Prolonged Lifetime Research Articles

What does cancer screening have to do with tomato growing?

Cancer screening is considered to be a major strategy for combatting cancer. The United States Preventive Services Task Force (USPSTF) recommends screening for five cancers, but the strength of evidence about the effectiveness of screening is limited. To gain insights into the efficacy of early detection requires prospective, blinded, placebo-controlled clinical trials with decades of follow-up and inclusion of millions of participants. Recently, Bretthauer etal. estimated lifetime gained with cancer screening tests by using a meta-analysis of 18 large randomized clinical trials which included more than two million subjects. They asked if cancer screening tests are saving lives and how much life is extended due to commonly used cancer screening tests. Colorectal cancer screening with sigmoidoscopy prolonged lifetime by 110days, while fecal testing and mammography screening did not prolong life. A modest extension of 37days was noted for prostate cancer screening with prostate-specific antigen testing and 107days with lung cancer screening using computed tomography, but these estimates were not statistically significant. The authors concluded that current cancer screening strategies do not significantly prolong life. Based on these data, and the known biological behavior of some cancers, we hypothesized that the current strategies of treating cancer, after detection, could be modified to avoid the side effects of screening, which is a major determinant of the patient's overall survival.

Expanded Negative Electrostatic Network-Assisted Seawater Oxidation and High-Salinity Seawater Reutilization.

Coastal/offshore renewable energy sources combined with seawater splitting offer an attractive means for large-scale H2 electrosynthesis in the future. However, designing anodes proves rather challenging, as surface chlorine chemistry must be blocked, particularly at high current densities (J). Additionally, waste seawater with increased salinity produced after long-term electrolysis would impair the whole process sustainability. Here, we convert seawater to O2 selectively, on hydroxides, by building phytate-based expanded negative electrostatic networks (ENENs) with electrostatically repulsive capacities and higher negative charge coverage ranges than those of common inorganic polyatomic anions. With surface ENENs, even typically unstable CoFe hydroxides perform nicely toward alkaline seawater oxidation at activities of >1 A cm-2. CoFe hydroxides with phytate-based ENENs exhibit prolonged lifespans of 1000 h at J of 1 A cm-2 and 900 h at J of 2 A cm-2 and thus rival the best seawater oxidation anodes. Direct introduction of trace phytates to seawater weakens corrosion tendency on conventional CoFe hydroxides as well, extending the life of hydroxides by ∼28 times at J of 2 A cm-2. A wide range of materials all obtain prolonged lifetimes in the presence of ENENs, validating universal applicability. Mechanisms are studied using theoretical computations under working conditions and ex situ/in situ characterizations. We demonstrate a potentially viable way to sustainably reutilize high-salinity wastewater, which is a long-standing but neglected issue. Series-connected devices exhibit good resistance to low temperature operation and are more eco-friendly than current organic electrolyte-based energy storage devices.

Ultrafast dynamics of mCP and Br-mCP: Insights from transient absorption spectroscopy

Heavy atom activated organic room-temperature phosphorescence (RTP) has attracted considerable interest due to its high phosphorescence quantum yield and prolonged lifetime. This research provides a detailed analysis of the transient absorption spectroscopy of 1,3-Bis(N-carbazolyl)benzene (mCP) and 9,9'-(5-Bromo-1,3-phenylene)bis(9H-carbazole) (Br-mCP) in toluene solution. In the femtosecond transient absorption (fs-TA) spectroscopy of mCP, the excited state absorption (ESA) signal decreases at 630 nm while the triplet-triplet absorption (TTA) signal increases at 420 nm. Meanwhile, the isosbestic point observed at 455 nm indicates an intersystem crossing (ISC) lifetime of 15.4 ns. Moving on to the nanosecond transient absorption (ns-TA) spectroscopy, the TTA signal reaches its peak at 27.3 ns before decreasing, with the triplet lifetime of mCP measured at 2.8 μs. Br-mCP exhibits a similar dynamic evolution to mCP, but with a quicker ISC process (9.4 ns) and a longer triplet lifetime (3.9 μs). The quicker ISC process in Br-mCP is ascribed to the presence of heavy atom in the molecular structure, leading to an enhanced spin-orbit coupling constant (ξ(S1, T3)Br-mCP = 1.371 cm-1 > ξ(S1, T4)mCP = 0.060 cm-1). The prolonged triplet lifetime of Br-mCP (3.9 μs > 2.8 μs) results from its lower reorganization energy, effectively reducing non-radiative vibrational energy losses within the molecule. This work significantly enhances our understanding of RTP materials incorporating heavy atoms.

