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Facet-Dependent Photocatalytic Behaviors of ZnS-Decorated Cu <sub/>2</sub> O Polyhedra Arising from Tunable Interfacial Band Alignment
摘要： ZnS particles were grown over Cu2O cubes, octahedra, and rhombic dodecahedra for examination of their facet-dependent photocatalytic behaviors. After ZnS growth, Cu2O cubes stay photocatalytically inactive. ZnS-decorated Cu2O octahedra show enhanced photocatalytic activity resulting from better charge carrier separation upon photoexcitation. Surprisingly, Cu2O rhombic dodecahedra give greatly suppressed photocatalytic activity after ZnS deposition. Electron paramagnetic resonance (EPR) spectra agree with these experimental observations. Time-resolved photoluminescence (TRPL) profiles provide charge transfer insights. The decrease in the photocatalytic activity is attributed to an unfavorable band alignment caused by significant band bending within the Cu2O (110)/ZnS (200) plane interface. A modified Cu2O–ZnS band diagram is presented. Density functional theory (DFT) calculations generating plane-specific band energy diagrams of Cu2O and ZnS match well with the experimental results, showing charge transfer across the Cu2O (110)/ZnS (200) plane interface would not happen. This example further illustrates that the actual photocatalysis outcome for semiconductor heterojunctions cannot be assumed because interfacial charge transfer is strongly facet-dependent.
关键词： interfacial charge transfer,zinc sulfide,cuprous oxide,facet-dependent properties,heterojunctions,band alignment
更新于2025-09-23 15:23:52
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Ultrafast Interfacial Charge Transfer of Cesium Lead Halide Perovskite Films CsPbX3 (X = Cl, Br, I) with Different Halogen Mixing
摘要： Understanding the interfacial charge transfer of the photoinduced transients of all-inorganic cesium lead halide perovskites (CsPbX3; X = Cl, Br, I) is critical for their photovoltaic applications. Ultrafast dynamics can provide comprehensive information about the transient behavior of the carriers and their transfer mechanism in the materials. In this work, the interfacial charge transfer of CsPbX3 films assembled with TiO2 with different halogen doping ratios was studied using femtosecond transient absorption (TA) spectroscopy combined with global analysis. Four subsequent decay processes after photoexcitation were obtained, including hot carrier cooling, free exciton forming, electron transfer, and charge recombination. The results indicate that the time constant of the interfacial electron transfer varies with the location of the trap state of these perovskites and the relative energy of CBs in the perovskite and TiO2 and that the time constant of the charge recombination can be attributed to the electron–hole interactions. These interpretations are supported by calculations based on first-principles density functional theory (DFT). Greater iodine doping in such perovskite CsPbX3/TiO2 systems increases the time constants of the electron transfer and charge recombination, which suggests that all-inorganic perovskite CsPbX3 with a high iodine content is favorable for improving the power conversion efficiency of solar cells.
关键词： cesium lead halide perovskite,transient absorption,global analysis,interfacial charge transfer
更新于2025-09-23 15:21:01
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Improving Interfacial Charge-Transfer Transitions in Nb-Doped TiO2 Electrodes with 7,7,8,8-Tetracyanoquinodimethane
摘要： Interfacial charge-transfer (ICT) transitions involved in charge-separation mechanisms are expected to enable efficient photovoltaic conversions through one-step charge-separation processes. With this in mind, the charge-transfer complex fabricated from TiO2 nanoparticles and 7,7,8,8-tetracyanoquinodimethane (TCNQ) has been applied to dye-sensitized solar cells. However, rapid carrier recombination from the conduction band of TiO2 to the highest occupied molecular orbital (HOMO) of TCNQ remains a major issue for this complex. In this study, to inhibit surface-complex recombinations, we prepared Nb-doped TiO2 nanoparticles with different atomic ratios for enhanced electron transport. To investigate the effects of doping on electron injection through ICT transitions, these materials were examined as photoelectrodes. When TiO2 was doped with 1.5 mol % Nb, the Fermi level of the TiO2 electrode shifted toward the conduction band minimum, which improved electron back-contact toward the HOMO of TCNQ. The enhancement in electron transport led to increases in both short circuit current and open circuit voltage, resulting in a slight (1.1% to 1.3%) improvement in photovoltaic conversion efficiency compared to undoped TiO2. Such control of electron transport within the photoelectrode is attributed to improvements in electron injection through ICT transitions.
