Jenny Schneider

Importance: Piperacillin/tazobactam solutions are frequently administered as 24-hour continuous intravenous infusions to patients in Hospital in the Home (HITH) programs and the accuracy of administration from elastomeric pumps (‘EMPs’) is important. Objective: This study aimed to review the effect of piperacillin/tazobactam solution concentration on the rate of infusion from ‘EMPs’ to patients in the clinical HITH setting, by reviewing the volumes of residual and administered solution. Design: This retrospective audit was conducted from 6/11/2021 to 14/6/2023 and the following information was collected for patients treated with piperacillin/tazobactam EMPs: patient details, treatment indication, EMP solution concentration, time of EMP attachment/detachment, volume of antibiotic solution remaining (if any), EMP type/brand, central line type, and central line issues (if any). Setting: This study was conducted in the Central Coast Health District (CCLHD) HITH in New South Wales, Australia. Participants: Patients treated with 24-hour continuous intravenous infusions of piperacillin/tazobactam via EMPs on the CCLHD HITH service. Results: For all EMPs over all times, a median residual volume of 30mL (IQR: 0-50mL) was recorded (n=2152). Piperacillin/tazobactam 75mg/mL (18g/240mL) EMPs had a median residual volume of 50mL (IQR 20-70mL) when removed at ‘all times’ (n=170) and ‘=24 hours’ (n=184). Residual volumes >15% occurred 48% of the time when removed ‘=24 hours’ (n=325). Piperacillin/tazobactam 75mg/mL (18g/240mL) EMPs were significantly less likely to be removed (at ≥24 hours) with ≤15% residual volume compared to the piperacillin/tazobactam 37.5mg/mL (9g/240mL; p<0.001) or 56.25mg/mL (13.5g/240mL; p=0.008) EMPs. The mean percentage of piperacillin/tazobactam solution administered was significantly lower for the 75mg/mL EMP, with mean differences of -7.5% (95% CI [3.4, 11.6]; p<0.001) and -9.7% (95% CI [4.2, 15.2]; p=0.001) compared with the piperacillin tazobactam 56.25mg/mL (13.5g/240mL) and 37.5mg/mL (9g/240mL) EMPs respectively. Conclusion: The piperacillin/tazobactam 75mg/mL (18g/240mL) solution significantly slowed the rate of infusion from the EMP compared to the piperacillin/tazobactam 37.5mg/mL (9g/240mL) and piperacillin/tazobactam 56.25mg/mL (13.5g/240mL) solutions. The appropriateness of piperacillin/tazobactam 75mg/mL (18g/240mL) EMPs in the clinical HITH setting should be carefully considered.

Strategies for tuning structural and (opto-)­electronic properties are fundamental to the rational design of functional materials. Here, we present a molecular-design approach that enables precise modulation of the optoelectronic properties of covalent organic frameworks (COFs) through single-atom halogen substitution on π-extended anthracene linkers. Using a Wurster-type tetratopic amine (W–NH₂) and a series of anthracene-based dialdehydes bearing H, Cl, Br, or I at the 2-position, a family of imine-linked COFs, W-A-X (X = H, Cl, Br, I), was synthesized. The halogen substituent strongly influences framework formation, with brominated COFs forming substantially larger crystalline domains than the unsubstituted analogue. UV–vis absorption and photoluminescence measurements reveal a systematic redshift across the series (H < Cl < Br < I), demonstrating that a single-atom modification tunes the optical response. In addition, the significantly longer excited-state lifetime of W-A-Cl COF highlights the strengthened donor–acceptor interactions induced by the more electron-withdrawing chlorine substituent, further confirming the decisive role of single-atom functionalization in controlling excited-state dynamics. Time-dependent density functional theory calculations on both isolated fragments and extended COF models attribute the observed trends in optical response to halogen-induced changes in the COF band structure and provide a mechanistic understanding of how a single-atom substitution influences the optoelectronic properties of the extended π-framework. Overall, this study establishes single-atom halogen substitution as a powerful and modular tool for tailoring the structural and optical properties of anthracene-based COFs.

Covalent Organic Frameworks (COFs) have emerged as versatile platforms for the rational design of heterogeneous CO ₂ electrocatalysts, offering molecular‐level precision due to their well‐ordered, porous structures. While COF‐based hybrid electrocatalysts have demonstrated potential in lab‐scale electrochemical cells with liquid electrolytes, their application in industry‐relevant architectures remains largely unexplored. Here, the first successful integration of a phenanthroline‐based 2D COF, modified with Mn ^I single catalytic sites, into a catholyte‐free membrane‐electrode‐assembly (MEA) cell for CO ₂ electroreduction is presented. The crystalline COF catalyst achieves an outstanding turnover frequency of 617 h⁻ ¹ (quantified per total concentration of catalytic sites) and a CO evolution of 222 µmol cm⁻ ² (at a full‐cell potential of 2.8 V) within 30 min. Moreover, the COF structure actively suppresses Mn⁰–Mn⁰ dimer formation and supports stable operation at high potentials with a partial current density of 23 mA cm ⁻² . The synergy between the crystalline nature of the COF and the MEA cell architecture, facilitating direct interactions between the modified electrode and the CO ₂ gas, enhances both the catalytic activity and stability. This work paves the way for broader adoption of COF‐based hybrid materials in advanced electrocatalytic CO ₂ reduction technologies.