Enhancing the optoelectronic properties of SnS via mixed-phase heterostructure engineering.

SnS holds great promise in optoelectronics, especially in photovoltaic devices, due to its exceptional intrinsic electronic properties and optimal optical absorption. However, its prospective applications are often limited by structural instability or oxidation, leading to internal or external defect states. This study proposes a mixed-phase SnS/h-BN heterostructure to enhance chemical and thermal stability while preserving the intrinsic optoelectronic properties of SnS. High negative binding energy and ab initio molecular dynamics simulations confirm the structural and thermal stability of the heterostructure up to 600 K. The heterostructure exhibits a type-I band alignment with an indirect density functional theory (DFT) band gap of 1.38 eV, corrected to 2.20 eV using Green's function with screened Coulomb potential (GW) calculations. The vertical intralayer electric field, resulting from non-uniformity in charge dynamics within the heterostructure, influences the SnS bound excitons, causing reduction in their binding energies. The weakly bound excitons indicate effective charge separation, charge transport augmentation, and a prolonged recombination lifetime. The interface effectively combines the excellent light-harvesting capabilities of SnS with the remarkable stability of h-BN, retaining the desirable optoelectronic properties of SnS while offering enhanced charge transport and stability.

Identification of Two-Dimensional Interlayer Excitons and Their Valley Polarization in MoSe2/WSe2 Heterostructure with h-BN Spacer Layer.

Interlayer excitons (IXs) in the heterostructure of monolayer transition metal dichalcogenides (TMDs) are considered as a promising platform to study fundamental exciton physics and for potential applications of next generation optoelectronic devices. The IXs trapped in the moiré potential in a twisted monolayer TMD heterostructure such as MoSe2/WSe2 form zero-dimensional (0D) moiré excitons. Introducing an atomically thin insulating layer between TMD monolayers in a twisted heterostructure would modulate the moiré potential landscape, thereby tuning 0D IXs into 2D IXs. However, the optical characteristics of IXs have not been elucidated. Here, we have experimentally investigated the significant optical characteristics arising from IXs in a MoSe2/h-BN/WSe2 heterostructure by optical spectroscopy. The experimental results of time-resolved photoluminescence spectroscopy combined with phenomenological rate equation analysis reveal that the radiative decay rate of IXs in the MoSe2/h-BN/WSe2 heterostructure changes as a function of temperature, which strongly suggests the emergence of 2D IXs by the modulation of potential. Moreover, we demonstrate the valley polarization arising from the prolonged valley relaxation lifetime of 2D IXs reaching 100 ns at low temperature, which is dominated by electron-hole exchange interactions. These findings provide us with an effective strategy to tailor the dimensionality of IXs and elucidate the desired optoelectronic response of IXs in monolayer semiconductor heterostructures.

Effect of the Appended Morpholinyl Group on Photophysical Behavior of Mono- and Bis-cyclometalated Terpyridine Iridium(III) Chromophores.