关键词： photovoltaic conversion,Nb-doped TiO2,interfacial charge-transfer transition,7,7,8,8-tetracyanoquinodimethane
更新于2025-09-23 15:21:01
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Enhancing interfacial charge transfer on novel 3D/1D multidimensional MoS2/TiO2 heterojunction toward efficient photoelectrocatalytic removal of levofloxacin
摘要： Structure-controlled visible light driven photo-anode with high catalytic performance, plays important roles in environmental pollutants treatment. In this work, a mild hydrothermal assisted anodization approach has been reported to design an integrated self-assembled 3D flower-like MoS2/1D TiO2 nanotube arrays (NTAs) hierarchical electrode. The constructed multidimensional electrode not only broadened the absorption spectrum response range but also promoted rapidly electron-hole pairs separation, exhibiting the excellent photoelectron catalytic (PEC) performance and stability in the degradation of target pollutants, which the photocurrent conversion efficiency was 6.5 times higher than that of pure TiO2. Furtherly, a comprehensive mechanism was proposed to explain the charge transfer on the interface of intimate integration of 3D/1D hybrid nanostructure towards PEC properties in terms of the energy band structures and DFT. Furthermore, the photo-generated active species (?OH and ?O2-) have been proved by electron paramagnetic resonance spectroscopy and fluorescence probe over the composites. Thus, this work could provide an effective strategy to design multidimensional coupled heterojunction materials toward solar energy conversion for environmental purification.
关键词： Interfacial charge transfer,Photoelectrocatalytic,Active radicals,DFT,3D/1D hybrid nanostructures
更新于2025-09-23 15:21:01
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The improved electrochemiluminescence behavior of glassy carbon electrode via in situ chemical bonding modification
摘要： An in situ chemical bonding method is developed for the electrochemiluminescence (ECL) modification of the oxidized glassy carbon electrode (GCEox). Bare GCE has been activated here via a fierce oxidizing etching to form GCEox. GCEox with numerous cracks and oxygen containing groups exhibits a negatively charged surface, which is tending to attract and react with the specific molecules to form chemical bonds. An ECL molecule Ru-L1 was synthesized and in situ bonded on GCEox surface to fabricate Ru-GCEox. The proposed chemical bonding modification eliminates the interface resistance to improve the electron transfer rate between Ru-L1 and the surface of GCE, which has been demonstrated by the better reversibility of Ru-GCEox than the traditional modified GCEs. The improvement of the ECL behavior of Ru-GCEox is also confirmed by its lower ECL potential than the traditional modified GCEs. Ru-GCEox is reusable to response α-naphthol with an ultrahigh sensitivity for its excellent ECL stability and scraping resistance, which decreases the consumption of Ru-L1. The successful fabrication of Ru-GCEox indicates the method of in situ chemical modification for GCEox can be applied to fabricate various glassy carbon-based sensors via coupling with various specific molecules.