Covalent organic frameworks (COFs) represent a new class of organic photocatalysts for the hydrogen evolution reaction (HER). While the influence of COF structural and optoelectronic properties on HER is well‐studied, the role of surface charge in optimizing interfacial interactions with reactants remains underexplored. In this study, it is demonstrated that converting imine to amide linkages in a thiophene‐based COF allows for altering surface charge through different protonation behaviors of the linkages. Zeta potential measurements reveal that the amide‐linked COF, due to its lower basicity, is deprotonated and negatively charged in the presence of ascorbic acid, while the imine‐linked COF is protonated and positively charged. This electrostatic contrast drives the photoreduction of [PtCl ₆ ] ² ⁻ to Pt, with the imine‐linked COF yielding uniformly distributed small Pt particles (1–2 nm), whereas the amide‐linked COF forms larger Pt particles (up to 100 nm). The amide‐linked COF, acting as an antenna that facilitates interdomain electron transport along COF agglomerates, promotes both Pt growth and subsequent proton reduction demonstrating a 300% increase in photocatalytic HER rate compared to its imine form. This work introduces surface charge modulation as a novel tool for controlling photocatalytic processes in COF‐based systems expanding the COF functionality in photocatalysis.

Carbon dots (CDs) are environmentally benign, strongly photoluminescent, metal free nanoparticles. Interfacing them with tailor-made organic semiconductors possesing an ordered channel structure such as covalent organic frameworks (COFs) promises to yield multifunctional materials. In this study, microwave-derived CDs are successfully incorporated into the porous structure of COF in a one-pot synthesis in which the condensation reaction between benzo[1,2-b:4,5-b′]dithiophene-2,6-dicarboxaldehyde (BDT) and 1,1,2,2-tetra(p-aminophenyl)ethylene (ETTA) is conducted in the presence of CDs. A detailed structural and optoelectronic characterization of the COF/CDs composite reveals that upon tuning the CDs loadings encapsulated in COF the interaction between both components can be controlled allowing the switch between energy and charge transfer. At CDs loadings ⩽20 wt%, strong binding of CDs to the COF enables charge transfer evinced from the quenched photoluminescence (PL) of both components and accelerated exciton decay kinetics of the COF. At CDs loadings ⩾30 wt% Förster resonance energy transfer from CDs to COF prevails, leading to enhanced COF PL. Our study underlines the interaction mechanism in organic composites and provides the knowledge required for the design of novel functional materials with applications in photocatalysis, optoelectronics and sensing.

The rational design of organic–inorganic hybrids to the photocatalytic reduction of CO₂ is reviewed, pointing to the challenges and perspectives towards both fundamental understanding and potential upscaling.

The catastrophic consequences of increased power consumption, such as drastically rising CO₂ levels, natural disasters, environmental pollution and dependence on fossil fuels supplied by countries with totalitarian regimes, illustrate the urge to develop sustainable technologies for energy generation. Photocatalysis presents eco-friendly means for fuels production via solar-to-chemical energy conversion. The conversion efficiency of a photocatalyst critically depends on charge carrier processes taking place in the ultrafast time regime. Transient absorption spectroscopy (TAS) serves as a perfect tool to track those processes. The spectral and kinetic characterization of charge carriers is indispensable for the elucidation of photocatalytic mechanisms and for the development of new materials. Hence, in this review, we will first present the basics of TAS and subsequently discuss the procedure required for the interpretation of the transient absorption spectra and transient kinetics. The discussion will include specific examples for charge carrier processes occurring in conventional and plasmonic semiconductors. Graphical abstract

The presence of pollutants, e.g., pharmaceutical residues and industrial pollutants causes serious risks and irreversible damage to public health and ecological balance. Semiconductor-based photocatalysis is an attractive way to treat polluted water. Rational design and nanostructuring of semiconductors with visible light absorption and prominent surfaces could strengthen surface-interface reactions, resulting in improved photocatalytic degradation. Herein, layered structured perovskites Bi₄Ti₃O₁₂ (BTO) were synthesized by an ionic liquid [1-butyl-3-methylimidazolium iodide (Bmim)I] assisted approach. The precise tuning of synthetic conditions allowed formations of various microstructures, including spherical nanoparticles, nanoplates and nanorods, respectively. The optical analyses demonstrated that samples were typically visible light absorbents with narrow band gap energies (2.96–2.73 eV), and displayed pronounced degradation for pharmaceutical residues under visible light illumination. The factors responsible for the high efficiency of BTO photocatalysts were discussed in terms of unique structure, optical alignment, dipole induced carrier separation and formation of active radicals. Among studied samples, the nanorod shaped BTO showed 1.31 and 1.46 times higher apparent rate constants for tetracycline and ibuprofen degradation than its counterparts (spherical nanoparticles and nanoplates), respectively. The better performance of nanorods was ascribed to their higher visible light harvesting ability. Importantly, BTO nanorods exhibited nonselective degradation activity for diverse pollutants of pharmaceutical residues and industrial contaminants. This work demonstrates the unique strategy of microstructure regulation and a wide range of applications of layered perovskites for environmental remediation.