This paper provides extensive studies of [IrCl(Ph-py)(morph-C6H4-terpy-κ3N)]PF6 (1A), [Ir(Ph-py)2(morph-C6H4-terpy-κ2N)]PF6 (2A), [IrCl(Ph-py)(Ph-terpy-κ3N)]PF6 (1B), and [Ir(Ph-py)2(Ph-terpy-κ2N)]PF6 (2B) designed to demonstrate the possibility of controlling the photophysical properties of mono- and bis-cyclometalated complexes [IrCl(Ph-py)(R-C6H4-terpy-κ3N)]PF6 and [Ir(Ph-py)2(R-C6H4-terpy-κ2N)]PF6 through a remote electron-donating substituent introduced into the 4'-position of 2,2':6',2″-terpyridine (terpy) via the phenyl linker. The attachment of the morpholinyl (morph) group was evidenced to induce dramatic changes in the emission characteristics of the monocyclometalated Ir(III) systems with meridionally coordinated R-C6H4-terpy ligand (κ3N). In solution, the obtained complex [IrCl(Ph-py)(morph-C6H4-terpy-κ3N)]PF6 was found to be a rare example of dual-emissive Ir(III) systems. Within the series [Ir(Ph-py)2(R-C6H4-terpy-κ2N)]PF6 bearing the R-C6H4-terpy ligand bound to the central ion in a bidentate coordination mode, the appended electron-donating morpholinyl group induced a minor effect on the emission maximum, but it was found to be an effective tool for extending the excited-state lifetime, further prolonging with the increase of solvent polarity. The results of this work are of high significance for better understanding the push-pull effect and dual-emission phenomena in Ir-based luminophores, as well as developing chromophores with prolonged emission lifetimes.

Ultrafast Thermal Switching Enabled by Transient Polaritons.

Ultrafast thermal switches are pivotal for managing heat generated in advanced solid-state applications, including high-speed chiplets, thermo-optical modulators, and on-chip lasers. However, conventional phonon-based switches cannot meet the demand for picosecond-level response times, and existing near-field radiative thermal switches face challenges in efficiently modulating heat transfer across vacuum gaps. To overcome these limitations, we propose an ultrafast thermal switch design based on pump-driven transient polaritons in asymmetric terminals. Demonstrated with WSe2 and graphene, this approach achieves an impressive thermal switching ratio exceeding 10,000 with response times on the picosecond scale, outperforming current designs by at least 2 orders of magnitude. This exceptional performance is driven by dynamic polaritonic coupling between terminals, activated by ultrafast photoexcitation. Additionally, the WSe2 monolayer-based switch exhibits a laser cooling effect, enabled by enhanced carrier excitation efficiency and prolonged carrier lifetimes, introducing a disruptive mechanism for laser cooling. Our findings highlight the strong potential of photodriven transient polaritons in advancing ultrafast thermal switches and nanoscale cooling technologies.

Photoisomerization Dynamics of Azo-Escitalopram Using Surface Hopping and a Semiempirical Method.

The photoisomerization dynamics of azo-escitalopram, a synthetic photoswitchable inhibitor of the human serotonin transporter, is investigated in both gas-phase and water. We use the trajectory surface hopping method─as implemented in SHARC─interfaced with the floating occupation molecular orbital-configuration interaction semiempirical method to calculate on-the-fly energies, forces, and couplings. The inclusion of explicit water molecules is enabled using an electrostatic quantum mechanics/molecular mechanics framework. We find that the photoisomerization quantum yield of trans-azo-escitalopram is wavelength- and environment-dependent, with n → π* excitation yielding higher quantum yields than π → π* excitation. Additionally, we observe the formation of two distinct cis-isomers in the photoisomerization from the most thermodynamically stable trans-isomer, with formation rates influenced by both the excitation window and the surrounding environment. We predict longer excited-state lifetimes than those reported for azobenzene, suggesting that the escitalopram moiety contributes to prolonged lifetimes and slower torsional motions.

Engineering yolk-double-shell Au@CN@ZnIn2S4 architecture with enhanced photocatalytic properties.

The efficient utilization of light and the prolonged lifetime of photo-induced charge carriers are essential elements that contribute to superior photocatalytic activity. Yolk-shell nanostructures with porous shells and mobile cores offer significant structural advantages in achieving these goals. However, designing yolk-shell multicomponent nanocomposites with diverse architectures remains a persistent challenge. The present study involves the utilization of zinc indium sulfide (ZnIn2S4) flakes, which are uniformly incorporated into the yolk-shell Au@CN structure. The inclusion of ZnIn2S4 flakes in carbon nitride (CN) significantly enhances the performance of the overall system, allowing for efficient and rapid charge transfer. The uniform distribution of ZnIn2S4 flakes throughout the yolk-shell matrix ensures the catalytic activity is maximized, resulting in superior performance compared to conventional systems. The designed photocatalyst has a hollow interior which strengthens light absorption, a thin shell that shortens the electron migration distance, tight adhesion between shells, which makes it easier to separate and transfer carriers, and a movable Au core with localized surface plasmon resonance (LSPR) which can facilitate additional charge carrier generation for CN and ZnIn2S4. The yolk-shell microsphere composite of Au@CN@ZnIn2S4 shows a TC photodegradation rate of 72% within 2h, which is more than double the photodegradation rate of hollow CN and ZnIn2S4. The present study's experimental demonstrations valuable insights into the rational design of sophisticated metal-semiconductors double yolk-shell nanocrystals, particularly those composed of metal sulfides cocatalyst, for superior photocatalytic applications.

