Overall photocatalytic water splitting is one of the most sought after processes for sustainable solar-to-chemical energy conversion. The efficiency of this process strongly depends on charge carrier recombination and interaction with surface adsorbates at different time scales. Here, we investigated how hydration of TiO P25 affects dynamics of photogenerated electrons at the millisecond to minute time scale characteristic for chemical reactions. We used rapid scan diffuse-reflectance infrared Fourier transform spectroscopy (DRIFTS). The decay of photogenerated electron absorption was substantially slower in the presence of associated water. For hydrated samples, the charge carrier recombination rates followed an Arrhenius-type behavior in the temperature range of 273-423 K; these became temperature-independent when the material was dehydrated at temperatures above 423 K or cooled below 273 K. A DFT+ analysis revealed that hydrogen bonding with adsorbed water stabilizes surface-trapped holes at anatase TiO(101) facet and lowers the barriers for hole migration. Hence, hole mobility should be higher in the hydrated material than in the dehydrated system. This demonstrates that adsorbed associated water can efficiently stabilize photogenerated charge carriers in nanocrystalline TiO and suppress their recombination at the time scale up to minutes.
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http://dx.doi.org/10.1021/acs.jpcc.7b00472 | DOI Listing |
Nat Commun
December 2024
Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea.
Fermi polarons are emerging quasiparticles when a bosonic impurity immersed in a fermionic bath. Depending on the boson-fermion interaction strength, the Fermi-polaron resonances exhibit either attractive or repulsive interactions, which impose further experimental challenges on understanding the subtle light-driven dynamics. Here, we report the light-driven dynamics of attractive and repulsive Fermi polarons in monolayer WSe devices.
View Article and Find Full Text PDFAdv Mater
December 2024
Academy for Advanced Interdisciplinary Studies and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen, 518055, P. R. China.
Concurrent superconductivity and negative photoconductivity (NPC) are rarely observed. Here, the discovery in PbSeTe of superconductivity and photoconductivity transitions between positive photoconductivity (PPC) and NPC during compression is reported to ≈40 GPa and subsequent decompression, which are also accompanied by reversible structure transitions (3D Fm m ⇌ 2D Pnma ⇌ 3D Pm m). Superconductivity with a maximum T of ≈6.
View Article and Find Full Text PDFAdv Mater
December 2024
Hefei National Research Center for Physical Sciences at the Microscale, Department of Materials Science and Engineering, CAS Key Laboratory of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
The critical challenges in developing ultralow-temperature proton-based energy storage systems are enhancing the diffusion kinetics of charge carriers and inhibiting water-triggered interfacial side reactions between electrolytes and electrodes. Here an acid-salt hybrid electrolyte with a stable anion-cation-HO solvation structure that realizes unconventional proton transport at ultralow temperature is shown, which is crucial for electrodes and devices to achieve high rate-capacity and stable interface compatibility with electrodes. Through multiscale simulations and experimental investigations in the electrolyte employing ZnCl introduced into 0.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Department of Chemistry, University of Ulsan, Ulsan 44610, Republic of Korea. Electronic address:
The improper handling and uncontrolled discharge of toxic organic dyes result in significant adverse effects on both human health and the environment. This study investigates the fabrication of SnO₂, yttrium and cobalt dual-doped SnO₂ (YCSn), chitosan-capped SnO₂ (CS*Sn), and chitosan-capped yttrium and cobalt dual-doped SnO₂ (CS*YCSn) nanoparticles using a one-step coprecipitation method for the photocatalytic degradation of methylene blue (MB) under visible light irradiation. Characterization techniques including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM), and ultraviolet-visible (UV-Vis) spectrophotometry confirm the successful synthesis of biodegradable CS*YCSn nanoparticles.
View Article and Find Full Text PDFWater Res
December 2024
School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, 646000, China. Electronic address:
Synergism of piezoelectricity and photocatalysis is an effective approach for pollutant degradation and removal, and has garnered considerable attention. Nonetheless, great challenges still remain in recombination and slow migration rate of charge carriers. For response, a novel Three-in-One strategy based on MXene/ZnS/FeO (MZF) was developed to enhance the piezoelectric photocatalytic activity via achieving a triple effect: Dual Schottky heterojunction, Interface electric field, and Oxygen vacancy.
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