关键词： ruthenium (II) complex,glassy carbon,the interfacial charge transfer,electrochemiluminescence
更新于2025-09-19 17:15:36
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Synergistic effect of surface oxygen vacancies and interfacial charge transfer on Fe(III)/Bi2MoO6 for efficient photocatalysis
摘要： Novel Fe(III) clusters grafted Bi2MoO6 nanosheets with surface oxygen vacancies (denoted as F/BMO-SOVs) heterostructured composite have been firstly fabricated via a reliable calcination process combined with impregnation approach. The surface oxygen vacancies (SOVs) in Bi2MoO6 were formed due to controlled calcination process. The presence of Fe (III) clusters was confirmed by HRTEM, XPS, and UV-Vis DRS. Under visible light irradiation, the optimum molar ratio of 15% F/BMO-SOVs achieved 93.4% degradation efficiency of phenol within 180 min, representing nearly 80 times higher activity than the pure Bi2MoO6, confirmed by both absorption spectrum and TOC measurement. The dramatically enhanced photocatalytic activity is attributed to the synergistic effect between the SOVs, Fe(III) clusters and Bi2MoO6, which not only narrows the band gap, improving the visible light response ability, but also facilitates the direct interfacial charge transfer (IFCT) from the SOVs to the surface Fe(III) clusters, greatly promoting the efficient separation of photogenerated electron-hole pairs. According to the trapping experiments and ESR measurements results, ·O2-, ·OH-, and h+ all participated in the phenol photodegradation process over F/BMO-SOVs. Thus, this work not only provides a synergistic effect between SOVs, Fe(III) clusters and Bi2MoO6 involving an IFCT process, but also proposes an efficient approach to fabricating highly active photocatalysts in environmental remediation and solar fuel synthesis.
关键词： Surface oxygen vacancy,Phenol degradation,Synergistic effect,Interfacial charge transfer,Heterostructured Fe(III)/Bi2MoO6
更新于2025-09-19 17:15:36
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Efficiency enhancement of pyridinium ylide dye-sensitized solar cells by introduction of benzothiadiazolyl chromophore: A computational study
摘要： Organic pyridinium ylide sensitizers NO108-NO111 with different anchoring groups show attractive applications in dye-sensitized solar cells. To elucidate the intrinsic sensitization mechanism of this series of dyes, theoretical calculations of electrochemical and spectroscopic properties for free and adsorbed ylides have been performed. Moreover, to prescreen and optimize suitable candidates for pyridinium ylide cells, the benzothiadiazole (BTD) group is introduced in the best-performing ylide NO111, and the afforded dye is coded as NO111-1. Comparing pyiridine-N-oxide in NO108, diethylmalonate in NO111 shows superior properties in terms of interfacial charge transfer, anti-aggregation, and long-term stability. It also demonstrates that the novel designed NO111-1-sensitized film possesses higher average theoretical maximum limit of short-circuit photocurrent density (≈ 23 mA/cm2), and slower parasitic recombination than NO111 one. This result is expected to further reveal the effects of anchoring groups on properties of dyes, and is helpful for the design of more efficient pyridinium ylide dyes.
关键词： Self-assembly,Pyridinium ylide dye,Anchoring group,Interfacial charge transfer,Light harvesting
更新于2025-09-12 10:27:22
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Interfacial charge transfer between CsPbBr <sub/>3</sub> quantum dots and ITO nanoparticles revealed by single-dot photoluminescence spectroscopy
摘要： The interfacial charge transfer between single CsPbBr3 perovskite quantum dots (QDs) and indium tin oxide (ITO) is investigated by single-dot photoluminescence spectroscopy. It is found that when the Fermi level of single perovskite QDs aligns with that of ITO nanoparticles, the QD surface cannot be charged by the ITO through interfacial electron transfer. Therefore, the QD/ITO system with Fermi level alignments can exclude exciton nonradiative recombination processes involving the additional surface electrons, such as the exciton Auger recombination and the valence band hole transfer processes. Hence the photovoltaic devices based on perovskite QD/ITO system with the Fermi level alignments have the improved photoelectric conversion efficiency.
关键词： Fermi level alignments,single-dot photoluminescence spectroscopy,photoelectric conversion efficiency,interfacial charge transfer,CsPbBr3 quantum dots,ITO nanoparticles
更新于2025-09-11 14:15:04