A-Site Ion Doping in Cs2AgBiBr6 Double Perovskite Films for Improved Optical and Photodetector Performance

Perovskite materials, as emerging semiconductors, have attracted significant attention for their exceptional optoelectronic properties, tunable bandgaps, ease of fabrication, and cost-effectiveness, making them promising candidates for next-generation optoelectronic devices. The all-inorganic perovskite Cs2AgBiBr6 distinguishes itself from other perovskite materials due to its remarkable optical absorption and emission properties, excellent stability, prolonged carrier recombination lifetime, and nontoxic characteristics. However, a deeper understanding of its unique luminescent properties and a further optimization of its structure and performance are still necessary. This study systematically investigates the optimization of Cs2AgBiBr6 double perovskite films through A-site Na+ doping. At an optimal Na+ doping concentration of 3.5% (Na0.07Cs1.93AgBiBr6), the film shows 1.4 times and 2.7 times enhancement in light absorption and photoluminescence intensity, compared to the undoped film. Low-temperature spectroscopy measurements indicate that Na0.07Cs1.93AgBiBr6 exhibits higher exciton binding energy and phonon energy. Based on Na0.07Cs1.93AgBiBr6, the photodetectors demonstrate significant performance improvements, with a high photocurrent response of 10−2 A, a photo-to-dark current ratio (PDCR) of 7.57 × 104, a responsivity (R) of 16.23 A/W, a detectivity (D*) of 2.92 × 1012 Jones, a linear dynamic range (LDR) of 98.75 dB, and a fast response time of 943 ms. This work provides a promising strategy for optimizing all-inorganic perovskite materials through doping and offers guidance for enhancing high-performance photodetectors.

Promoting the Efficiency of Room-Temperature Phosphorescence by Forming the Composite and Employing It for Fingerprint Detection.

Currently, carbon dots (CDs) with room-temperature phosphorescence (RTP) show bright prospects in multiple fields, owing to their tunable wavelengths and large Stokes shifts. Howbeit, obtaining the long-lived efficient RTP of CDs still encounters a different kind of challenge. Here, we originally prepared the carbon dots (CDs@β-GPA) with β-guanidinopropionic acid and diethylenetriamine pentamethylene phosphonic acid, and CDs@β-GPA exhibited the obvious green RTP when fixed on filter paper. Importantly, the introduction of boric acid (BA) into the carbon dots resulted in stabilized triplet excitons by forming the composite of CDs@β-GPA/BA through covalent coupling, and the optical band gap was effectively reduced and nonradiative transitions were inhibited, thus leading to a significantly prolonged phosphorescence lifetime of up to 1.35 s. Meanwhile, we also acquired the phosphorescent emission of CDs@β-GPA/BA excited by visible light. This strategy may broaden the approaches to produce a long-lifetime and high-efficiency RTP material. Moreover, CDs@β-GPA/BA was successfully employed in the fields of fingerprint detection and advanced information encryption.

