 10.1039/d1ta04145b

  View details for Web of Science ID 000703234700001

• Origin of the Electrical Barrier in Electrolessly Deposited Platinum Nanoparticles on p-Si Surfaces JOURNAL OF PHYSICAL CHEMISTRY C Nunez, P., Caban-Acevedo, M., Yu, W., Richter, M. H., Kennedy, K., Villarino, A., Brunschwig, B. S., Lewis, N. S. 2021; 125 (32): 17660-17670

  View details for DOI 10.1021/acs.jpcc.1c03072

  View details for Web of Science ID 000687714800008

• Cathodic NH(4)(+)leaching of nitrogen impurities in CoMo thin-film electrodes in aqueous acidic solutions SUSTAINABLE ENERGY & FUELS Yu, W., Buabthong, P., Read, C. G., Dalleska, N. F., Lewis, N. S., Lewerenz, H., Gray, H. B., Brinkert, K. 2020; 4 (10): 5080-5087

  View details for DOI 10.1039/d0se00674b

  View details for Web of Science ID 000573449300014