A minimalist multifunctional nano-prodrug for drug resistance reverse and integration with PD-L1 mAb for enhanced immunotherapy of hepatocellular carcinoma

Clinical treatment of hepatocellular carcinoma (HCC) with 5-fluorouracil (5-FU), the primary anticancer agent, remains unsatisfactory due to the glutathione (GSH)-associated drug resistance and immunosuppressive microenvironment of HCC. To develop a facile yet robust strategy to overcome 5-FU resistance for enhanced immunotherapy treatment of HCC via all dimensional GSH exhaustion, we report in this study construction of a minimalist prodrug consisting of 5-FU linked to an indoleamine-(2,3)-dioxygenase (IDO) inhibitor (IND) via a disulfide bridge, FU-SS-IND that can further self-assemble into stabilized nanoparticles, FU-SS-IND NPs. Specifically, besides the disulfide linker-induced GSH exhaustion, IND inhibits GSH biosynthesis and enhances the effector function of T cells for turning a “cold” tumor to a “hot” one, which synergistically achieving a tumor inhibition rate (TIR) of 92.5% in a 5-FU resistant mice model. Most importantly, FU-SS-IND NPs could upregulate programmed death ligand 1 (PD-L1) expression on the surface of tumor cells, which enables facile combination with immune checkpoint blockade (ICB) for a ultimate prolonged survival lifetime of 5-FU-resistant tumors-bearing mice. Overall, the minimalist bioreducible nano-prodrug developed herein demonstrates great translatable potential for efficiently reversing drug resistance and enhancing immunotherapy of HCC.

Application of rare earth elements in dual-modality molecular probes.

The unique 4f subshell electronic structure of rare earth elements endows them with exceptional properties in electrical, magnetic, and optical domains. These properties include prolonged fluorescence lifetimes, large Stokes shifts, distinctive spectral bands, and strong resistance to photobleaching, making them ideal for the synthesis of molecular probes. Each imaging technique possesses unique advantages and specific applicabilities but also inherent limitations due to its operational principles. Dual-modality molecular probes effectively address these limitations, particularly in applications involving high-resolution Magnetic Resonance Imaging (MRI) such as MRI/OI, MRI/PET, MRI/CT, and MRI/US. This review summarizes the applications, advantages, challenges, and current research status of rare earth elements in these four dual imaging modalities, providing a theoretical basis for the future development and application of rare earth elements in the field of dual-modality molecular probes.

On the Ionization Tolerance of C20 Fullerene in Ground and Excited Electronic States in Planetary Nebulae

As the smallest member of the fullerene family, C20 is yet to be discovered in planetary nebulae. In this work, we present a quantum chemical study via density functional theory (DFT) and partially by the MP2 on the ionization tolerance of this molecule in the space environment. Considering that the ionization and excitation phenomena play key roles in demonstrating the lifetime of a molecule, we examined both ground and excited electronic-state potential energy surfaces (PES) of C20 and its cations C20q+. Our theoretical results indicate that the C20 cage tolerates a positive charge as high as 13+ by characterizing local minimum geometries on both the abovementioned electronic states. The results are backed by characterizing both C2012+ and C2013+ as local minimum geometries at the MP2 level of computations. We also explored, theoretically and systematically, scenarios in which the electronic structure of neutral C20 is excited to very high spin multiplicity (beyond triplet state), and local minimum molecular geometries with cage structures are well characterized. We anticipate that such structural resistance to excitation and ionization delivers a prolonged lifetime necessary for the spectroscopic detection of this interesting molecule and its cations in space and potentially in planetary nebulae (PN).

Subtilase SBT5.2 inactivates flagellin immunogenicity in the plant apoplast

Most angiosperm plants recognise the 22-residue flagellin (flg22) epitope in bacterial flagellin via homologs of cell surface receptor FLS2 (flagellin sensitive-2) and mount pattern-triggered immune responses. However, flg22 is buried within the flagellin protein indicating that proteases might be required for flg22 release. Here, we demonstrate the extracellular subtilase SBT5.2 not only releases flg22, but also inactivates the immunogenicity of flagellin and flg22 by cleaving within the flg22 epitope, consistent with previous reports that flg22 is unstable in the apoplast. The prolonged lifetime of flg22 in sbt5.2 mutant plants results in increased bacterial immunity in priming assays, indicating that SBT5.2 counterbalances flagellin immunogenicity to provide spatial-temporal control and restrict costly immune responses and that bacteria take advantage of the host proteolytic machinery to avoid detection by flagellin having a protease-sensitive flg22 epitope.

(Invited) Pt-Alloy Anode and Cathode Catalysts for PEFCs

The R&D of highly active and durable cathode catalysts for the oxygen reduction reaction (ORR: O2 + 4H+ + 4e−→2H2O) is very important for polymer electrolyte fuel cells (PEFCs). Bimetallic alloys of Pt such as Pt−Co exhibit higher ORR activities than that of pure Pt. It was found for polycrystalline Pt alloy electrodes that the dissolution of the surface was followed by a rearrangement of the Pt atoms, resulting in a Pt-skin layer, which can protect the underlying bulk alloy.1, 2 It was also shown that a modified electronic structure at the Pt-skin layer induced enhanced ORR activity.1, 2 Such Pt-skin/Pt alloy electrodes were found to maintain activities for the hydrogen oxidation reaction (HOR: H2 →2H+ + 2e−) in the presence of CO.3 However, in accelerated stress tests (ASTs) of Pt alloys in both states of bulk and nanoparticle (NP) in a half cell with a flow of hot acid solution (> 70°C), further dealloying certainly resulted in a deactivation of ORR and HOR by the formation of thicker Pt layer.1 −3 Thus, an essential point is the formation of a stable and uniformly thin Pt-skin layer, which can protect the underlying alloy from corrosion, as well as multilateral analyses of the electrocatalysis (for the ORR and HOR) and the degradation mechanism, towards designing new potential catalysts.This presentation consists of the following topics for the cathode and anode catalysts. Effect of Underlying Co Content on ORR Activity at Pt-Skin/Pt100−x Co x (111) Single Crystal Electrodes4, 5 Because the surfaces of Pt alloy NPs usually consist of low-index facets such as (111), (100), and (110), well-defined alloy single crystals are essential to clarify the effects of the atomic arrangement on the activity. The ORR activities at a series of (111), (100), and (110) facets of Pt100−x Co x single crystals were examined by rotating disk electrodes in 0.1 M HClO4. The Pt-skin/Pt73Co27(111) electrode exhibited the highest value of kinetically-controlled area-specific activity, jk at 0.9 V, which was about 27 times higher than that on pure Pt(111).4 We clarified the layer-by-layer composition of Pt and Co by in-situ surface X-ray scattering (SXS), together with the modified electronic structure by ex-situ angle-resolved, grazing-incidence XPS (ARGI-XPS).5 Enhancement in the ORR Activity and Durability at Stabilized Pt-Skin–PtCo Catalysts6 − 8 We have successfully prepared PtCo alloy NPs, having one to two atomic layers of stabilized Pt-skin (Pt x AL), supported on carbon (PtxAL–PtCo/C). These catalysts exhibited high mass activity for the ORR, together with high durability.6, 7 A dramatic change in the crystal structure of Pt x AL–PtCo/C by potential cycles was analyzed.8 Suppression of H2O2 Formation at Pt-Skin–PtCo Anode Catalysts for Mitigation of PEM Degradation9 Polymer electrolyte membranes (PEMs) are degraded by ·OH radicals, generated from H2O2, which is produced by a reaction of hydrogen adsorbed on the Pt anode with O2 diffusing through the PEM. The H2O2 formation at Pt x AL–PtCo/C anode was found to be suppressed remarkably with maintaining superlative activity for the HOR.9, 10 We demonstrated a noticeably prolonged lifetime of a Nafion-PEM in a single cell test by using Pt-skin–PtCo/C anode, which was designed to be nearly identical with the in-house catalyst and prepared at 10 gram-scale by TKK.9 The mechanism for the suppression of H2O2 was analyzed by in-situ XAS.This work was supported by funds from the New Energy and Industrial Technology Development Organization (NEDO) of Japan. References H. Uchida, H. Yano, M. Wakisaka, M. Watanabe, Electrochemistry, 79, 303 (2011).M. Watanabe, D. A. Tryk, M. Wakisaka, H. Yano, H. Uchida, Electrochim. Acta, 84, 187 (2012).H. Uchida, K. Izumi, K. Aoki, M. Watanabe, Phys. Chem. Chem. Phys., 11, 1771 (2009).S. Kobayashi, M. Wakisaka, D. A. Tryk, A. Iiyama, H. Uchida, J. Phys. Chem. C, 121,11234 (2017).S. Kobayashi, M. Aoki, M. Wakisaka, T. Kawamoto, R. Shirasaka, K. Suda, D. A. Tryk, J. Inukai, T. Kondo, H. Uchida, ACS Omega, 3, 154 (2018).M. Chiwata, H. Yano, S. Ogawa, M. Watanabe, A. Iiyama, H. Uchida, Electrochemistry, 84, 133 (2016).M. Watanabe, H. Yano, D. A. Tryk, H. Uchida, J. Electrochem. Soc., 163, F455 (2016).H. Yano, N Takao, M. Arao, M. Matsumoto, T. Itoh, H. Imai, A. Iiyama, J .Inukai, H. Uchida, ACS Appl. Nano Mater., 2, 7473 (2019).G. Shi, D. A. Tryk, T. Iwataki, H. Yano, M. Uchida, A. Iiyama, H. Uchida, J. Mater. Chem. A, 8, 1091 (2020).G. Shi, H. Yano, D. A. Tryk, A. Iiyama, H. Uchida, ACS Catal., 7, 267 (2017).

2D Ga2S3 Heterostructured Catalyst with Highly Enhanced Photocatalytic Activity

In contrast to most composite nanostructured catalysts, two-dimensional Ga2S3 semiconductors and ultrathin graphitic-related materials, g-C3N4 heterojunction photocatalysts, are highly efficient photocatalysts for the removal of methylene blue from aqueous solutions because of their extraordinarily stable absorption and physical and optoelectrical properties. The activities of Ga2S3 nanosheet catalysts are 40% higher than those of commercial P25-TiO2 catalysts. In comparison with the performances of Ga2S3 and g-C3N4 photocatalysts, light absorption by the Ga2S3/g-C3N4 heterostructures in the visible region was at least 2.53 and 2.97 times higher, and their photocatalytic efficiencies increased by more than 2.23 and 2.96 times, respectively. The efficient separation and prolonged lifetimes of photogenerated charge carriers enhanced the photocatalytic activity for degradation. In addition, the parameters of the synthesis process for finely uniform, promising Ga2S3/g-C3N4 heterostructured nanomaterials were investigated; such parameters included the precursor amount (Ga, S, and melamine), annealing temperature, and reaction time, and their effects on the structural properties and photocatalytic performance were studied. The detailed mechanism of the photocatalytic system was evaluated through a free radical scavenging experiment, electron paramagnetic resonance spectroscopy, and time-resolved fluorescence spectroscopy. Pseudo-first-order kinetics models were used to describe the efficient photocatalysis of methylene blue photodegradation by the Ga2S3/g-C3N4 heterostructures over different reaction times. e−, •OH, and •O2 – radicals were confirmed as the major reactive oxidative species, and the degradation products were determined. This study is beneficial because it will promote future research on the use of renewable, sustainable resources in photocatalytic applications.

Conjugated hypercrosslinked polymers for in situ imprinting, selective sorption, and fluorescent turn-on sensing of oxalic acid.

Hypercrosslinked polymer (HCP) is a subclass of porous organic polymer possessing abundant microporosity, tailor-made functionality, and excellent stability. It features low-cost and easily direct knitting synthesis, facilitating the construction of π-conjugated frameworks with fluorescent properties by properly selecting building blocks (BBs) and linkers. Simultaneous imprinting of target molecules into the conjugated HCPs will create selective sorbents and sensors. We prepared several BBs to be polymerized with a terephthaloyl chloride (TCL) linker through Friedel-Crafts acylation in the presence of some imprinting molecules to clarify the best collocation for the advancement of imprinted polymer. With the highest increase in fluorescence intensity (F), the conjugated HCP comprised of dibenzofuran (DBF) and TCL was selected as contact with oxalic acid (OA). The OA-imprinted DBF-TCL (MICHP) was characterized by FTIR-approved structures, amorphous SEM images, TGA degradation at 390°C, blue-shift emission, prolonged lifetime, and aggregation-caused quenching. The increase in F was proportional to OA concentration (0.17-20.0μM, RSD = 1.6%, LOD = 0.03μM) in THF/H2O (pH 7.0) containing MICHP (0.2mg/3mL) and 6.0min equilibrium. The F increase arose from inhibiting the quenching of photo-induced electron transfer because of protonation and association of OA with imprinted cavities. Langmuir-Freundlich isotherm precisely modeled the imprinted cavity affinity for OA with binding sites of 114.5μmol/g and heterogeneity of 0.939. The cavities distinctly recognized OA and malonic acid interferant, presenting imprinting factor (4.76 vs. 1.35), specific sorption ratio (79.0% vs. 25.7%), and relative selectivity coefficient (3.935 vs. 0.779), which sustained the precise measurements of OA in tomato, taro, and urine. This study approved a cheap and easy strategy to implant fluorescent and imprinting functions in HCPs using as sorbent and sensor through Friedel-Crafts acylation of electrophilic crosslinker and nucleophilic BB, especially those with heterocyclics.

Multi-Spectroscopic and Molecular Modeling Studies of Interactions Between Anionic Porphyrin and Human Serum Albumin.

The subject of this study is the interaction between 5,10,15,20-tetrakis (4-sulfonatophenyl)-porphyrin (TSPP), a potential photosensitizer for photodynamic therapy (PDT) and radiotherapy, and human serum albumin (HSA), a crucial protein in the body. The main objective was to investigate the binding mechanisms, structural changes, and potential implications of these interactions for drug delivery and therapeutic applications. Spectroscopic techniques and computational methods were employed to investigate the mechanism and effects of TSPP binding by HSA. The results suggest the possibility of simultaneous binding of three TSPP ions at binding sites of different affinity within albumin. The estimated values of the binding constant Kb for these sites were in the range of 0.6 to 6.6 μM-1. Laser flash photolysis indicated the stabilization of TSPP in the HSA structure, which resulted in prolonged lifetimes of the excited states (singlet and triplet) of porphyrin. Circular dichroism analysis was used to assess the changes in the secondary and tertiary structures of HSA upon TSPP binding. An analysis of the molecular docking results allowed us to identify the preferred TSPP binding sites within HSA and provided information on the specific interactions of amino acids involved in the stabilization of TSPP-HSA complexes. The estimated free energy of the binding of porphyrin at the three most favorable docking sites found in the HSA structure that was considered native were in the range of -80 to -41 kcal/mol. Finally, thermal unfolding studies showed that TSPP increased the stability of the secondary structure of albumin. All these findings contribute to the understanding of the interactions between TSPP and HSA, offering valuable insights for the development of novel cancer therapy approaches.

Efficient Blade-Coated Wide-Bandgap and Tandem Perovskite Solar Cells via a Three-Step Restraining Strategy.

Blade-coating techniques have attracted significant attention for perovskite solar cells (PSCs)due to their high precursor utilization and simplicity. However, the power conversion efficiency (PCE) of blade-coated PSCs often lags behind that of spin-coated devices, mainly due to difficulties in precisely controlling perovskite film formation during pre-nucleation, heterogeneous nucleation, and crystallization in the blade-coating and N2-knife drying processes. In this work, a three-step restraining strategy is introduced utilizing functional glycine amide hydrochloride to regulate pre-nucleation clustering, suppress excessive heterogeneous nucleation, and decelerate crystallization, enabling comprehensive control of the perovskite film formation processes. This approach results in enlarged grains, reduced defect densities, and highly oriented crystalline wide-bandgap perovskite films with significantly prolonged carrier lifetimes, achieving a maximum PCE of 19.97% for 1.77 eV-bandgap blade-coated PSCs. Furthermore, two-terminal tandem cells, composed of wide-bandgap perovskite top cells and 1.25 eV-bandgap perovskite bottom cells fabricated via blade coating, yield an impressive PCE of 27.11% (stabilized at 26.87%). This study offers comprehensive insights into controlling pre-nucleation, heterogeneous nucleation, and crystallization during blade coating, providing valuable guidance for developing high-performance, large-area devices in the future.